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/* vi: set sw=4 ts=4: */
/*
* A prototype Bourne shell grammar parser.
* Intended to follow the original Thompson and Ritchie
* "small and simple is beautiful" philosophy, which
* incidentally is a good match to today's BusyBox.
*
* Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
* Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
* Credits:
* The parser routines proper are all original material, first
* written Dec 2000 and Jan 2001 by Larry Doolittle. The
* execution engine, the builtins, and much of the underlying
* support has been adapted from busybox-0.49pre's lash, which is
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
* written by Erik Andersen <andersen@codepoet.org>. That, in turn,
* is based in part on ladsh.c, by Michael K. Johnson and Erik W.
* Troan, which they placed in the public domain. I don't know
* how much of the Johnson/Troan code has survived the repeated
* rewrites.
*
* Other credits:
* o_addchr derived from similar w_addchar function in glibc-2.2.
* parse_redirect, redirect_opt_num, and big chunks of main
* and many builtins derived from contributions by Erik Andersen.
* Miscellaneous bugfixes from Matt Kraai.
*
* There are two big (and related) architecture differences between
* this parser and the lash parser. One is that this version is
* actually designed from the ground up to understand nearly all
* of the Bourne grammar. The second, consequential change is that
* the parser and input reader have been turned inside out. Now,
* the parser is in control, and asks for input as needed. The old
* way had the input reader in control, and it asked for parsing to
* take place as needed. The new way makes it much easier to properly
* handle the recursion implicit in the various substitutions, especially
* across continuation lines.
*
* TODOs:
* grep for "TODO" and fix (some of them are easy)
* special variables (done: PWD, PPID, RANDOM)
* tilde expansion
* aliases
* follow IFS rules more precisely, including update semantics
* builtins mandated by standards we don't support:
* [un]alias, command, fc, getopts, newgrp, readonly, times
* make complex ${var%...} constructs support optional
* make here documents optional
*
* Bash compat TODO:
* redirection of stdout+stderr: &> and >&
* reserved words: function select
* advanced test: [[ ]]
* process substitution: <(list) and >(list)
* =~: regex operator
* let EXPR [EXPR...]
* Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
* If the last arg evaluates to 0, let returns 1; 0 otherwise.
* NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
* ((EXPR))
* The EXPR is evaluated according to ARITHMETIC EVALUATION.
* This is exactly equivalent to let "EXPR".
* $[EXPR]: synonym for $((EXPR))
*
* Won't do:
* In bash, export builtin is special, its arguments are assignments
* and therefore expansion of them should be "one-word" expansion:
* $ export i=`echo 'a b'` # export has one arg: "i=a b"
* compare with:
* $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
* ls: cannot access i=a: No such file or directory
* ls: cannot access b: No such file or directory
* Note1: same applies to local builtin.
* Note2: bash 3.2.33(1) does this only if export word itself
* is not quoted:
* $ export i=`echo 'aaa bbb'`; echo "$i"
* aaa bbb
* $ "export" i=`echo 'aaa bbb'`; echo "$i"
* aaa
*/
#if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
|| defined(__APPLE__) \
)
# include <malloc.h> /* for malloc_trim */
#endif
#include <glob.h>
/* #include <dmalloc.h> */
#if ENABLE_HUSH_CASE
# include <fnmatch.h>
#endif
#include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
#include "unicode.h"
#include "shell_common.h"
#include "math.h"
#include "match.h"
#if ENABLE_HUSH_RANDOM_SUPPORT
# include "random.h"
#else
# define CLEAR_RANDOM_T(rnd) ((void)0)
#endif
#ifndef PIPE_BUF
# define PIPE_BUF 4096 /* amount of buffering in a pipe */
#endif
/* Not every libc has sighandler_t. Fix it */
typedef void (*hush_sighandler_t)(int);
#define sighandler_t hush_sighandler_t
//config:config HUSH
//config: bool "hush"
//config: default y
//config: help
//config: hush is a small shell (25k). It handles the normal flow control
//config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
//config: case/esac. Redirections, here documents, $((arithmetic))
//config: and functions are supported.
//config:
//config: It will compile and work on no-mmu systems.
//config:
//config: It does not handle select, aliases, tilde expansion,
//config: &>file and >&file redirection of stdout+stderr.
//config:
//config:config HUSH_BASH_COMPAT
//config: bool "bash-compatible extensions"
//config: default y
//config: depends on HUSH
//config: help
//config: Enable bash-compatible extensions.
//config:
//config:config HUSH_BRACE_EXPANSION
//config: bool "Brace expansion"
//config: default y
//config: depends on HUSH_BASH_COMPAT
//config: help
//config: Enable {abc,def} extension.
//config:
//config:config HUSH_HELP
//config: bool "help builtin"
//config: default y
//config: depends on HUSH
//config: help
//config: Enable help builtin in hush. Code size + ~1 kbyte.
//config:
//config:config HUSH_INTERACTIVE
//config: bool "Interactive mode"
//config: default y
//config: depends on HUSH
//config: help
//config: Enable interactive mode (prompt and command editing).
//config: Without this, hush simply reads and executes commands
//config: from stdin just like a shell script from a file.
//config: No prompt, no PS1/PS2 magic shell variables.
//config:
//config:config HUSH_SAVEHISTORY
//config: bool "Save command history to .hush_history"
//config: default y
//config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
//config: help
//config: Enable history saving in hush.
//config:
//config:config HUSH_JOB
//config: bool "Job control"
//config: default y
//config: depends on HUSH_INTERACTIVE
//config: help
//config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
//config: command (not entire shell), fg/bg builtins work. Without this option,
//config: "cmd &" still works by simply spawning a process and immediately
//config: prompting for next command (or executing next command in a script),
//config: but no separate process group is formed.
//config:
//config:config HUSH_TICK
//config: bool "Process substitution"
//config: default y
//config: depends on HUSH
//config: help
//config: Enable process substitution `command` and $(command) in hush.
//config:
//config:config HUSH_IF
//config: bool "Support if/then/elif/else/fi"
//config: default y
//config: depends on HUSH
//config: help
//config: Enable if/then/elif/else/fi in hush.
//config:
//config:config HUSH_LOOPS
//config: bool "Support for, while and until loops"
//config: default y
//config: depends on HUSH
//config: help
//config: Enable for, while and until loops in hush.
//config:
//config:config HUSH_CASE
//config: bool "Support case ... esac statement"
//config: default y
//config: depends on HUSH
//config: help
//config: Enable case ... esac statement in hush. +400 bytes.
//config:
//config:config HUSH_FUNCTIONS
//config: bool "Support funcname() { commands; } syntax"
//config: default y
//config: depends on HUSH
//config: help
//config: Enable support for shell functions in hush. +800 bytes.
//config:
//config:config HUSH_LOCAL
//config: bool "Support local builtin"
//config: default y
//config: depends on HUSH_FUNCTIONS
//config: help
//config: Enable support for local variables in functions.
//config:
//config:config HUSH_RANDOM_SUPPORT
//config: bool "Pseudorandom generator and $RANDOM variable"
//config: default y
//config: depends on HUSH
//config: help
//config: Enable pseudorandom generator and dynamic variable "$RANDOM".
//config: Each read of "$RANDOM" will generate a new pseudorandom value.
//config:
//config:config HUSH_EXPORT_N
//config: bool "Support 'export -n' option"
//config: default y
//config: depends on HUSH
//config: help
//config: export -n unexports variables. It is a bash extension.
//config:
//config:config HUSH_MODE_X
//config: bool "Support 'hush -x' option and 'set -x' command"
//config: default y
//config: depends on HUSH
//config: help
//config: This instructs hush to print commands before execution.
//config: Adds ~300 bytes.
//config:
//config:config MSH
//config: bool "msh (deprecated: aliased to hush)"
//config: default n
//config: select HUSH
//config: help
//config: msh is deprecated and will be removed, please migrate to hush.
//config:
//applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
//applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
//applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
//applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
//kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
//kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
/* -i (interactive) and -s (read stdin) are also accepted,
* but currently do nothing, therefore aren't shown in help.
* NOMMU-specific options are not meant to be used by users,
* therefore we don't show them either.
*/
//usage:#define hush_trivial_usage
//usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
//usage:#define hush_full_usage "\n\n"
//usage: "Unix shell interpreter"
//usage:#define msh_trivial_usage hush_trivial_usage
//usage:#define msh_full_usage hush_full_usage
//usage:#if ENABLE_FEATURE_SH_IS_HUSH
//usage:# define sh_trivial_usage hush_trivial_usage
//usage:# define sh_full_usage hush_full_usage
//usage:#endif
//usage:#if ENABLE_FEATURE_BASH_IS_HUSH
//usage:# define bash_trivial_usage hush_trivial_usage
//usage:# define bash_full_usage hush_full_usage
//usage:#endif
/* Build knobs */
#define LEAK_HUNTING 0
#define BUILD_AS_NOMMU 0
/* Enable/disable sanity checks. Ok to enable in production,
* only adds a bit of bloat. Set to >1 to get non-production level verbosity.
* Keeping 1 for now even in released versions.
*/
#define HUSH_DEBUG 1
/* Slightly bigger (+200 bytes), but faster hush.
* So far it only enables a trick with counting SIGCHLDs and forks,
* which allows us to do fewer waitpid's.
* (we can detect a case where neither forks were done nor SIGCHLDs happened
* and therefore waitpid will return the same result as last time)
*/
#define ENABLE_HUSH_FAST 0
/* TODO: implement simplified code for users which do not need ${var%...} ops
* So far ${var%...} ops are always enabled:
*/
#define ENABLE_HUSH_DOLLAR_OPS 1
#if BUILD_AS_NOMMU
# undef BB_MMU
# undef USE_FOR_NOMMU
# undef USE_FOR_MMU
# define BB_MMU 0
# define USE_FOR_NOMMU(...) __VA_ARGS__
# define USE_FOR_MMU(...)
#endif
#include "NUM_APPLETS.h"
#if NUM_APPLETS == 1
/* STANDALONE does not make sense, and won't compile */
# undef CONFIG_FEATURE_SH_STANDALONE
# undef ENABLE_FEATURE_SH_STANDALONE
# undef IF_FEATURE_SH_STANDALONE
# undef IF_NOT_FEATURE_SH_STANDALONE
# define ENABLE_FEATURE_SH_STANDALONE 0
# define IF_FEATURE_SH_STANDALONE(...)
# define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
#endif
#if !ENABLE_HUSH_INTERACTIVE
# undef ENABLE_FEATURE_EDITING
# define ENABLE_FEATURE_EDITING 0
# undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
# define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
#endif
/* Do we support ANY keywords? */
#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
# define HAS_KEYWORDS 1
# define IF_HAS_KEYWORDS(...) __VA_ARGS__
# define IF_HAS_NO_KEYWORDS(...)
#else
# define HAS_KEYWORDS 0
# define IF_HAS_KEYWORDS(...)
# define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
#endif
/* If you comment out one of these below, it will be #defined later
* to perform debug printfs to stderr: */
#define debug_printf(...) do {} while (0)
/* Finer-grained debug switches */
#define debug_printf_parse(...) do {} while (0)
#define debug_print_tree(a, b) do {} while (0)
#define debug_printf_exec(...) do {} while (0)
#define debug_printf_env(...) do {} while (0)
#define debug_printf_jobs(...) do {} while (0)
#define debug_printf_expand(...) do {} while (0)
#define debug_printf_varexp(...) do {} while (0)
#define debug_printf_glob(...) do {} while (0)
#define debug_printf_list(...) do {} while (0)
#define debug_printf_subst(...) do {} while (0)
#define debug_printf_clean(...) do {} while (0)
#define ERR_PTR ((void*)(long)1)
#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
#define _SPECIAL_VARS_STR "_*@$!?#"
#define SPECIAL_VARS_STR ("_*@$!?#" + 1)
#define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
#if ENABLE_HUSH_BASH_COMPAT
/* Support / and // replace ops */
/* Note that // is stored as \ in "encoded" string representation */
# define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
# define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
# define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
#else
# define VAR_ENCODED_SUBST_OPS "%#:-=+?"
# define VAR_SUBST_OPS "%#:-=+?"
# define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
#endif
#define SPECIAL_VAR_SYMBOL 3
struct variable;
static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
/* This supports saving pointers malloced in vfork child,
* to be freed in the parent.
