-
Notifications
You must be signed in to change notification settings - Fork 0
/
command-internals.h
72 lines (60 loc) · 1.73 KB
/
command-internals.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
// UCLA CS 111 Lab 1 command internals
// Copyright 2012-2014 Paul Eggert.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
enum token_type
{
IF,
FI,
ELSE,
THEN,
WHILE,
DO,
DONE,
UNTIL,
SEMICOLON,
PIPE,
OPEN_PAREN,
CLOSE_PAREN,
LESS_THAN,
GREATER_THAN,
WORD,
NEW_LINE,
OTHER
};
enum command_type
{
IF_COMMAND, // if A then B else C fi
PIPE_COMMAND, // A | B
SEQUENCE_COMMAND, // A ; B
SIMPLE_COMMAND, // a simple command
SUBSHELL_COMMAND, // ( A )
UNTIL_COMMAND, // until A do B done
WHILE_COMMAND, // while A do B done
};
// Data associated with a command.
struct command
{
enum command_type type;
// Exit status, or -1 if not known (e.g., because it has not exited yet).
int status;
// I/O redirections, or null if none.
char *input;
char *output;
union
{
// For SIMPLE_COMMAND.
char **word;
// For all other kinds of commands. Trailing entries are unused.
// Only IF_COMMAND uses all three entries.
struct command *command[3];
} u;
};