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/* $Id: cmd-string.c,v 1.31 2010/02/26 13:27:38 tcunha Exp $ */
/*
* Copyright (c) 2008 Nicholas Marriott <nicm@users.sourceforge.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <errno.h>
#include <pwd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "tmux.h"
/*
* Parse a command from a string.
*/
int cmd_string_getc(const char *, size_t *);
void cmd_string_ungetc(size_t *);
char *cmd_string_string(const char *, size_t *, char, int);
char *cmd_string_variable(const char *, size_t *);
char *cmd_string_expand_tilde(const char *, size_t *);
int
cmd_string_getc(const char *s, size_t *p)
{
const u_char *ucs = s;
if (ucs[*p] == '\0')
return (EOF);
return (ucs[(*p)++]);
}
void
cmd_string_ungetc(size_t *p)
{
(*p)--;
}
/*
* Parse command string. Returns -1 on error. If returning -1, cause is error
* string, or NULL for empty command.
*/
int
cmd_string_parse(const char *s, struct cmd_list **cmdlist, char **cause)
{
size_t p;
int ch, i, argc, rval;
char **argv, *buf, *t;
const char *whitespace, *equals;
size_t len;
argv = NULL;
argc = 0;
buf = NULL;
len = 0;
*cause = NULL;
*cmdlist = NULL;
rval = -1;
p = 0;
for (;;) {
ch = cmd_string_getc(s, &p);
switch (ch) {
case '\'':
if ((t = cmd_string_string(s, &p, '\'', 0)) == NULL)
goto error;
buf = xrealloc(buf, 1, len + strlen(t) + 1);
strlcpy(buf + len, t, strlen(t) + 1);
len += strlen(t);
xfree(t);
break;
case '"':
if ((t = cmd_string_string(s, &p, '"', 1)) == NULL)
goto error;
buf = xrealloc(buf, 1, len + strlen(t) + 1);
strlcpy(buf + len, t, strlen(t) + 1);
len += strlen(t);
xfree(t);
break;
case '$':
if ((t = cmd_string_variable(s, &p)) == NULL)
goto error;
buf = xrealloc(buf, 1, len + strlen(t) + 1);
strlcpy(buf + len, t, strlen(t) + 1);
len += strlen(t);
xfree(t);
break;
case '#':
/* Comment: discard rest of line. */
while ((ch = cmd_string_getc(s, &p)) != EOF)
;
/* FALLTHROUGH */
case EOF:
case ' ':
case '\t':
if (buf != NULL) {
buf = xrealloc(buf, 1, len + 1);
buf[len] = '\0';
argv = xrealloc(argv, argc + 1, sizeof *argv);
argv[argc++] = buf;
buf = NULL;
len = 0;
}
if (ch != EOF)
break;
while (argc != 0) {
equals = strchr(argv[0], '=');
whitespace = argv[0] + strcspn(argv[0], " \t");
if (equals == NULL || equals > whitespace)
break;
environ_put(&global_environ, argv[0]);
argc--;
memmove(argv, argv + 1, argc * (sizeof *argv));
}
if (argc == 0)
goto out;
*cmdlist = cmd_list_parse(argc, argv, cause);
if (*cmdlist == NULL)
goto out;
rval = 0;
goto out;
case '~':
if (buf == NULL) {
if ((t = cmd_string_expand_tilde(s, &p)) == NULL)
goto error;
buf = xrealloc(buf, 1, len + strlen(t) + 1);
strlcpy(buf + len, t, strlen(t) + 1);
len += strlen(t);
xfree(t);
break;
}
/* FALLTHROUGH */
default:
if (len >= SIZE_MAX - 2)
goto error;
buf = xrealloc(buf, 1, len + 1);
buf[len++] = ch;
break;
}
}
error:
xasprintf(cause, "invalid or unknown command: %s", s);
out:
if (buf != NULL)
xfree(buf);
if (argv != NULL) {
for (i = 0; i < argc; i++)
xfree(argv[i]);
xfree(argv);
}
return (rval);
}
char *
cmd_string_string(const char *s, size_t *p, char endch, int esc)
{
int ch;
char *buf, *t;
size_t len;
buf = NULL;
len = 0;
while ((ch = cmd_string_getc(s, p)) != endch) {
switch (ch) {
case EOF:
goto error;
case '\\':
if (!esc)
break;
switch (ch = cmd_string_getc(s, p)) {
case EOF:
goto error;
case 'e':
ch = '\033';
break;
case 'r':
ch = '\r';
break;
case 'n':
ch = '\n';
break;
case 't':
ch = '\t';
break;
}
break;
case '$':
if (!esc)
break;
if ((t = cmd_string_variable(s, p)) == NULL)
goto error;
buf = xrealloc(buf, 1, len + strlen(t) + 1);
strlcpy(buf + len, t, strlen(t) + 1);
len += strlen(t);
xfree(t);
continue;
}
if (len >= SIZE_MAX - 2)
goto error;
buf = xrealloc(buf, 1, len + 1);
buf[len++] = ch;
}
buf = xrealloc(buf, 1, len + 1);
buf[len] = '\0';
return (buf);
error:
if (buf != NULL)
xfree(buf);
return (NULL);
}
char *
cmd_string_variable(const char *s, size_t *p)
{
int ch, fch;
char *buf, *t;
size_t len;
#define cmd_string_first(ch) ((ch) == '_' || \
((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z'))
#define cmd_string_other(ch) ((ch) == '_' || \
((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z') || \
((ch) >= '0' && (ch) <= '9'))
buf = NULL;
len = 0;
fch = EOF;
switch (ch = cmd_string_getc(s, p)) {
case EOF:
goto error;
case '{':
fch = '{';
ch = cmd_string_getc(s, p);
if (!cmd_string_first(ch))
goto error;
/* FALLTHROUGH */
default:
if (!cmd_string_first(ch)) {
xasprintf(&t, "$%c", ch);
return (t);
}
buf = xrealloc(buf, 1, len + 1);
buf[len++] = ch;
for (;;) {
ch = cmd_string_getc(s, p);
if (ch == EOF || !cmd_string_other(ch))
break;
else {
if (len >= SIZE_MAX - 3)
goto error;
buf = xrealloc(buf, 1, len + 1);
buf[len++] = ch;
}
}
}
if (fch == '{' && ch != '}')
goto error;
if (ch != EOF && fch != '{')
cmd_string_ungetc(p); /* ch */
buf = xrealloc(buf, 1, len + 1);
buf[len] = '\0';
if ((t = getenv(buf)) == NULL) {
xfree(buf);
return (xstrdup(""));
}
xfree(buf);
return (xstrdup(t));
error:
if (buf != NULL)
xfree(buf);
return (NULL);
}
char *
cmd_string_expand_tilde(const char *s, size_t *p)
{
struct passwd *pw;
char *home, *path, *username;
home = NULL;
if (cmd_string_getc(s, p) == '/') {
if ((home = getenv("HOME")) == NULL || *home == '\0') {
if ((pw = getpwuid(getuid())) != NULL)
home = pw->pw_dir;
}
} else {
cmd_string_ungetc(p);
if ((username = cmd_string_string(s, p, '/', 0)) == NULL)
return (NULL);
if ((pw = getpwnam(username)) != NULL)
home = pw->pw_dir;
xfree(username);
}
if (home == NULL)
return (NULL);
xasprintf(&path, "%s/", home);
return (path);
}