*/
#if !BB_MMU
typedef struct nommu_save_t {
char **new_env;
struct variable *old_vars;
char **argv;
char **argv_from_re_execing;
} nommu_save_t;
#endif
enum {
RES_NONE = 0,
#if ENABLE_HUSH_IF
RES_IF ,
RES_THEN ,
RES_ELIF ,
RES_ELSE ,
RES_FI ,
#endif
#if ENABLE_HUSH_LOOPS
RES_FOR ,
RES_WHILE ,
RES_UNTIL ,
RES_DO ,
RES_DONE ,
#endif
#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
RES_IN ,
#endif
#if ENABLE_HUSH_CASE
RES_CASE ,
/* three pseudo-keywords support contrived "case" syntax: */
RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
RES_MATCH , /* "word)" */
RES_CASE_BODY, /* "this command is inside CASE" */
RES_ESAC ,
#endif
RES_XXXX ,
RES_SNTX
};
typedef struct o_string {
char *data;
int length; /* position where data is appended */
int maxlen;
int o_expflags;
/* At least some part of the string was inside '' or "",
* possibly empty one: word"", wo''rd etc. */
smallint has_quoted_part;
smallint has_empty_slot;
smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
} o_string;
enum {
EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
EXP_FLAG_GLOB = 0x2,
/* Protect newly added chars against globbing
* by prepending \ to *, ?, [, \ */
EXP_FLAG_ESC_GLOB_CHARS = 0x1,
};
enum {
MAYBE_ASSIGNMENT = 0,
DEFINITELY_ASSIGNMENT = 1,
NOT_ASSIGNMENT = 2,
/* Not an assigment, but next word may be: "if v=xyz cmd;" */
WORD_IS_KEYWORD = 3,
};
/* Used for initialization: o_string foo = NULL_O_STRING; */
#define NULL_O_STRING { NULL }
#ifndef debug_printf_parse
static const char *const assignment_flag[] = {
"MAYBE_ASSIGNMENT",
"DEFINITELY_ASSIGNMENT",
"NOT_ASSIGNMENT",
"WORD_IS_KEYWORD",
};
#endif
typedef struct in_str {
const char *p;
/* eof_flag=1: last char in ->p is really an EOF */
char eof_flag; /* meaningless if ->p == NULL */
char peek_buf[2];
#if ENABLE_HUSH_INTERACTIVE
smallint promptmode; /* 0: PS1, 1: PS2 */
#endif
int last_char;
FILE *file;
int (*get) (struct in_str *) FAST_FUNC;
int (*peek) (struct in_str *) FAST_FUNC;
} in_str;
#define i_getch(input) ((input)->get(input))
#define i_peek(input) ((input)->peek(input))
/* The descrip member of this structure is only used to make
* debugging output pretty */
static const struct {
int mode;
signed char default_fd;
char descrip[3];
} redir_table[] = {
{ O_RDONLY, 0, "<" },
{ O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
{ O_CREAT|O_RDWR, 1, "<>" },
{ O_RDONLY, 0, "<<" },
/* Should not be needed. Bogus default_fd helps in debugging */
/* { O_RDONLY, 77, "<<" }, */
};
struct redir_struct {
struct redir_struct *next;
char *rd_filename; /* filename */
int rd_fd; /* fd to redirect */
/* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
int rd_dup;
smallint rd_type; /* (enum redir_type) */
/* note: for heredocs, rd_filename contains heredoc delimiter,
* and subsequently heredoc itself; and rd_dup is a bitmask:
* bit 0: do we need to trim leading tabs?
* bit 1: is heredoc quoted (<<'delim' syntax) ?
*/
};
typedef enum redir_type {
REDIRECT_INPUT = 0,
REDIRECT_OVERWRITE = 1,
REDIRECT_APPEND = 2,
REDIRECT_IO = 3,
REDIRECT_HEREDOC = 4,
REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
REDIRFD_CLOSE = -3,
REDIRFD_SYNTAX_ERR = -2,
REDIRFD_TO_FILE = -1,
/* otherwise, rd_fd is redirected to rd_dup */
HEREDOC_SKIPTABS = 1,
HEREDOC_QUOTED = 2,
} redir_type;
struct command {
pid_t pid; /* 0 if exited */
int assignment_cnt; /* how many argv[i] are assignments? */
smallint is_stopped; /* is the command currently running? */
smallint cmd_type; /* CMD_xxx */
#define CMD_NORMAL 0
#define CMD_SUBSHELL 1
#if ENABLE_HUSH_BASH_COMPAT
/* used for "[[ EXPR ]]" */
# define CMD_SINGLEWORD_NOGLOB 2
#endif
#if ENABLE_HUSH_FUNCTIONS
# define CMD_FUNCDEF 3
#endif
smalluint cmd_exitcode;
/* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
struct pipe *group;
#if !BB_MMU
char *group_as_string;
#endif
#if ENABLE_HUSH_FUNCTIONS
struct function *child_func;
/* This field is used to prevent a bug here:
* while...do f1() {a;}; f1; f1() {b;}; f1; done
* When we execute "f1() {a;}" cmd, we create new function and clear
* cmd->group, cmd->group_as_string, cmd->argv[0].
* When we execute "f1() {b;}", we notice that f1 exists,
* and that its "parent cmd" struct is still "alive",
* we put those fields back into cmd->xxx
* (struct function has ->parent_cmd ptr to facilitate that).
* When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
* Without this trick, loop would execute a;b;b;b;...
* instead of correct sequence a;b;a;b;...
* When command is freed, it severs the link
* (sets ->child_func->parent_cmd to NULL).
*/
#endif
char **argv; /* command name and arguments */
/* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
* and on execution these are substituted with their values.
* Substitution can make _several_ words out of one argv[n]!
* Example: argv[0]=='.^C*^C.' here: echo .$*.
* References of the form ^C`cmd arg^C are `cmd arg` substitutions.
*/
struct redir_struct *redirects; /* I/O redirections */
};
/* Is there anything in this command at all? */
#define IS_NULL_CMD(cmd) \
(!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
struct pipe {
struct pipe *next;
int num_cmds; /* total number of commands in pipe */
int alive_cmds; /* number of commands running (not exited) */
int stopped_cmds; /* number of commands alive, but stopped */
#if ENABLE_HUSH_JOB
int jobid; /* job number */
pid_t pgrp; /* process group ID for the job */
char *cmdtext; /* name of job */
#endif
struct command *cmds; /* array of commands in pipe */
smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
};
typedef enum pipe_style {
PIPE_SEQ = 1,
PIPE_AND = 2,
PIPE_OR = 3,
PIPE_BG = 4,
} pipe_style;
/* Is there anything in this pipe at all? */
#define IS_NULL_PIPE(pi) \
((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
/* This holds pointers to the various results of parsing */
struct parse_context {
/* linked list of pipes */
struct pipe *list_head;
/* last pipe (being constructed right now) */
struct pipe *pipe;
/* last command in pipe (being constructed right now) */
struct command *command;
/* last redirect in command->redirects list */
struct redir_struct *pending_redirect;
#if !BB_MMU
o_string as_string;
#endif
#if HAS_KEYWORDS
smallint ctx_res_w;
smallint ctx_inverted; /* "! cmd | cmd" */
#if ENABLE_HUSH_CASE
smallint ctx_dsemicolon; /* ";;" seen */
#endif
/* bitmask of FLAG_xxx, for figuring out valid reserved words */
int old_flag;
/* group we are enclosed in:
* example: "if pipe1; pipe2; then pipe3; fi"
* when we see "if" or "then", we malloc and copy current context,
* and make ->stack point to it. then we parse pipeN.
* when closing "then" / fi" / whatever is found,
* we move list_head into ->stack->command->group,
* copy ->stack into current context, and delete ->stack.
* (parsing of { list } and ( list ) doesn't use this method)
*/
struct parse_context *stack;
#endif
};
/* On program start, environ points to initial environment.
* putenv adds new pointers into it, unsetenv removes them.
* Neither of these (de)allocates the strings.
* setenv allocates new strings in malloc space and does putenv,
* and thus setenv is unusable (leaky) for shell's purposes */
#define setenv(...) setenv_is_leaky_dont_use()
struct variable {
struct variable *next;
char *varstr; /* points to "name=" portion */
#if ENABLE_HUSH_LOCAL
unsigned func_nest_level;
#endif
int max_len; /* if > 0, name is part of initial env; else name is malloced */
smallint flg_export; /* putenv should be done on this var */
smallint flg_read_only;
};
enum {
BC_BREAK = 1,
BC_CONTINUE = 2,
};
#if ENABLE_HUSH_FUNCTIONS
struct function {
struct function *next;
char *name;
struct command *parent_cmd;
struct pipe *body;
# if !BB_MMU
char *body_as_string;
# endif
};
#endif
/* set -/+o OPT support. (TODO: make it optional)
* bash supports the following opts:
* allexport off
* braceexpand on
* emacs on
* errexit off
* errtrace off
* functrace off
* hashall on
* histexpand off
* history on
* ignoreeof off
* interactive-comments on
* keyword off
* monitor on
* noclobber off
* noexec off
* noglob off
* nolog off
* notify off
* nounset off
* onecmd off
* physical off
* pipefail off
* posix off
* privileged off
* verbose off
* vi off
* xtrace off
*/
static const char o_opt_strings[] ALIGN1 =
"pipefail\0"
"noexec\0"
#if ENABLE_HUSH_MODE_X
"xtrace\0"
#endif
;
enum {
OPT_O_PIPEFAIL,
OPT_O_NOEXEC,
#if ENABLE_HUSH_MODE_X
OPT_O_XTRACE,
#endif
NUM_OPT_O
};
/* "Globals" within this file */
/* Sorted roughly by size (smaller offsets == smaller code) */
struct globals {
/* interactive_fd != 0 means we are an interactive shell.
* If we are, then saved_tty_pgrp can also be != 0, meaning
* that controlling tty is available. With saved_tty_pgrp == 0,
* job control still works, but terminal signals
* (^C, ^Z, ^Y, ^\) won't work at all, and background
* process groups can only be created with "cmd &".
* With saved_tty_pgrp != 0, hush will use tcsetpgrp()
* to give tty to the foreground process group,
* and will take it back when the group is stopped (^Z)
* or killed (^C).
*/
#if ENABLE_HUSH_INTERACTIVE
/* 'interactive_fd' is a fd# open to ctty, if we have one
* _AND_ if we decided to act interactively */
int interactive_fd;
const char *PS1;
const char *PS2;
# define G_interactive_fd (G.interactive_fd)
#else
# define G_interactive_fd 0
#endif
#if ENABLE_FEATURE_EDITING
line_input_t *line_input_state;
#endif
pid_t root_pid;
pid_t root_ppid;
pid_t last_bg_pid;
#if ENABLE_HUSH_RANDOM_SUPPORT
random_t random_gen;
#endif
#if ENABLE_HUSH_JOB
int run_list_level;
int last_jobid;
pid_t saved_tty_pgrp;
struct pipe *job_list;
# define G_saved_tty_pgrp (G.saved_tty_pgrp)
#else
# define G_saved_tty_pgrp 0
#endif
char o_opt[NUM_OPT_O];
#if ENABLE_HUSH_MODE_X
# define G_x_mode (G.o_opt[OPT_O_XTRACE])
#else
# define G_x_mode 0
#endif
smallint flag_SIGINT;
#if ENABLE_HUSH_LOOPS
smallint flag_break_continue;
#endif
#if ENABLE_HUSH_FUNCTIONS
/* 0: outside of a function (or sourced file)
* -1: inside of a function, ok to use return builtin
* 1: return is invoked, skip all till end of func
*/
smallint flag_return_in_progress;
#endif
smallint exiting; /* used to prevent EXIT trap recursion */
/* These four support $?, $#, and $1 */
smalluint last_exitcode;
/* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
smalluint global_args_malloced;
/* how many non-NULL argv's we have. NB: $# + 1 */
int global_argc;
char **global_argv;
#if !BB_MMU
char *argv0_for_re_execing;
#endif
#if ENABLE_HUSH_LOOPS
unsigned depth_break_continue;
unsigned depth_of_loop;
#endif
const char *ifs;
const char *cwd;
struct variable *top_var;
char **expanded_assignments;
#if ENABLE_HUSH_FUNCTIONS
struct function *top_func;
# if ENABLE_HUSH_LOCAL
struct variable **shadowed_vars_pp;
unsigned func_nest_level;
# endif
#endif
/* Signal and trap handling */
#if ENABLE_HUSH_FAST
unsigned count_SIGCHLD;
unsigned handled_SIGCHLD;
smallint we_have_children;
#endif
/* Which signals have non-DFL handler (even with no traps set)?
* Set at the start to:
* (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
* SPECIAL_INTERACTIVE_SIGS are cleared after fork.
* The rest is cleared right before execv syscalls.
* Other than these two times, never modified.
*/
unsigned special_sig_mask;
#if ENABLE_HUSH_JOB
unsigned fatal_sig_mask;
# define G_fatal_sig_mask G.fatal_sig_mask
#else
# define G_fatal_sig_mask 0
#endif
char **traps; /* char *traps[NSIG] */
sigset_t pending_set;
#if HUSH_DEBUG
unsigned long memleak_value;
int debug_indent;
#endif
struct sigaction sa;
char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
};
#define G (*ptr_to_globals)
/* Not #defining name to G.name - this quickly gets unwieldy
* (too many defines). Also, I actually prefer to see when a variable
* is global, thus "G." prefix is a useful hint */
#define INIT_G() do { \
SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
/* memset(&G.sa, 0, sizeof(G.sa)); */ \
sigfillset(&G.sa.sa_mask); \
G.sa.sa_flags = SA_RESTART; \
} while (0)
/* Function prototypes for builtins */
static int builtin_cd(char **argv) FAST_FUNC;
static int builtin_echo(char **argv) FAST_FUNC;
static int builtin_eval(char **argv) FAST_FUNC;
static int builtin_exec(char **argv) FAST_FUNC;
static int builtin_exit(char **argv) FAST_FUNC;
static int builtin_export(char **argv) FAST_FUNC;
#if ENABLE_HUSH_JOB
static int builtin_fg_bg(char **argv) FAST_FUNC;
static int builtin_jobs(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_HELP
static int builtin_help(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_LOCAL
static int builtin_local(char **argv) FAST_FUNC;
#endif
#if HUSH_DEBUG
static int builtin_memleak(char **argv) FAST_FUNC;
#endif
#if ENABLE_PRINTF
static int builtin_printf(char **argv) FAST_FUNC;
#endif
static int builtin_pwd(char **argv) FAST_FUNC;
static int builtin_read(char **argv) FAST_FUNC;
static int builtin_set(char **argv) FAST_FUNC;
static int builtin_shift(char **argv) FAST_FUNC;
static int builtin_source(char **argv) FAST_FUNC;
static int builtin_test(char **argv) FAST_FUNC;
static int builtin_trap(char **argv) FAST_FUNC;
static int builtin_type(char **argv) FAST_FUNC;
static int builtin_true(char **argv) FAST_FUNC;
static int builtin_umask(char **argv) FAST_FUNC;
static int builtin_unset(char **argv) FAST_FUNC;
static int builtin_wait(char **argv) FAST_FUNC;
#if ENABLE_HUSH_LOOPS
static int builtin_break(char **argv) FAST_FUNC;
static int builtin_continue(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_FUNCTIONS
static int builtin_return(char **argv) FAST_FUNC;
#endif
/* Table of built-in functions. They can be forked or not, depending on
* context: within pipes, they fork. As simple commands, they do not.
* When used in non-forking context, they can change global variables
* in the parent shell process. If forked, of course they cannot.
* For example, 'unset foo | whatever' will parse and run, but foo will
* still be set at the end. */
struct built_in_command {
const char *b_cmd;
int (*b_function)(char **argv) FAST_FUNC;
#if ENABLE_HUSH_HELP
const char *b_descr;
# define BLTIN(cmd, func, help) { cmd, func, help }
#else
# define BLTIN(cmd, func, help) { cmd, func }
#endif
};
static const struct built_in_command bltins1[] = {
BLTIN("." , builtin_source , "Run commands in a file"),
BLTIN(":" , builtin_true , NULL),
#if ENABLE_HUSH_JOB
BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
#endif
#if ENABLE_HUSH_LOOPS
BLTIN("break" , builtin_break , "Exit from a loop"),
#endif
BLTIN("cd" , builtin_cd , "Change directory"),
#if ENABLE_HUSH_LOOPS
BLTIN("continue" , builtin_continue, "Start new loop iteration"),
#endif
BLTIN("eval" , builtin_eval , "Construct and run shell command"),
BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
BLTIN("exit" , builtin_exit , "Exit"),
BLTIN("export" , builtin_export , "Set environment variables"),
#if ENABLE_HUSH_JOB
BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
#endif
#if ENABLE_HUSH_HELP
BLTIN("help" , builtin_help , NULL),
#endif
#if ENABLE_HUSH_JOB
BLTIN("jobs" , builtin_jobs , "List jobs"),
#endif
#if ENABLE_HUSH_LOCAL
BLTIN("local" , builtin_local , "Set local variables"),
#endif
#if HUSH_DEBUG
BLTIN("memleak" , builtin_memleak , NULL),
#endif
BLTIN("read" , builtin_read , "Input into variable"),
#if ENABLE_HUSH_FUNCTIONS
BLTIN("return" , builtin_return , "Return from a function"),
#endif
BLTIN("set" , builtin_set , "Set/unset positional parameters"),
BLTIN("shift" , builtin_shift , "Shift positional parameters"),
#if ENABLE_HUSH_BASH_COMPAT
BLTIN("source" , builtin_source , "Run commands in a file"),
#endif
BLTIN("trap" , builtin_trap , "Trap signals"),
BLTIN("type" , builtin_type , "Show command type"),
BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
BLTIN("umask" , builtin_umask , "Set file creation mask"),
BLTIN("unset" , builtin_unset , "Unset variables"),
BLTIN("wait" , builtin_wait , "Wait for process"),
};
/* For now, echo and test are unconditionally enabled.
* Maybe make it configurable? */
static const struct built_in_command bltins2[] = {
BLTIN("[" , builtin_test , NULL),
BLTIN("echo" , builtin_echo , NULL),
#if ENABLE_PRINTF
BLTIN("printf" , builtin_printf , NULL),
#endif
BLTIN("pwd" , builtin_pwd , NULL),
BLTIN("test" , builtin_test , NULL),
};
/* Debug printouts.
*/
#if HUSH_DEBUG
/* prevent disasters with G.debug_indent < 0 */
# define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
# define debug_enter() (G.debug_indent++)
# define debug_leave() (G.debug_indent--)
#else
# define indent() ((void)0)
# define debug_enter() ((void)0)
# define debug_leave() ((void)0)
#endif
#ifndef debug_printf
# define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_parse
# define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_exec
#define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_env
# define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_jobs
# define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
# define DEBUG_JOBS 1
#else
# define DEBUG_JOBS 0
#endif
#ifndef debug_printf_expand
# define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
# define DEBUG_EXPAND 1
#else
# define DEBUG_EXPAND 0
#endif
#ifndef debug_printf_varexp
# define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_glob
# define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
# define DEBUG_GLOB 1
#else
# define DEBUG_GLOB 0
#endif
#ifndef debug_printf_list
# define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_subst
# define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_clean
# define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
# define DEBUG_CLEAN 1
#else
# define DEBUG_CLEAN 0
#endif
#if DEBUG_EXPAND
static void debug_print_strings(const char *prefix, char **vv)
{
indent();
fdprintf(2, "%s:\n", prefix);
while (*vv)
fdprintf(2, " '%s'\n", *vv++);
}
#else
# define debug_print_strings(prefix, vv) ((void)0)
#endif
/* Leak hunting. Use hush_leaktool.sh for post-processing.
*/
#if LEAK_HUNTING
static void *xxmalloc(int lineno, size_t size)
{
void *ptr = xmalloc((size + 0xff) & ~0xff);
fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
return ptr;
}
static void *xxrealloc(int lineno, void *ptr, size_t size)
{
ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
return ptr;
}
static char *xxstrdup(int lineno, const char *str)
{
char *ptr = xstrdup(str);
fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
return ptr;
}
static void xxfree(void *ptr)
{
fdprintf(2, "free %p\n", ptr);
free(ptr);
}
# define xmalloc(s) xxmalloc(__LINE__, s)
# define xrealloc(p, s) xxrealloc(__LINE__, p, s)
# define xstrdup(s) xxstrdup(__LINE__, s)
# define free(p) xxfree(p)
#endif
/* Syntax and runtime errors. They always abort scripts.
* In interactive use they usually discard unparsed and/or unexecuted commands
* and return to the prompt.
* HUSH_DEBUG >= 2 prints line number in this file where it was detected.
*/
#if HUSH_DEBUG < 2
# define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
# define syntax_error(lineno, msg) syntax_error(msg)
# define syntax_error_at(lineno, msg) syntax_error_at(msg)
# define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
# define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
# define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
#endif
static void die_if_script(unsigned lineno, const char *fmt, ...)
{
va_list p;
#if HUSH_DEBUG >= 2
bb_error_msg("hush.c:%u", lineno);
#endif
va_start(p, fmt);
bb_verror_msg(fmt, p, NULL);
va_end(p);
if (!G_interactive_fd)
xfunc_die();
}
static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
{
if (msg)
bb_error_msg("syntax error: %s", msg);
else
bb_error_msg("syntax error");
}
static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
{
bb_error_msg("syntax error at '%s'", msg);
}
static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
{
bb_error_msg("syntax error: unterminated %s", s);
}
static void syntax_error_unterm_ch(unsigned lineno, char ch)
{
char msg[2] = { ch, '\0' };
syntax_error_unterm_str(lineno, msg);
}
static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
{
char msg[2];
msg[0] = ch;
msg[1] = '\0';
bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
}
#if HUSH_DEBUG < 2
# undef die_if_script
# undef syntax_error
# undef syntax_error_at
# undef syntax_error_unterm_ch
# undef syntax_error_unterm_str
# undef syntax_error_unexpected_ch
#else
# define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
# define syntax_error(msg) syntax_error(__LINE__, msg)
# define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
# define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
# define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
# define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
#endif
#if ENABLE_HUSH_INTERACTIVE
static void cmdedit_update_prompt(void);
#else
# define cmdedit_update_prompt() ((void)0)
#endif
/* Utility functions
*/
/* Replace each \x with x in place, return ptr past NUL. */
static char *unbackslash(char *src)
{
char *dst = src = strchrnul(src, '\\');
while (1) {
if (*src == '\\')
src++;
if ((*dst++ = *src++) == '\0')
break;
}
return dst;
}
static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
{
int i;
unsigned count1;
unsigned count2;
char **v;
v = strings;
count1 = 0;
if (v) {
while (*v) {
count1++;
v++;
}
}
count2 = 0;
v = add;
while (*v) {
count2++;
v++;
}
v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
v[count1 + count2] = NULL;
i = count2;
while (--i >= 0)
v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
return v;
}
#if LEAK_HUNTING
static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
{
char **ptr = add_strings_to_strings(strings, add, need_to_dup);
fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
return ptr;
}
#define add_strings_to_strings(strings, add, need_to_dup) \
xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
#endif
/* Note: takes ownership of "add" ptr (it is not strdup'ed) */
static char **add_string_to_strings(char **strings, char *add)
{
char *v[2];
v[0] = add;
v[1] = NULL;
return add_strings_to_strings(strings, v, /*dup:*/ 0);
}
#if LEAK_HUNTING
static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
{
char **ptr = add_string_to_strings(strings, add);
fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
return ptr;
}
#define add_string_to_strings(strings, add) \
xx_add_string_to_strings(__LINE__, strings, add)
#endif
static void free_strings(char **strings)
{
char **v;
if (!strings)
return;
v = strings;
while (*v) {
free(*v);
v++;
}
free(strings);
}
/* Helpers for setting new $n and restoring them back
*/
typedef struct save_arg_t {
char *sv_argv0;
char **sv_g_argv;
int sv_g_argc;
smallint sv_g_malloced;
} save_arg_t;
static void save_and_replace_G_args(save_arg_t *sv, char **argv)
{
int n;
sv->sv_argv0 = argv[0];
sv->sv_g_argv = G.global_argv;
sv->sv_g_argc = G.global_argc;
sv->sv_g_malloced = G.global_args_malloced;
argv[0] = G.global_argv[0]; /* retain $0 */
G.global_argv = argv;
G.global_args_malloced = 0;
n = 1;
while (*++argv)
n++;
G.global_argc = n;
}
static void restore_G_args(save_arg_t *sv, char **argv)
{
char **pp;
if (G.global_args_malloced) {
/* someone ran "set -- arg1 arg2 ...", undo */
pp = G.global_argv;
while (*++pp) /* note: does not free $0 */
free(*pp);
free(G.global_argv);
}
argv[0] = sv->sv_argv0;
G.global_argv = sv->sv_g_argv;
G.global_argc = sv->sv_g_argc;
G.global_args_malloced = sv->sv_g_malloced;
}
/* Basic theory of signal handling in shell
* ========================================
* This does not describe what hush does, rather, it is current understanding
* what it _should_ do. If it doesn't, it's a bug.
* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
*
* Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
* is finished or backgrounded. It is the same in interactive and
* non-interactive shells, and is the same regardless of whether
* a user trap handler is installed or a shell special one is in effect.
* ^C or ^Z from keyboard seems to execute "at once" because it usually
* backgrounds (i.e. stops) or kills all members of currently running
* pipe.
*
* Wait builtin in interruptible by signals for which user trap is set
* or by SIGINT in interactive shell.
*
* Trap handlers will execute even within trap handlers. (right?)
*
* User trap handlers are forgotten when subshell ("(cmd)") is entered,
* except for handlers set to '' (empty string).
*
* If job control is off, backgrounded commands ("cmd &")
* have SIGINT, SIGQUIT set to SIG_IGN.
*
* Commands which are run in command substitution ("`cmd`")
* have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
*
* Ordinary commands have signals set to SIG_IGN/DFL as inherited
* by the shell from its parent.
*
* Signals which differ from SIG_DFL action
* (note: child (i.e., [v]forked) shell is not an interactive shell):
*
* SIGQUIT: ignore
* SIGTERM (interactive): ignore
* SIGHUP (interactive):
* send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
* SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
* Note that ^Z is handled not by trapping SIGTSTP, but by seeing
* that all pipe members are stopped. Try this in bash:
* while :; do :; done - ^Z does not background it
* (while :; do :; done) - ^Z backgrounds it
* SIGINT (interactive): wait for last pipe, ignore the rest
* of the command line, show prompt. NB: ^C does not send SIGINT
* to interactive shell while shell is waiting for a pipe,
* since shell is bg'ed (is not in foreground process group).
* Example 1: this waits 5 sec, but does not execute ls:
* "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
* Example 2: this does not wait and does not execute ls:
* "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
* Example 3: this does not wait 5 sec, but executes ls:
* "sleep 5; ls -l" + press ^C
* Example 4: this does not wait and does not execute ls:
* "sleep 5 & wait; ls -l" + press ^C
*
* (What happens to signals which are IGN on shell start?)
* (What happens with signal mask on shell start?)
*
* Old implementation
* ==================
* We use in-kernel pending signal mask to determine which signals were sent.
* We block all signals which we don't want to take action immediately,
* i.e. we block all signals which need to have special handling as described
* above, and all signals which have traps set.
* After each pipe execution, we extract any pending signals via sigtimedwait()
* and act on them.
*
* unsigned special_sig_mask: a mask of such "special" signals
* sigset_t blocked_set: current blocked signal set
*
* "trap - SIGxxx":
* clear bit in blocked_set unless it is also in special_sig_mask
* "trap 'cmd' SIGxxx":
* set bit in blocked_set (even if 'cmd' is '')
* after [v]fork, if we plan to be a shell:
* unblock signals with special interactive handling
* (child shell is not interactive),
* unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
* after [v]fork, if we plan to exec:
* POSIX says fork clears pending signal mask in child - no need to clear it.
* Restore blocked signal set to one inherited by shell just prior to exec.
*
* Note: as a result, we do not use signal handlers much. The only uses
* are to count SIGCHLDs
* and to restore tty pgrp on signal-induced exit.
*
* Note 2 (compat):
* Standard says "When a subshell is entered, traps that are not being ignored
* are set to the default actions". bash interprets it so that traps which
* are set to '' (ignore) are NOT reset to defaults. We do the same.
*
* Problem: the above approach makes it unwieldy to catch signals while
* we are in read builtin, of while we read commands from stdin:
* masked signals are not visible!
*
* New implementation
* ==================
* We record each signal we are interested in by installing signal handler
* for them - a bit like emulating kernel pending signal mask in userspace.
* We are interested in: signals which need to have special handling
* as described above, and all signals which have traps set.
* Signals are rocorded in pending_set.
* After each pipe execution, we extract any pending signals
* and act on them.
*
* unsigned special_sig_mask: a mask of shell-special signals.
* unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
* char *traps[sig] if trap for sig is set (even if it's '').
* sigset_t pending_set: set of sigs we received.
*
* "trap - SIGxxx":
* if sig is in special_sig_mask, set handler back to:
* record_pending_signo, or to IGN if it's a tty stop signal
* if sig is in fatal_sig_mask, set handler back to sigexit.
* else: set handler back to SIG_DFL
* "trap 'cmd' SIGxxx":
* set handler to record_pending_signo.
* "trap '' SIGxxx":
* set handler to SIG_IGN.
* after [v]fork, if we plan to be a shell:
* set signals with special interactive handling to SIG_DFL
* (because child shell is not interactive),
* unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
* after [v]fork, if we plan to exec:
* POSIX says fork clears pending signal mask in child - no need to clear it.
*
* To make wait builtin interruptible, we handle SIGCHLD as special signal,
* otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
*
* Note (compat):
* Standard says "When a subshell is entered, traps that are not being ignored
* are set to the default actions". bash interprets it so that traps which
* are set to '' (ignore) are NOT reset to defaults. We do the same.
*/
enum {
SPECIAL_INTERACTIVE_SIGS = 0
| (1 << SIGTERM)
| (1 << SIGINT)
| (1 << SIGHUP)
,
SPECIAL_JOBSTOP_SIGS = 0
#if ENABLE_HUSH_JOB
| (1 << SIGTTIN)
| (1 << SIGTTOU)
| (1 << SIGTSTP)
#endif
,
};
static void record_pending_signo(int sig)
{
sigaddset(&G.pending_set, sig);
#if ENABLE_HUSH_FAST
if (sig == SIGCHLD) {
G.count_SIGCHLD++;
//bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
}
#endif
}
static sighandler_t install_sighandler(int sig, sighandler_t handler)
{
struct sigaction old_sa;
/* We could use signal() to install handlers... almost:
* except that we need to mask ALL signals while handlers run.
* I saw signal nesting in strace, race window isn't small.
* SA_RESTART is also needed, but in Linux, signal()
* sets SA_RESTART too.
*/
/* memset(&G.sa, 0, sizeof(G.sa)); - already done */
/* sigfillset(&G.sa.sa_mask); - already done */
/* G.sa.sa_flags = SA_RESTART; - already done */
G.sa.sa_handler = handler;
sigaction(sig, &G.sa, &old_sa);
return old_sa.sa_handler;
}
#if ENABLE_HUSH_JOB
/* After [v]fork, in child: do not restore tty pgrp on xfunc death */
# define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
/* After [v]fork, in parent: restore tty pgrp on xfunc death */
# define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
/* Restores tty foreground process group, and exits.
* May be called as signal handler for fatal signal
* (will resend signal to itself, producing correct exit state)
* or called directly with -EXITCODE.
* We also call it if xfunc is exiting. */
static void sigexit(int sig) NORETURN;
static void sigexit(int sig)
{
/* Careful: we can end up here after [v]fork. Do not restore
* tty pgrp then, only top-level shell process does that */
if (G_saved_tty_pgrp && getpid() == G.root_pid) {
/* Disable all signals: job control, SIGPIPE, etc.
* Mostly paranoid measure, to prevent infinite SIGTTOU.
*/
sigprocmask_allsigs(SIG_BLOCK);
tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
}
/* Not a signal, just exit */
if (sig <= 0)
_exit(- sig);
kill_myself_with_sig(sig); /* does not return */
}
#else
# define disable_restore_tty_pgrp_on_exit() ((void)0)
# define enable_restore_tty_pgrp_on_exit() ((void)0)
#endif
static sighandler_t pick_sighandler(unsigned sig)
{
sighandler_t handler = SIG_DFL;
if (sig < sizeof(unsigned)*8) {
unsigned sigmask = (1 << sig);
#if ENABLE_HUSH_JOB
/* is sig fatal? */
if (G_fatal_sig_mask & sigmask)
handler = sigexit;
else
#endif
/* sig has special handling? */
if (G.special_sig_mask & sigmask) {
handler = record_pending_signo;
/* TTIN/TTOU/TSTP can't be set to record_pending_signo
* in order to ignore them: they will be raised
* in an endless loop when we try to do some
* terminal ioctls! We do have to _ignore_ these.
*/
if (SPECIAL_JOBSTOP_SIGS & sigmask)
handler = SIG_IGN;
}
}
return handler;
}
/* Restores tty foreground process group, and exits. */
static void hush_exit(int exitcode) NORETURN;
static void hush_exit(int exitcode)
{
#if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
save_history(G.line_input_state);
#endif
fflush_all();
if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
char *argv[3];
/* argv[0] is unused */
argv[1] = G.traps[0];
argv[2] = NULL;
G.exiting = 1; /* prevent EXIT trap recursion */
/* Note: G.traps[0] is not cleared!
* "trap" will still show it, if executed
* in the handler */
builtin_eval(argv);
}
#if ENABLE_FEATURE_CLEAN_UP
{
struct variable *cur_var;
if (G.cwd != bb_msg_unknown)
free((char*)G.cwd);
cur_var = G.top_var;
while (cur_var) {
struct variable *tmp = cur_var;
if (!cur_var->max_len)
free(cur_var->varstr);
cur_var = cur_var->next;
free(tmp);
}
}
#endif
#if ENABLE_HUSH_JOB
fflush_all();
sigexit(- (exitcode & 0xff));
#else
exit(exitcode);
#endif
}
//TODO: return a mask of ALL handled sigs?
static int check_and_run_traps(void)
{
int last_sig = 0;
while (1) {
int sig;
if (sigisemptyset(&G.pending_set))
break;
sig = 0;
do {
sig++;
if (sigismember(&G.pending_set, sig)) {
sigdelset(&G.pending_set, sig);
goto got_sig;
}
} while (sig < NSIG);
break;
got_sig:
if (G.traps && G.traps[sig]) {
if (G.traps[sig][0]) {
/* We have user-defined handler */
smalluint save_rcode;
char *argv[3];
/* argv[0] is unused */
argv[1] = G.traps[sig];
argv[2] = NULL;
save_rcode = G.last_exitcode;
builtin_eval(argv);
G.last_exitcode = save_rcode;
last_sig = sig;
} /* else: "" trap, ignoring signal */
continue;
}
/* not a trap: special action */
switch (sig) {
case SIGINT:
/* Builtin was ^C'ed, make it look prettier: */
bb_putchar('\n');
G.flag_SIGINT = 1;
last_sig = sig;
break;
#if ENABLE_HUSH_JOB
case SIGHUP: {
struct pipe *job;
/* bash is observed to signal whole process groups,
* not individual processes */
for (job = G.job_list; job; job = job->next) {
if (job->pgrp <= 0)
continue;
debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
if (kill(- job->pgrp, SIGHUP) == 0)
kill(- job->pgrp, SIGCONT);
}
sigexit(SIGHUP);
}
#endif
#if ENABLE_HUSH_FAST
case SIGCHLD:
G.count_SIGCHLD++;
//bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
/* Note:
* We dont do 'last_sig = sig' here -> NOT returning this sig.
* This simplifies wait builtin a bit.
*/
break;
#endif
default: /* ignored: */
/* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
/* Note:
* We dont do 'last_sig = sig' here -> NOT returning this sig.
* Example: wait is not interrupted by TERM
* in interactive shell, because TERM is ignored.
*/
break;
}
}
return last_sig;
}
static const char *get_cwd(int force)
{
if (force || G.cwd == NULL) {
/* xrealloc_getcwd_or_warn(arg) calls free(arg),
* we must not try to free(bb_msg_unknown) */
if (G.cwd == bb_msg_unknown)
G.cwd = NULL;
G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
if (!G.cwd)
G.cwd = bb_msg_unknown;
}
return G.cwd;
}
/*
* Shell and environment variable support
*/
static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
{
struct variable **pp;
struct variable *cur;
pp = &G.top_var;
while ((cur = *pp) != NULL) {
if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
return pp;
pp = &cur->next;
}
return NULL;
}
static const char* FAST_FUNC get_local_var_value(const char *name)
{
struct variable **vpp;
unsigned len = strlen(name);
if (G.expanded_assignments) {
char **cpp = G.expanded_assignments;
while (*cpp) {
char *cp = *cpp;
if (strncmp(cp, name, len) == 0 && cp[len] == '=')
return cp + len + 1;
cpp++;
}
}
vpp = get_ptr_to_local_var(name, len);
if (vpp)
return (*vpp)->varstr + len + 1;
if (strcmp(name, "PPID") == 0)
return utoa(G.root_ppid);
// bash compat: UID? EUID?
#if ENABLE_HUSH_RANDOM_SUPPORT
if (strcmp(name, "RANDOM") == 0)
return utoa(next_random(&G.random_gen));
#endif
return NULL;
}
/* str holds "NAME=VAL" and is expected to be malloced.
* We take ownership of it.
* flg_export:
* 0: do not change export flag
* (if creating new variable, flag will be 0)
* 1: set export flag and putenv the variable
* -1: clear export flag and unsetenv the variable
* flg_read_only is set only when we handle -R var=val
*/
#if !BB_MMU && ENABLE_HUSH_LOCAL
/* all params are used */
#elif BB_MMU && ENABLE_HUSH_LOCAL
#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
set_local_var(str, flg_export, local_lvl)
#elif BB_MMU && !ENABLE_HUSH_LOCAL
#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
set_local_var(str, flg_export)
#elif !BB_MMU && !ENABLE_HUSH_LOCAL
#define set_local_var(str, flg_export, local_lvl, flg_read_only) \
set_local_var(str, flg_export, flg_read_only)
#endif
static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
{
struct variable **var_pp;
struct variable *cur;
char *eq_sign;
int name_len;
eq_sign = strchr(str, '=');
if (!eq_sign) { /* not expected to ever happen? */
free(str);
return -1;
}
name_len = eq_sign - str + 1; /* including '=' */
var_pp = &G.top_var;
while ((cur = *var_pp) != NULL) {
if (strncmp(cur->varstr, str, name_len) != 0) {
var_pp = &cur->next;
continue;
}
/* We found an existing var with this name */
if (cur->flg_read_only) {
#if !BB_MMU
if (!flg_read_only)
#endif
bb_error_msg("%s: readonly variable", str);
free(str);
return -1;
}
if (flg_export == -1) { // "&& cur->flg_export" ?
debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
*eq_sign = '\0';
unsetenv(str);
*eq_sign = '=';
}
#if ENABLE_HUSH_LOCAL
if (cur->func_nest_level < local_lvl) {
/* New variable is declared as local,
* and existing one is global, or local
* from enclosing function.
* Remove and save old one: */
*var_pp = cur->next;
cur->next = *G.shadowed_vars_pp;
*G.shadowed_vars_pp = cur;
/* bash 3.2.33(1) and exported vars:
* # export z=z
* # f() { local z=a; env | grep ^z; }
* # f
* z=a
* # env | grep ^z
* z=z
*/
if (cur->flg_export)
flg_export = 1;
break;
}
#endif
if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
free_and_exp:
free(str);
goto exp;
}
if (cur->max_len != 0) {
if (cur->max_len >= strlen(str)) {
/* This one is from startup env, reuse space */
strcpy(cur->varstr, str);
goto free_and_exp;
}
} else {
/* max_len == 0 signifies "malloced" var, which we can
* (and has to) free */
free(cur->varstr);
}
cur->max_len = 0;
goto set_str_and_exp;
}
/* Not found - create new variable struct */
cur = xzalloc(sizeof(*cur));
#if ENABLE_HUSH_LOCAL
cur->func_nest_level = local_lvl;
#endif
cur->next = *var_pp;
*var_pp = cur;
set_str_and_exp:
cur->varstr = str;
#if !BB_MMU
cur->flg_read_only = flg_read_only;
#endif
exp:
if (flg_export == 1)
cur->flg_export = 1;
if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
cmdedit_update_prompt();
if (cur->flg_export) {
if (flg_export == -1) {
cur->flg_export = 0;
/* unsetenv was already done */
} else {
debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
return putenv(cur->varstr);
}
}
return 0;
}
/* Used at startup and after each cd */
static void set_pwd_var(int exp)
{
set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
/*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
}
static int unset_local_var_len(const char *name, int name_len)
{
struct variable *cur;
struct variable **var_pp;
if (!name)
return EXIT_SUCCESS;
var_pp = &G.top_var;
while ((cur = *var_pp) != NULL) {
if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
if (cur->flg_read_only) {
bb_error_msg("%s: readonly variable", name);
return EXIT_FAILURE;
}
*var_pp = cur->next;
debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
bb_unsetenv(cur->varstr);
if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
cmdedit_update_prompt();
if (!cur->max_len)
free(cur->varstr);
free(cur);
return EXIT_SUCCESS;
}
var_pp = &cur->next;
}
return EXIT_SUCCESS;
}
static int unset_local_var(const char *name)
{
return unset_local_var_len(name, strlen(name));
}
static void unset_vars(char **strings)
{
char **v;
if (!strings)
return;
v = strings;
while (*v) {
const char *eq = strchrnul(*v, '=');
unset_local_var_len(*v, (int)(eq - *v));
v++;
}
free(strings);
}
static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
{
char *var = xasprintf("%s=%s", name, val);
set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
}
/*
* Helpers for "var1=val1 var2=val2 cmd" feature
*/
static void add_vars(struct variable *var)
{
struct variable *next;
while (var) {
next = var->next;
var->next = G.top_var;
G.top_var = var;
if (var->flg_export) {
debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
putenv(var->varstr);
} else {
debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
}
var = next;
}
}
static struct variable *set_vars_and_save_old(char **strings)
{
char **s;
struct variable *old = NULL;
if (!strings)
return old;
s = strings;
while (*s) {
struct variable *var_p;
struct variable **var_pp;
char *eq;
eq = strchr(*s, '=');
if (eq) {
var_pp = get_ptr_to_local_var(*s, eq - *s);
if (var_pp) {
/* Remove variable from global linked list */
var_p = *var_pp;
debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
*var_pp = var_p->next;
/* Add it to returned list */
var_p->next = old;
old = var_p;
}
set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
}
s++;
}
return old;
}
/*
* in_str support
*/
static int FAST_FUNC static_get(struct in_str *i)
{
int ch = *i->p;
if (ch != '\0') {
i->p++;
i->last_char = ch;
return ch;
}
return EOF;
}
static int FAST_FUNC static_peek(struct in_str *i)
{
return *i->p;
}
#if ENABLE_HUSH_INTERACTIVE
static void cmdedit_update_prompt(void)
{
if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
G.PS1 = get_local_var_value("PS1");
if (G.PS1 == NULL)
G.PS1 = "\\w \\$ ";
G.PS2 = get_local_var_value("PS2");
} else {
G.PS1 = NULL;
}
if (G.PS2 == NULL)
G.PS2 = "> ";
}
static const char *setup_prompt_string(int promptmode)
{
const char *prompt_str;
debug_printf("setup_prompt_string %d ", promptmode);
if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
/* Set up the prompt */
if (promptmode == 0) { /* PS1 */
free((char*)G.PS1);
/* bash uses $PWD value, even if it is set by user.
* It uses current dir only if PWD is unset.
* We always use current dir. */
G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
prompt_str = G.PS1;
} else
prompt_str = G.PS2;
} else
prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
debug_printf("result '%s'\n", prompt_str);
return prompt_str;
}
static void get_user_input(struct in_str *i)
{
int r;
const char *prompt_str;
prompt_str = setup_prompt_string(i->promptmode);
# if ENABLE_FEATURE_EDITING
/* Enable command line editing only while a command line
* is actually being read */
do {
/* Unicode support should be activated even if LANG is set
* _during_ shell execution, not only if it was set when
* shell was started. Therefore, re-check LANG every time:
*/
reinit_unicode(get_local_var_value("LANG"));
G.flag_SIGINT = 0;
/* buglet: SIGINT will not make new prompt to appear _at once_,
* only after <Enter>. (^C will work) */
r = read_line_input(G.line_input_state, prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, /*timeout*/ -1);
/* catch *SIGINT* etc (^C is handled by read_line_input) */
check_and_run_traps();
} while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
i->eof_flag = (r < 0);
if (i->eof_flag) { /* EOF/error detected */
G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
G.user_input_buf[1] = '\0';
}
# else
do {
G.flag_SIGINT = 0;
if (i->last_char == '\0' || i->last_char == '\n') {
/* Why check_and_run_traps here? Try this interactively:
* $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
* $ <[enter], repeatedly...>
* Without check_and_run_traps, handler never runs.
*/
check_and_run_traps();
fputs(prompt_str, stdout);
}
fflush_all();
G.user_input_buf[0] = r = fgetc(i->file);
/*G.user_input_buf[1] = '\0'; - already is and never changed */
} while (G.flag_SIGINT);
i->eof_flag = (r == EOF);
# endif
i->p = G.user_input_buf;
}
#endif /* INTERACTIVE */
/* This is the magic location that prints prompts
* and gets data back from the user */
static int FAST_FUNC file_get(struct in_str *i)
{
int ch;
/* If there is data waiting, eat it up */
if (i->p && *i->p) {
#if ENABLE_HUSH_INTERACTIVE
take_cached:
#endif
ch = *i->p++;
if (i->eof_flag && !*i->p)
ch = EOF;
/* note: ch is never NUL */
} else {
/* need to double check i->file because we might be doing something
* more complicated by now, like sourcing or substituting. */
#if ENABLE_HUSH_INTERACTIVE
if (G_interactive_fd && i->file == stdin) {
do {
get_user_input(i);
} while (!*i->p); /* need non-empty line */
i->promptmode = 1; /* PS2 */
goto take_cached;
}
#endif
do ch = fgetc(i->file); while (ch == '\0');
}
debug_printf("file_get: got '%c' %d\n", ch, ch);
i->last_char = ch;
return ch;
}
/* All callers guarantee this routine will never
* be used right after a newline, so prompting is not needed.
*/
static int FAST_FUNC file_peek(struct in_str *i)
{
int ch;
if (i->p && *i->p) {
if (i->eof_flag && !i->p[1])
return EOF;
return *i->p;
/* note: ch is never NUL */
}
do ch = fgetc(i->file); while (ch == '\0');
i->eof_flag = (ch == EOF);
i->peek_buf[0] = ch;
i->peek_buf[1] = '\0';
i->p = i->peek_buf;
debug_printf("file_peek: got '%c' %d\n", ch, ch);
return ch;
}
static void setup_file_in_str(struct in_str *i, FILE *f)
{
memset(i, 0, sizeof(*i));
i->peek = file_peek;
i->get = file_get;
/* i->promptmode = 0; - PS1 (memset did it) */
i->file = f;
/* i->p = NULL; */
}
static void setup_string_in_str(struct in_str *i, const char *s)
{
memset(i, 0, sizeof(*i));
i->peek = static_peek;
i->get = static_get;
/* i->promptmode = 0; - PS1 (memset did it) */
i->p = s;
/* i->eof_flag = 0; */
}
/*
* o_string support
*/
#define B_CHUNK (32 * sizeof(char*))
static void o_reset_to_empty_unquoted(o_string *o)
{
o->length = 0;
o->has_quoted_part = 0;
if (o->data)
o->data[0] = '\0';
}
static void o_free(o_string *o)
{
free(o->data);
memset(o, 0, sizeof(*o));
}
static ALWAYS_INLINE void o_free_unsafe(o_string *o)
{
free(o->data);
}
static void o_grow_by(o_string *o, int len)
{
if (o->length + len > o->maxlen) {
o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
o->data = xrealloc(o->data, 1 + o->maxlen);
}
}
static void o_addchr(o_string *o, int ch)
{
debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
o_grow_by(o, 1);
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
static void o_addblock(o_string *o, const char *str, int len)
{
o_grow_by(o, len);
memcpy(&o->data[o->length], str, len);
o->length += len;
o->data[o->length] = '\0';
}
static void o_addstr(o_string *o, const char *str)
{
o_addblock(o, str, strlen(str));
}
#if !BB_MMU
static void nommu_addchr(o_string *o, int ch)
{
if (o)
o_addchr(o, ch);
}
#else
# define nommu_addchr(o, str) ((void)0)
#endif
static void o_addstr_with_NUL(o_string *o, const char *str)
{
o_addblock(o, str, strlen(str) + 1);
}
/*
* HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
* Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
* Apparently, on unquoted $v bash still does globbing
* ("v='*.txt'; echo $v" prints all .txt files),
* but NOT brace expansion! Thus, there should be TWO independent
* quoting mechanisms on $v expansion side: one protects
* $v from brace expansion, and other additionally protects "$v" against globbing.
* We have only second one.
*/
#if ENABLE_HUSH_BRACE_EXPANSION
# define MAYBE_BRACES "{}"
#else
# define MAYBE_BRACES ""
#endif
/* My analysis of quoting semantics tells me that state information
* is associated with a destination, not a source.
*/
static void o_addqchr(o_string *o, int ch)
{
int sz = 1;
char *found = strchr("*?[\\" MAYBE_BRACES, ch);
if (found)
sz++;
o_grow_by(o, sz);
if (found) {
o->data[o->length] = '\\';
o->length++;
}
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
static void o_addQchr(o_string *o, int ch)
{
int sz = 1;
if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
&& strchr("*?[\\" MAYBE_BRACES, ch)
) {
sz++;
o->data[o->length] = '\\';
o->length++;
}
o_grow_by(o, sz);
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
static void o_addqblock(o_string *o, const char *str, int len)
{
while (len) {
char ch;
int sz;
int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
if (ordinary_cnt > len) /* paranoia */
ordinary_cnt = len;
o_addblock(o, str, ordinary_cnt);
if (ordinary_cnt == len)
return; /* NUL is already added by o_addblock */
str += ordinary_cnt;
len -= ordinary_cnt + 1; /* we are processing + 1 char below */
ch = *str++;
sz = 1;
if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
sz++;
o->data[o->length] = '\\';
o->length++;
}
o_grow_by(o, sz);
o->data[o->length] = ch;
o->length++;
}
o->data[o->length] = '\0';
}
static void o_addQblock(o_string *o, const char *str, int len)
{
if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
o_addblock(o, str, len);
return;
}
o_addqblock(o, str, len);
}
static void o_addQstr(o_string *o, const char *str)
{
o_addQblock(o, str, strlen(str));
}
/* A special kind of o_string for $VAR and `cmd` expansion.
* It contains char* list[] at the beginning, which is grown in 16 element
* increments. Actual string data starts at the next multiple of 16 * (char*).
* list[i] contains an INDEX (int!) into this string data.
* It means that if list[] needs to grow, data needs to be moved higher up
* but list[i]'s need not be modified.
* NB: remembering how many list[i]'s you have there is crucial.
* o_finalize_list() operation post-processes this structure - calculates
* and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
*/
#if DEBUG_EXPAND || DEBUG_GLOB
static void debug_print_list(const char *prefix, o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
int i = 0;
indent();
fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
prefix, list, n, string_start, o->length, o->maxlen,
!!(o->o_expflags & EXP_FLAG_GLOB),
o->has_quoted_part,
!!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
while (i < n) {
indent();
fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
o->data + (int)(uintptr_t)list[i] + string_start,
o->data + (int)(uintptr_t)list[i] + string_start);
i++;
}
if (n) {
const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
indent();
fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
}
}
#else
# define debug_print_list(prefix, o, n) ((void)0)
#endif
/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
* in list[n] so that it points past last stored byte so far.
* It returns n+1. */
static int o_save_ptr_helper(o_string *o, int n)
{
char **list = (char**)o->data;
int string_start;
int string_len;
if (!o->has_empty_slot) {
string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
string_len = o->length - string_start;
if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
/* list[n] points to string_start, make space for 16 more pointers */
o->maxlen += 0x10 * sizeof(list[0]);
o->data = xrealloc(o->data, o->maxlen + 1);
list = (char**)o->data;
memmove(list + n + 0x10, list + n, string_len);
o->length += 0x10 * sizeof(list[0]);
} else {
debug_printf_list("list[%d]=%d string_start=%d\n",
n, string_len, string_start);
}
} else {
/* We have empty slot at list[n], reuse without growth */
string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
string_len = o->length - string_start;
debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
n, string_len, string_start);
o->has_empty_slot = 0;
}
o->has_quoted_part = 0;
list[n] = (char*)(uintptr_t)string_len;
return n + 1;
}
/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
static int o_get_last_ptr(o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
return ((int)(uintptr_t)list[n-1]) + string_start;
}
#if ENABLE_HUSH_BRACE_EXPANSION
/* There in a GNU extension, GLOB_BRACE, but it is not usable:
* first, it processes even {a} (no commas), second,
* I didn't manage to make it return strings when they don't match
* existing files. Need to re-implement it.
*/
/* Helper */
static int glob_needed(const char *s)
{
while (*s) {
if (*s == '\\') {
if (!s[1])
return 0;
s += 2;
continue;
}
if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
return 1;
s++;
}
return 0;
}
/* Return pointer to next closing brace or to comma */
static const char *next_brace_sub(const char *cp)
{
unsigned depth = 0;
cp++;
while (*cp != '\0') {
if (*cp == '\\') {
if (*++cp == '\0')
break;
cp++;
continue;
}
if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
break;
if (*cp++ == '{')
depth++;
}
return *cp != '\0' ? cp : NULL;
}
/* Recursive brace globber. Note: may garble pattern[]. */
static int glob_brace(char *pattern, o_string *o, int n)
{
char *new_pattern_buf;
const char *begin;
const char *next;
const char *rest;
const char *p;
size_t rest_len;
debug_printf_glob("glob_brace('%s')\n", pattern);
begin = pattern;
while (1) {
if (*begin == '\0')
goto simple_glob;
if (*begin == '{') {
/* Find the first sub-pattern and at the same time
* find the rest after the closing brace */
next = next_brace_sub(begin);
if (next == NULL) {
/* An illegal expression */
goto simple_glob;
}
if (*next == '}') {
/* "{abc}" with no commas - illegal
* brace expr, disregard and skip it */
begin = next + 1;
continue;
}
break;
}
if (*begin == '\\' && begin[1] != '\0')
begin++;
begin++;
}
debug_printf_glob("begin:%s\n", begin);
debug_printf_glob("next:%s\n", next);
/* Now find the end of the whole brace expression */
rest = next;
while (*rest != '}') {
rest = next_brace_sub(rest);
if (rest == NULL) {
/* An illegal expression */
goto simple_glob;
}
debug_printf_glob("rest:%s\n", rest);
}
rest_len = strlen(++rest) + 1;
/* We are sure the brace expression is well-formed */
/* Allocate working buffer large enough for our work */
new_pattern_buf = xmalloc(strlen(pattern));
/* We have a brace expression. BEGIN points to the opening {,
* NEXT points past the terminator of the first element, and REST
* points past the final }. We will accumulate result names from
* recursive runs for each brace alternative in the buffer using
* GLOB_APPEND. */
p = begin + 1;
while (1) {
/* Construct the new glob expression */
memcpy(
mempcpy(
mempcpy(new_pattern_buf,
/* We know the prefix for all sub-patterns */
pattern, begin - pattern),
p, next - p),
rest, rest_len);
/* Note: glob_brace() may garble new_pattern_buf[].
* That's why we re-copy prefix every time (1st memcpy above).
*/
n = glob_brace(new_pattern_buf, o, n);
if (*next == '}') {
/* We saw the last entry */
break;
}
p = next + 1;
next = next_brace_sub(next);
}
free(new_pattern_buf);
return n;
simple_glob:
{
int gr;
glob_t globdata;
memset(&globdata, 0, sizeof(globdata));
gr = glob(pattern, 0, NULL, &globdata);
debug_printf_glob("glob('%s'):%d\n", pattern, gr);
if (gr != 0) {
if (gr == GLOB_NOMATCH) {
globfree(&globdata);
/* NB: garbles parameter */
unbackslash(pattern);
o_addstr_with_NUL(o, pattern);
debug_printf_glob("glob pattern '%s' is literal\n", pattern);
return o_save_ptr_helper(o, n);
}
if (gr == GLOB_NOSPACE)
bb_error_msg_and_die(bb_msg_memory_exhausted);
/* GLOB_ABORTED? Only happens with GLOB_ERR flag,
* but we didn't specify it. Paranoia again. */
bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
}
if (globdata.gl_pathv && globdata.gl_pathv[0]) {
char **argv = globdata.gl_pathv;
while (1) {
o_addstr_with_NUL(o, *argv);
n = o_save_ptr_helper(o, n);
argv++;
if (!*argv)
break;
}
}
globfree(&globdata);
}
return n;
}
/* Performs globbing on last list[],
* saving each result as a new list[].
*/
static int perform_glob(o_string *o, int n)
{
char *pattern, *copy;
debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
if (!o->data)
return o_save_ptr_helper(o, n);
pattern = o->data + o_get_last_ptr(o, n);
debug_printf_glob("glob pattern '%s'\n", pattern);
if (!glob_needed(pattern)) {
/* unbackslash last string in o in place, fix length */
o->length = unbackslash(pattern) - o->data;
debug_printf_glob("glob pattern '%s' is literal\n", pattern);
return o_save_ptr_helper(o, n);
}
copy = xstrdup(pattern);
/* "forget" pattern in o */
o->length = pattern - o->data;
n = glob_brace(copy, o, n);
free(copy);
if (DEBUG_GLOB)
debug_print_list("perform_glob returning", o, n);
return n;
}
#else /* !HUSH_BRACE_EXPANSION */
/* Helper */
static int glob_needed(const char *s)
{
while (*s) {
if (*s == '\\') {
if (!s[1])
return 0;
s += 2;
continue;
}
if (*s == '*' || *s == '[' || *s == '?')
return 1;
s++;
}
return 0;
}
/* Performs globbing on last list[],
* saving each result as a new list[].
*/
static int perform_glob(o_string *o, int n)
{
glob_t globdata;
int gr;
char *pattern;
debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
if (!o->data)
return o_save_ptr_helper(o, n);
pattern = o->data + o_get_last_ptr(o, n);
debug_printf_glob("glob pattern '%s'\n", pattern);
if (!glob_needed(pattern)) {
literal:
/* unbackslash last string in o in place, fix length */
o->length = unbackslash(pattern) - o->data;
debug_printf_glob("glob pattern '%s' is literal\n", pattern);
return o_save_ptr_helper(o, n);
}
memset(&globdata, 0, sizeof(globdata));
/* Can't use GLOB_NOCHECK: it does not unescape the string.
* If we glob "*.\*" and don't find anything, we need
* to fall back to using literal "*.*", but GLOB_NOCHECK
* will return "*.\*"!
*/
gr = glob(pattern, 0, NULL, &globdata);
debug_printf_glob("glob('%s'):%d\n", pattern, gr);
if (gr != 0) {
if (gr == GLOB_NOMATCH) {
globfree(&globdata);
goto literal;
}
if (gr == GLOB_NOSPACE)
bb_error_msg_and_die(bb_msg_memory_exhausted);
/* GLOB_ABORTED? Only happens with GLOB_ERR flag,
* but we didn't specify it. Paranoia again. */
bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
}
if (globdata.gl_pathv && globdata.gl_pathv[0]) {
char **argv = globdata.gl_pathv;
/* "forget" pattern in o */
o->length = pattern - o->data;
while (1) {
o_addstr_with_NUL(o, *argv);
n = o_save_ptr_helper(o, n);
argv++;
if (!*argv)
break;
}
}
globfree(&globdata);
if (DEBUG_GLOB)
debug_print_list("perform_glob returning", o, n);
return n;
}
#endif /* !HUSH_BRACE_EXPANSION */
/* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
* Otherwise, just finish current list[] and start new */
static int o_save_ptr(o_string *o, int n)
{
if (o->o_expflags & EXP_FLAG_GLOB) {
/* If o->has_empty_slot, list[n] was already globbed
* (if it was requested back then when it was filled)
* so don't do that again! */
if (!o->has_empty_slot)
return perform_glob(o, n); /* o_save_ptr_helper is inside */
}
return o_save_ptr_helper(o, n);
}
/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
static char **o_finalize_list(o_string *o, int n)
{
char **list;
int string_start;
n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
if (DEBUG_EXPAND)
debug_print_list("finalized", o, n);
debug_printf_expand("finalized n:%d\n", n);
list = (char**)o->data;
string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
list[--n] = NULL;
while (n) {
n--;
list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
}
return list;
}
static void free_pipe_list(struct pipe *pi);
/* Returns pi->next - next pipe in the list */
static struct pipe *free_pipe(struct pipe *pi)
{
struct pipe *next;
int i;
debug_printf_clean("free_pipe (pid %d)\n", getpid());
for (i = 0; i < pi->num_cmds; i++) {
struct command *command;
struct redir_struct *r, *rnext;
command = &pi->cmds[i];
debug_printf_clean(" command %d:\n", i);
if (command->argv) {
if (DEBUG_CLEAN) {
int a;
char **p;
for (a = 0, p = command->argv; *p; a++, p++) {
debug_printf_clean(" argv[%d] = %s\n", a, *p);
}
}
free_strings(command->argv);
//command->argv = NULL;
}
/* not "else if": on syntax error, we may have both! */
if (command->group) {
debug_printf_clean(" begin group (cmd_type:%d)\n",
command->cmd_type);
free_pipe_list(command->group);
debug_printf_clean(" end group\n");
//command->group = NULL;
}
/* else is crucial here.
* If group != NULL, child_func is meaningless */
#if ENABLE_HUSH_FUNCTIONS
else if (command->child_func) {
debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
command->child_func->parent_cmd = NULL;
}
#endif
#if !BB_MMU
free(command->group_as_string);
//command->group_as_string = NULL;
#endif
for (r = command->redirects; r; r = rnext) {
debug_printf_clean(" redirect %d%s",
r->rd_fd, redir_table[r->rd_type].descrip);
/* guard against the case >$FOO, where foo is unset or blank */
if (r->rd_filename) {
debug_printf_clean(" fname:'%s'\n", r->rd_filename);
free(r->rd_filename);
//r->rd_filename = NULL;
}
debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
rnext = r->next;
free(r);
}
//command->redirects = NULL;
}
free(pi->cmds); /* children are an array, they get freed all at once */
//pi->cmds = NULL;
#if ENABLE_HUSH_JOB
free(pi->cmdtext);
//pi->cmdtext = NULL;
#endif
next = pi->next;
free(pi);
return next;
}
static void free_pipe_list(struct pipe *pi)
{
while (pi) {
#if HAS_KEYWORDS
debug_printf_clean("pipe reserved word %d\n", pi->res_word);
#endif
debug_printf_clean("pipe followup code %d\n", pi->followup);
pi = free_pipe(pi);
}
}
/*** Parsing routines ***/
#ifndef debug_print_tree
static void debug_print_tree(struct pipe *pi, int lvl)
{
static const char *const PIPE[] = {
[PIPE_SEQ] = "SEQ",
[PIPE_AND] = "AND",
[PIPE_OR ] = "OR" ,
[PIPE_BG ] = "BG" ,
};
static const char *RES[] = {
[RES_NONE ] = "NONE" ,
# if ENABLE_HUSH_IF
[RES_IF ] = "IF" ,
[RES_THEN ] = "THEN" ,
[RES_ELIF ] = "ELIF" ,
[RES_ELSE ] = "ELSE" ,
[RES_FI ] = "FI" ,
# endif
# if ENABLE_HUSH_LOOPS
[RES_FOR ] = "FOR" ,
[RES_WHILE] = "WHILE",
[RES_UNTIL] = "UNTIL",
[RES_DO ] = "DO" ,
[RES_DONE ] = "DONE" ,
# endif
# if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
[RES_IN ] = "IN" ,
# endif
# if ENABLE_HUSH_CASE
[RES_CASE ] = "CASE" ,
[RES_CASE_IN ] = "CASE_IN" ,
[RES_MATCH] = "MATCH",
[RES_CASE_BODY] = "CASE_BODY",
[RES_ESAC ] = "ESAC" ,
# endif
[RES_XXXX ] = "XXXX" ,
[RES_SNTX ] = "SNTX" ,
};
static const char *const CMDTYPE[] = {
"{}",
"()",
"[noglob]",
# if ENABLE_HUSH_FUNCTIONS
"func()",
# endif
};
int pin, prn;
pin = 0;
while (pi) {
fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
prn = 0;
while (prn < pi->num_cmds) {
struct command *command = &pi->cmds[prn];
char **argv = command->argv;
fdprintf(2, "%*s cmd %d assignment_cnt:%d",
lvl*2, "", prn,
command->assignment_cnt);
if (command->group) {
fdprintf(2, " group %s: (argv=%p)%s%s\n",
CMDTYPE[command->cmd_type],
argv
# if !BB_MMU
, " group_as_string:", command->group_as_string
# else
, "", ""
# endif
);
debug_print_tree(command->group, lvl+1);
prn++;
continue;
}
if (argv) while (*argv) {
fdprintf(2, " '%s'", *argv);
argv++;
}
fdprintf(2, "\n");
prn++;
}
pi = pi->next;
pin++;
}
}
#endif /* debug_print_tree */
static struct pipe *new_pipe(void)
{
struct pipe *pi;
pi = xzalloc(sizeof(struct pipe));
/*pi->followup = 0; - deliberately invalid value */
/*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
return pi;
}
/* Command (member of a pipe) is complete, or we start a new pipe
* if ctx->command is NULL.
* No errors possible here.
*/
static int done_command(struct parse_context *ctx)
{
/* The command is really already in the pipe structure, so
* advance the pipe counter and make a new, null command. */
struct pipe *pi = ctx->pipe;
struct command *command = ctx->command;
if (command) {
if (IS_NULL_CMD(command)) {
debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
goto clear_and_ret;
}
pi->num_cmds++;
debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
//debug_print_tree(ctx->list_head, 20);
} else {
debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
}
/* Only real trickiness here is that the uncommitted
* command structure is not counted in pi->num_cmds. */
pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
ctx->command = command = &pi->cmds[pi->num_cmds];
clear_and_ret:
memset(command, 0, sizeof(*command));
return pi->num_cmds; /* used only for 0/nonzero check */
}
static void done_pipe(struct parse_context *ctx, pipe_style type)
{
int not_null;
debug_printf_parse("done_pipe entered, followup %d\n", type);
/* Close previous command */
not_null = done_command(ctx);
ctx->pipe->followup = type;
#if HAS_KEYWORDS
ctx->pipe->pi_inverted = ctx->ctx_inverted;
ctx->ctx_inverted = 0;
ctx->pipe->res_word = ctx->ctx_res_w;
#endif
/* Without this check, even just <enter> on command line generates
* tree of three NOPs (!). Which is harmless but annoying.
* IOW: it is safe to do it unconditionally. */
if (not_null
#if ENABLE_HUSH_IF
|| ctx->ctx_res_w == RES_FI
#endif
#if ENABLE_HUSH_LOOPS
|| ctx->ctx_res_w == RES_DONE
|| ctx->ctx_res_w == RES_FOR
|| ctx->ctx_res_w == RES_IN
#endif
#if ENABLE_HUSH_CASE
|| ctx->ctx_res_w == RES_ESAC
#endif
) {
struct pipe *new_p;
debug_printf_parse("done_pipe: adding new pipe: "
"not_null:%d ctx->ctx_res_w:%d\n",
not_null, ctx->ctx_res_w);
new_p = new_pipe();
ctx->pipe->next = new_p;
ctx->pipe = new_p;
/* RES_THEN, RES_DO etc are "sticky" -
* they remain set for pipes inside if/while.
* This is used to control execution.
* RES_FOR and RES_IN are NOT sticky (needed to support
* cases where variable or value happens to match a keyword):
*/
#if ENABLE_HUSH_LOOPS
if (ctx->ctx_res_w == RES_FOR
|| ctx->ctx_res_w == RES_IN)
ctx->ctx_res_w = RES_NONE;
#endif
#if ENABLE_HUSH_CASE
if (ctx->ctx_res_w == RES_MATCH)
ctx->ctx_res_w = RES_CASE_BODY;
if (ctx->ctx_res_w == RES_CASE)
ctx->ctx_res_w = RES_CASE_IN;
#endif
ctx->command = NULL; /* trick done_command below */
/* Create the memory for command, roughly:
* ctx->pipe->cmds = new struct command;
* ctx->command = &ctx->pipe->cmds[0];
*/
done_command(ctx);
//debug_print_tree(ctx->list_head, 10);
}
debug_printf_parse("done_pipe return\n");
}
static void initialize_context(struct parse_context *ctx)
{
memset(ctx, 0, sizeof(*ctx));
ctx->pipe = ctx->list_head = new_pipe();
/* Create the memory for command, roughly:
* ctx->pipe->cmds = new struct command;
* ctx->command = &ctx->pipe->cmds[0];
*/
done_command(ctx);
}
/* If a reserved word is found and processed, parse context is modified
* and 1 is returned.
*/
#if HAS_KEYWORDS
struct reserved_combo {
char literal[6];
unsigned char res;
unsigned char assignment_flag;
int flag;
};
enum {
FLAG_END = (1 << RES_NONE ),
# if ENABLE_HUSH_IF
FLAG_IF = (1 << RES_IF ),
FLAG_THEN = (1 << RES_THEN ),
FLAG_ELIF = (1 << RES_ELIF ),
FLAG_ELSE = (1 << RES_ELSE ),
FLAG_FI = (1 << RES_FI ),
# endif
# if ENABLE_HUSH_LOOPS
FLAG_FOR = (1 << RES_FOR ),
FLAG_WHILE = (1 << RES_WHILE),
FLAG_UNTIL = (1 << RES_UNTIL),
FLAG_DO = (1 << RES_DO ),
FLAG_DONE = (1 << RES_DONE ),
FLAG_IN = (1 << RES_IN ),
# endif
# if ENABLE_HUSH_CASE
FLAG_MATCH = (1 << RES_MATCH),
FLAG_ESAC = (1 << RES_ESAC ),
# endif
FLAG_START = (1 << RES_XXXX ),
};
static const struct reserved_combo* match_reserved_word(o_string *word)
{
/* Mostly a list of accepted follow-up reserved words.
* FLAG_END means we are done with the sequence, and are ready
* to turn the compound list into a command.
* FLAG_START means the word must start a new compound list.
*/
static const struct reserved_combo reserved_list[] = {
# if ENABLE_HUSH_IF
{ "!", RES_NONE, NOT_ASSIGNMENT , 0 },
{ "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
{ "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
{ "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
{ "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
{ "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
# endif
# if ENABLE_HUSH_LOOPS
{ "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
{ "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
{ "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
{ "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
{ "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
{ "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
# endif
# if ENABLE_HUSH_CASE
{ "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
{ "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
# endif
};
const struct reserved_combo *r;
for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
if (strcmp(word->data, r->literal) == 0)
return r;
}
return NULL;
}
/* Return 0: not a keyword, 1: keyword
*/
static int reserved_word(o_string *word, struct parse_context *ctx)
{
# if ENABLE_HUSH_CASE
static const struct reserved_combo reserved_match = {
"", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
};
# endif
const struct reserved_combo *r;
if (word->has_quoted_part)
return 0;
r = match_reserved_word(word);
if (!r)
return 0;
debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
# if ENABLE_HUSH_CASE
if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
/* "case word IN ..." - IN part starts first MATCH part */
r = &reserved_match;
} else
# endif
if (r->flag == 0) { /* '!' */
if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
syntax_error("! ! command");
ctx->ctx_res_w = RES_SNTX;
}
ctx->ctx_inverted = 1;
return 1;
}
if (r->flag & FLAG_START) {
struct parse_context *old;
old = xmalloc(sizeof(*old));
debug_printf_parse("push stack %p\n", old);
*old = *ctx; /* physical copy */
initialize_context(ctx);
ctx->stack = old;
} else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
syntax_error_at(word->data);
ctx->ctx_res_w = RES_SNTX;
return 1;
} else {
/* "{...} fi" is ok. "{...} if" is not
* Example:
* if { echo foo; } then { echo bar; } fi */
if (ctx->command->group)
done_pipe(ctx, PIPE_SEQ);
}
ctx->ctx_res_w = r->res;
ctx->old_flag = r->flag;
word->o_assignment = r->assignment_flag;
debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
if (ctx->old_flag & FLAG_END) {
struct parse_context *old;
done_pipe(ctx, PIPE_SEQ);
debug_printf_parse("pop stack %p\n", ctx->stack);
old = ctx->stack;
old->command->group = ctx->list_head;
old->command->cmd_type = CMD_NORMAL;
# if !BB_MMU
o_addstr(&old->as_string, ctx->as_string.data);
o_free_unsafe(&ctx->as_string);
old->command->group_as_string = xstrdup(old->as_string.data);
debug_printf_parse("pop, remembering as:'%s'\n",
old->command->group_as_string);
# endif
*ctx = *old; /* physical copy */
free(old);
}
return 1;
}
#endif /* HAS_KEYWORDS */
/* Word is complete, look at it and update parsing context.
* Normal return is 0. Syntax errors return 1.
* Note: on return, word is reset, but not o_free'd!
*/
static int done_word(o_string *word, struct parse_context *ctx)
{
struct command *command = ctx->command;
debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
if (word->length == 0 && !word->has_quoted_part) {
debug_printf_parse("done_word return 0: true null, ignored\n");
return 0;
}
if (ctx->pending_redirect) {
/* We do not glob in e.g. >*.tmp case. bash seems to glob here
* only if run as "bash", not "sh" */
/* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
* "2.7 Redirection
* ...the word that follows the redirection operator
* shall be subjected to tilde expansion, parameter expansion,
* command substitution, arithmetic expansion, and quote
* removal. Pathname expansion shall not be performed
* on the word by a non-interactive shell; an interactive
* shell may perform it, but shall do so only when
* the expansion would result in one word."
*/
ctx->pending_redirect->rd_filename = xstrdup(word->data);
/* Cater for >\file case:
* >\a creates file a; >\\a, >"\a", >"\\a" create file \a
* Same with heredocs:
* for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
*/
if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
unbackslash(ctx->pending_redirect->rd_filename);
/* Is it <<"HEREDOC"? */
if (word->has_quoted_part) {
ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
}
}
debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
ctx->pending_redirect = NULL;
} else {
#if HAS_KEYWORDS
# if ENABLE_HUSH_CASE
if (ctx->ctx_dsemicolon
&& strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
) {
/* already done when ctx_dsemicolon was set to 1: */
/* ctx->ctx_res_w = RES_MATCH; */
ctx->ctx_dsemicolon = 0;
} else
# endif
if (!command->argv /* if it's the first word... */
# if ENABLE_HUSH_LOOPS
&& ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
&& ctx->ctx_res_w != RES_IN
# endif
# if ENABLE_HUSH_CASE
&& ctx->ctx_res_w != RES_CASE
# endif
) {
int reserved = reserved_word(word, ctx);
debug_printf_parse("checking for reserved-ness: %d\n", reserved);
if (reserved) {
o_reset_to_empty_unquoted(word);
debug_printf_parse("done_word return %d\n",
(ctx->ctx_res_w == RES_SNTX));
return (ctx->ctx_res_w == RES_SNTX);
}
# if ENABLE_HUSH_BASH_COMPAT
if (strcmp(word->data, "[[") == 0) {
command->cmd_type = CMD_SINGLEWORD_NOGLOB;
}
/* fall through */
# endif
}
#endif
if (command->group) {
/* "{ echo foo; } echo bar" - bad */
syntax_error_at(word->data);
debug_printf_parse("done_word return 1: syntax error, "
"groups and arglists don't mix\n");
return 1;
}
/* If this word wasn't an assignment, next ones definitely
* can't be assignments. Even if they look like ones. */
if (word->o_assignment != DEFINITELY_ASSIGNMENT
&& word->o_assignment != WORD_IS_KEYWORD
) {
word->o_assignment = NOT_ASSIGNMENT;
} else {
if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
command->assignment_cnt++;
debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
}
debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
word->o_assignment = MAYBE_ASSIGNMENT;
}
debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
if (word->has_quoted_part
/* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
&& (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
/* (otherwise it's known to be not empty and is already safe) */
) {
/* exclude "$@" - it can expand to no word despite "" */
char *p = word->data;
while (p[0] == SPECIAL_VAR_SYMBOL
&& (p[1] & 0x7f) == '@'
&& p[2] == SPECIAL_VAR_SYMBOL
) {
p += 3;
}
}
command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
debug_print_strings("word appended to argv", command->argv);
}
#if ENABLE_HUSH_LOOPS
if (ctx->ctx_res_w == RES_FOR) {
if (word->has_quoted_part
|| !is_well_formed_var_name(command->argv[0], '\0')
) {
/* bash says just "not a valid identifier" */
syntax_error("not a valid identifier in for");
return 1;
}
/* Force FOR to have just one word (variable name) */
/* NB: basically, this makes hush see "for v in ..."
* syntax as if it is "for v; in ...". FOR and IN become
* two pipe structs in parse tree. */
done_pipe(ctx, PIPE_SEQ);
}
#endif
#if ENABLE_HUSH_CASE
/* Force CASE to have just one word */
if (ctx->ctx_res_w == RES_CASE) {
done_pipe(ctx, PIPE_SEQ);
}
#endif
o_reset_to_empty_unquoted(word);
debug_printf_parse("done_word return 0\n");
return 0;
}
/* Peek ahead in the input to find out if we have a "&n" construct,
* as in "2>&1", that represents duplicating a file descriptor.
* Return:
* REDIRFD_CLOSE if >&- "close fd" construct is seen,
* REDIRFD_SYNTAX_ERR if syntax error,
* REDIRFD_TO_FILE if no & was seen,
* or the number found.
*/
#if BB_MMU
#define parse_redir_right_fd(as_string, input) \
parse_redir_right_fd(input)
#endif
static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
{
int ch, d, ok;
ch = i_peek(input);
if (ch != '&')
return REDIRFD_TO_FILE;
ch = i_getch(input); /* get the & */
nommu_addchr(as_string, ch);
ch = i_peek(input);
if (ch == '-') {
ch = i_getch(input);
nommu_addchr(as_string, ch);
return REDIRFD_CLOSE;
}
d = 0;
ok = 0;
while (ch != EOF && isdigit(ch)) {
d = d*10 + (ch-'0');
ok = 1;
ch = i_getch(input);
nommu_addchr(as_string, ch);
ch = i_peek(input);
}
if (ok) return d;
//TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
bb_error_msg("ambiguous redirect");
return REDIRFD_SYNTAX_ERR;
}
/* Return code is 0 normal, 1 if a syntax error is detected
*/
static int parse_redirect(struct parse_context *ctx,
int fd,
redir_type style,
struct in_str *input)
{
struct command *command = ctx->command;
struct redir_struct *redir;
struct redir_struct **redirp;
int dup_num;
dup_num = REDIRFD_TO_FILE;
if (style != REDIRECT_HEREDOC) {
/* Check for a '>&1' type redirect */
dup_num = parse_redir_right_fd(&ctx->as_string, input);
if (dup_num == REDIRFD_SYNTAX_ERR)
return 1;
} else {
int ch = i_peek(input);
dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
if (dup_num) { /* <<-... */
ch = i_getch(input);
nommu_addchr(&ctx->as_string, ch);
ch = i_peek(input);
}
}
if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
int ch = i_peek(input);
if (ch == '|') {
/* >|FILE redirect ("clobbering" >).
* Since we do not support "set -o noclobber" yet,
* >| and > are the same for now. Just eat |.
*/
ch = i_getch(input);
nommu_addchr(&ctx->as_string, ch);
}
}
/* Create a new redir_struct and append it to the linked list */
redirp = &command->redirects;
while ((redir = *redirp) != NULL) {
redirp = &(redir->next);
}
*redirp = redir = xzalloc(sizeof(*redir));
/* redir->next = NULL; */
/* redir->rd_filename = NULL; */
redir->rd_type = style;
redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
redir_table[style].descrip);
redir->rd_dup = dup_num;
if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
/* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */
debug_printf_parse("duplicating redirect '%d>&%d'\n",
redir->rd_fd, redir->rd_dup);
} else {
/* Set ctx->pending_redirect, so we know what to do at the
* end of the next parsed word. */
ctx->pending_redirect = redir;
}
return 0;
}
/* If a redirect is immediately preceded by a number, that number is
* supposed to tell which file descriptor to redirect. This routine
* looks for such preceding numbers. In an ideal world this routine
* needs to handle all the following classes of redirects...
* echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
* echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
* echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
* echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
*
* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
* "2.7 Redirection
* ... If n is quoted, the number shall not be recognized as part of
* the redirection expression. For example:
* echo \2>a
* writes the character 2 into file a"
* We are getting it right by setting ->has_quoted_part on any \<char>
*
* A -1 return means no valid number was found,
* the caller should use the appropriate default for this redirection.
*/
static int redirect_opt_num(o_string *o)
{
int num;
if (o->data == NULL)
return -1;
num = bb_strtou(o->data, NULL, 10);
if (errno || num < 0)
return -1;
o_reset_to_empty_unquoted(o);
return num;
}
#if BB_MMU
#define fetch_till_str(as_string, input, word, skip_tabs) \
fetch_till_str(input, word, skip_tabs)
#endif
static char *fetch_till_str(o_string *as_string,
struct in_str *input,
const char *word,
int heredoc_flags)
{
o_string heredoc = NULL_O_STRING;
unsigned past_EOL;
int prev = 0; /* not \ */
int ch;
goto jump_in;
while (1) {
ch = i_getch(input);
if (ch != EOF)
nommu_addchr(as_string, ch);
if ((ch == '\n' || ch == EOF)
&& ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
) {
if (strcmp(heredoc.data + past_EOL, word) == 0) {
heredoc.data[past_EOL] = '\0';
debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
return heredoc.data;
}
while (ch == '\n') {
o_addchr(&heredoc, ch);
prev = ch;
jump_in:
past_EOL = heredoc.length;
do {
ch = i_getch(input);
if (ch != EOF)
nommu_addchr(as_string, ch);
} while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
}
}
if (ch == EOF) {
o_free_unsafe(&heredoc);
return NULL;
}
o_addchr(&heredoc, ch);
nommu_addchr(as_string, ch);
if (prev == '\\' && ch == '\\')
/* Correctly handle foo\\<eol> (not a line cont.) */
prev = 0; /* not \ */
else
prev = ch;
}
}
/* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
* and load them all. There should be exactly heredoc_cnt of them.
*/
static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
{
struct pipe *pi = ctx->list_head;
while (pi && heredoc_cnt) {
int i;
struct command *cmd = pi->cmds;
debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
pi->num_cmds,
cmd->argv ? cmd->argv[0] : "NONE");
for (i = 0; i < pi->num_cmds; i++) {
struct redir_struct *redir = cmd->redirects;
debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
i, cmd->argv ? cmd->argv[0] : "NONE");
while (redir) {
if (redir->rd_type == REDIRECT_HEREDOC) {
char *p;
redir->rd_type = REDIRECT_HEREDOC2;
/* redir->rd_dup is (ab)used to indicate <<- */
p = fetch_till_str(&ctx->as_string, input,
redir->rd_filename, redir->rd_dup);
if (!p) {
syntax_error("unexpected EOF in here document");
return 1;
}
free(redir->rd_filename);
redir->rd_filename = p;
heredoc_cnt--;
}
redir = redir->next;
}
cmd++;
}
pi = pi->next;
}
#if 0
/* Should be 0. If it isn't, it's a parse error */
if (heredoc_cnt)
bb_error_msg_and_die("heredoc BUG 2");
#endif
return 0;
}
static int run_list(struct pipe *pi);
#if BB_MMU
#define parse_stream(pstring, input, end_trigger) \
parse_stream(input, end_trigger)
#endif
static struct pipe *parse_stream(char **pstring,
struct in_str *input,
int end_trigger);
#if !ENABLE_HUSH_FUNCTIONS
#define parse_group(dest, ctx, input, ch) \
parse_group(ctx, input, ch)
#endif
static int parse_group(o_string *dest, struct parse_context *ctx,
struct in_str *input, int ch)
{
/* dest contains characters seen prior to ( or {.
* Typically it's empty, but for function defs,
* it contains function name (without '()'). */
struct pipe *pipe_list;
int endch;
struct command *command = ctx->command;
debug_printf_parse("parse_group entered\n");
#if ENABLE_HUSH_FUNCTIONS
if (ch == '(' && !dest->has_quoted_part) {
if (dest->length)
if (done_word(dest, ctx))
return 1;
if (!command->argv)
goto skip; /* (... */
if (command->argv[1]) { /* word word ... (... */
syntax_error_unexpected_ch('(');
return 1;
}
/* it is "word(..." or "word (..." */
do
ch = i_getch(input);
while (ch == ' ' || ch == '\t');
if (ch != ')') {
syntax_error_unexpected_ch(ch);
return 1;
}
nommu_addchr(&ctx->as_string, ch);
do
ch = i_getch(input);
while (ch == ' ' || ch == '\t' || ch == '\n');
if (ch != '{') {
syntax_error_unexpected_ch(ch);
return 1;
}
nommu_addchr(&ctx->as_string, ch);
command->cmd_type = CMD_FUNCDEF;
goto skip;
}
#endif
#if 0 /* Prevented by caller */
if (command->argv /* word [word]{... */
|| dest->length /* word{... */
|| dest->has_quoted_part /* ""{... */
) {
syntax_error(NULL);
debug_printf_parse("parse_group return 1: "
"syntax error, groups and arglists don't mix\n");
return 1;
}
#endif
#if ENABLE_HUSH_FUNCTIONS
skip:
#endif
endch = '}';
if (ch == '(') {
endch = ')';
command->cmd_type = CMD_SUBSHELL;
} else {
/* bash does not allow "{echo...", requires whitespace */
ch = i_getch(input);
if (ch != ' ' && ch != '\t' && ch != '\n') {
syntax_error_unexpected_ch(ch);
return 1;
}
nommu_addchr(&ctx->as_string, ch);
}
{
#if BB_MMU
# define as_string NULL
#else
char *as_string = NULL;
#endif
pipe_list = parse_stream(&as_string, input, endch);
#if !BB_MMU
if (as_string)
o_addstr(&ctx->as_string, as_string);
#endif
/* empty ()/{} or parse error? */
if (!pipe_list || pipe_list == ERR_PTR) {
/* parse_stream already emitted error msg */
if (!BB_MMU)
free(as_string);
debug_printf_parse("parse_group return 1: "
"parse_stream returned %p\n", pipe_list);
return 1;
}
command->group = pipe_list;
#if !BB_MMU
as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
command->group_as_string = as_string;
debug_printf_parse("end of group, remembering as:'%s'\n",
command->group_as_string);
#endif
#undef as_string
}
debug_printf_parse("parse_group return 0\n");
return 0;
/* command remains "open", available for possible redirects */
}
#if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
/* Subroutines for copying $(...) and `...` things */
static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
/* '...' */
static int add_till_single_quote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = i_getch(input);
if (ch == EOF) {
syntax_error_unterm_ch('\'');
return 0;
}
if (ch == '\'')
return 1;
o_addchr(dest, ch);
}
}
/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
static int add_till_double_quote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = i_getch(input);
if (ch == EOF) {
syntax_error_unterm_ch('"');
return 0;
}
if (ch == '"')
return 1;
if (ch == '\\') { /* \x. Copy both chars. */
o_addchr(dest, ch);
ch = i_getch(input);
}
o_addchr(dest, ch);
if (ch == '`') {
if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
return 0;
o_addchr(dest, ch);
continue;
}
//if (ch == '$') ...
}
}
/* Process `cmd` - copy contents until "`" is seen. Complicated by
* \` quoting.
* "Within the backquoted style of command substitution, backslash
* shall retain its literal meaning, except when followed by: '$', '`', or '\'.
* The search for the matching backquote shall be satisfied by the first
* backquote found without a preceding backslash; during this search,
* if a non-escaped backquote is encountered within a shell comment,
* a here-document, an embedded command substitution of the $(command)
* form, or a quoted string, undefined results occur. A single-quoted
* or double-quoted string that begins, but does not end, within the
* "`...`" sequence produces undefined results."
* Example Output
* echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
*/
static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
{
while (1) {
int ch = i_getch(input);
if (ch == '`')
return 1;
if (ch == '\\') {
/* \x. Copy both unless it is \`, \$, \\ and maybe \" */
ch = i_getch(input);
if (ch != '`'
&& ch != '$'
&& ch != '\\'
&& (!in_dquote || ch != '"')
) {
o_addchr(dest, '\\');
}
}
if (ch == EOF) {
syntax_error_unterm_ch('`');
return 0;
}
o_addchr(dest, ch);
}
}
/* Process $(cmd) - copy contents until ")" is seen. Complicated by
* quoting and nested ()s.
* "With the $(command) style of command substitution, all characters
* following the open parenthesis to the matching closing parenthesis
* constitute the command. Any valid shell script can be used for command,
* except a script consisting solely of redirections which produces
* unspecified results."
* Example Output
* echo $(echo '(TEST)' BEST) (TEST) BEST
* echo $(echo 'TEST)' BEST) TEST) BEST
* echo $(echo \(\(TEST\) BEST) ((TEST) BEST
*
* Also adapted to eat ${var%...} and $((...)) constructs, since ... part
* can contain arbitrary constructs, just like $(cmd).
* In bash compat mode, it needs to also be able to stop on ':' or '/'
* for ${var:N[:M]} and ${var/P[/R]} parsing.
*/
#define DOUBLE_CLOSE_CHAR_FLAG 0x80
static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
{
int ch;
char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
# if ENABLE_HUSH_BASH_COMPAT
char end_char2 = end_ch >> 8;
# endif
end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
while (1) {
ch = i_getch(input);
if (ch == EOF) {
syntax_error_unterm_ch(end_ch);
return 0;
}
if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
if (!dbl)
break;
/* we look for closing )) of $((EXPR)) */
if (i_peek(input) == end_ch) {
i_getch(input); /* eat second ')' */
break;
}
}
o_addchr(dest, ch);
if (ch == '(' || ch == '{') {
ch = (ch == '(' ? ')' : '}');
if (!add_till_closing_bracket(dest, input, ch))
return 0;
o_addchr(dest, ch);
continue;
}
if (ch == '\'') {
if (!add_till_single_quote(dest, input))
return 0;
o_addchr(dest, ch);
continue;
}
if (ch == '"') {
if (!add_till_double_quote(dest, input))
return 0;
o_addchr(dest, ch);
continue;
}
if (ch == '`') {
if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
return 0;
o_addchr(dest, ch);
continue;
}
if (ch == '\\') {
/* \x. Copy verbatim. Important for \(, \) */
ch = i_getch(input);
if (ch == EOF) {
syntax_error_unterm_ch(')');
return 0;
}
o_addchr(dest, ch);
continue;
}
}
return ch;
}
#endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
/* Return code: 0 for OK, 1 for syntax error */
#if BB_MMU
#define parse_dollar(as_string, dest, input, quote_mask) \
parse_dollar(dest, input, quote_mask)
#define as_string NULL
#endif
static int parse_dollar(o_string *as_string,
o_string *dest,
struct in_str *input, unsigned char quote_mask)
{
int ch = i_peek(input); /* first character after the $ */
debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
if (isalpha(ch)) {
ch = i_getch(input);
nommu_addchr(as_string, ch);
make_var:
o_addchr(dest, SPECIAL_VAR_SYMBOL);
while (1) {
debug_printf_parse(": '%c'\n", ch);
o_addchr(dest, ch | quote_mask);
quote_mask = 0;
ch = i_peek(input);
if (!isalnum(ch) && ch != '_')
break;
ch = i_getch(input);
nommu_addchr(as_string, ch);
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
} else if (isdigit(ch)) {
make_one_char_var:
ch = i_getch(input);
nommu_addchr(as_string, ch);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
debug_printf_parse(": '%c'\n", ch);
o_addchr(dest, ch | quote_mask);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
} else switch (ch) {
case '$': /* pid */
case '!': /* last bg pid */
case '?': /* last exit code */
case '#': /* number of args */
case '*': /* args */
case '@': /* args */
goto make_one_char_var;
case '{': {
o_addchr(dest, SPECIAL_VAR_SYMBOL);
ch = i_getch(input); /* eat '{' */
nommu_addchr(as_string, ch);
ch = i_getch(input); /* first char after '{' */
/* It should be ${?}, or ${#var},
* or even ${?+subst} - operator acting on a special variable,
* or the beginning of variable name.
*/
if (ch == EOF
|| (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
) {
bad_dollar_syntax:
syntax_error_unterm_str("${name}");
debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
return 0;
}
nommu_addchr(as_string, ch);
ch |= quote_mask;
/* It's possible to just call add_till_closing_bracket() at this point.
* However, this regresses some of our testsuite cases
* which check invalid constructs like ${%}.
* Oh well... let's check that the var name part is fine... */
while (1) {
unsigned pos;
o_addchr(dest, ch);
debug_printf_parse(": '%c'\n", ch);
ch = i_getch(input);
nommu_addchr(as_string, ch);
if (ch == '}')
break;
if (!isalnum(ch) && ch != '_') {
unsigned end_ch;
unsigned char last_ch;
/* handle parameter expansions
* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
*/
if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
goto bad_dollar_syntax;
/* Eat everything until closing '}' (or ':') */
end_ch = '}';
if (ENABLE_HUSH_BASH_COMPAT
&& ch == ':'
&& !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
) {
/* It's ${var:N[:M]} thing */
end_ch = '}' * 0x100 + ':';
}
if (ENABLE_HUSH_BASH_COMPAT
&& ch == '/'
) {
/* It's ${var/[/]pattern[/repl]} thing */
if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
i_getch(input);
nommu_addchr(as_string, '/');
ch = '\\';
}
end_ch = '}' * 0x100 + '/';
}
o_addchr(dest, ch);
again:
if (!BB_MMU)
pos = dest->length;
#if ENABLE_HUSH_DOLLAR_OPS
last_ch = add_till_closing_bracket(dest, input, end_ch);
if (last_ch == 0) /* error? */
return 0;
#else
#error Simple code to only allow ${var} is not implemented
#endif
if (as_string) {
o_addstr(as_string, dest->data + pos);
o_addchr(as_string, last_ch);
}
if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
/* close the first block: */
o_addchr(dest, SPECIAL_VAR_SYMBOL);
/* while parsing N from ${var:N[:M]}
* or pattern from ${var/[/]pattern[/repl]} */
if ((end_ch & 0xff) == last_ch) {
/* got ':' or '/'- parse the rest */
end_ch = '}';
goto again;
}
/* got '}' */
if (end_ch == '}' * 0x100 + ':') {
/* it's ${var:N} - emulate :999999999 */
o_addstr(dest, "999999999");
} /* else: it's ${var/[/]pattern} */
}
break;
}
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
}
#if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
case '(': {
unsigned pos;
ch = i_getch(input);
nommu_addchr(as_string, ch);
# if ENABLE_SH_MATH_SUPPORT
if (i_peek(input) == '(') {
ch = i_getch(input);
nommu_addchr(as_string, ch);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
o_addchr(dest, /*quote_mask |*/ '+');
if (!BB_MMU)
pos = dest->length;
if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
return 0; /* error */
if (as_string) {
o_addstr(as_string, dest->data + pos);
o_addchr(as_string, ')');
o_addchr(as_string, ')');
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
}
# endif
# if ENABLE_HUSH_TICK
o_addchr(dest, SPECIAL_VAR_SYMBOL);
o_addchr(dest, quote_mask | '`');
if (!BB_MMU)
pos = dest->length;
if (!add_till_closing_bracket(dest, input, ')'))
return 0; /* error */
if (as_string) {
o_addstr(as_string, dest->data + pos);
o_addchr(as_string, ')');
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
# endif
break;
}
#endif
case '_':
ch = i_getch(input);
nommu_addchr(as_string, ch);
ch = i_peek(input);
if (isalnum(ch)) { /* it's $_name or $_123 */
ch = '_';
goto make_var;
}
/* else: it's $_ */
/* TODO: $_ and $-: */
/* $_ Shell or shell script name; or last argument of last command
* (if last command wasn't a pipe; if it was, bash sets $_ to "");
* but in command's env, set to full pathname used to invoke it */
/* $- Option flags set by set builtin or shell options (-i etc) */