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
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
|
/* command.h -- The structures used internally to represent commands, and
the extern declarations of the functions used to create them. */
/* Copyright (C) 1993 Free Software Foundation, Inc.
This file is part of GNU Bash, the Bourne Again SHell.
Bash 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 2, or (at your option) any later
version.
Bash 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 Bash; see the file COPYING. If not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#if !defined (_COMMAND_H_)
#define _COMMAND_H_
#include "stdc.h"
/* Instructions describing what kind of thing to do for a redirection. */
enum r_instruction {
r_output_direction, r_input_direction, r_inputa_direction,
r_appending_to, r_reading_until, r_duplicating_input,
r_duplicating_output, r_deblank_reading_until, r_close_this,
r_err_and_out, r_input_output, r_output_force,
r_duplicating_input_word, r_duplicating_output_word
};
/* Redirection errors. */
#define AMBIGUOUS_REDIRECT -1
#define NOCLOBBER_REDIRECT -2
#define RESTRICTED_REDIRECT -3 /* can only happen in restricted shells. */
#define HEREDOC_REDIRECT -4 /* here-doc temp file can't be created */
#define OUTPUT_REDIRECT(ri) \
(ri == r_output_direction || ri == r_input_output || ri == r_err_and_out)
#define INPUT_REDIRECT(ri) \
(ri == r_input_direction || ri == r_inputa_direction || ri == r_input_output)
#define WRITE_REDIRECT(ri) \
(ri == r_output_direction || \
ri == r_input_output || \
ri == r_err_and_out || \
ri == r_appending_to || \
ri == r_output_force)
/* Command Types: */
enum command_type { cm_for, cm_case, cm_while, cm_if, cm_simple, cm_select,
cm_connection, cm_function_def, cm_until, cm_group };
/* Possible values for the `flags' field of a WORD_DESC. */
#define W_HASDOLLAR 0x01 /* Dollar sign present. */
#define W_QUOTED 0x02 /* Some form of quote character is present. */
#define W_ASSIGNMENT 0x04 /* This word is a variable assignment. */
#define W_GLOBEXP 0x08 /* This word is the result of a glob expansion. */
#define W_NOSPLIT 0x10 /* Do not perform word splitting on this word. */
/* Possible values for subshell_environment */
#define SUBSHELL_ASYNC 0x01 /* subshell caused by `command &' */
#define SUBSHELL_PAREN 0x02 /* subshell caused by ( ... ) */
#define SUBSHELL_COMSUB 0x04 /* subshell caused by `command` or $(command) */
#define SUBSHELL_FORK 0x08 /* subshell caused by executing a disk command */
/* A structure which represents a word. */
typedef struct word_desc {
char *word; /* Zero terminated string. */
int flags; /* Flags associated with this word. */
} WORD_DESC;
/* A linked list of words. */
typedef struct word_list {
struct word_list *next;
WORD_DESC *word;
} WORD_LIST;
/* **************************************************************** */
/* */
/* Shell Command Structs */
/* */
/* **************************************************************** */
/* What a redirection descriptor looks like. If FLAGS is IS_DESCRIPTOR,
then we use REDIRECTEE.DEST, else we use the file specified. */
typedef union {
long dest; /* Place to redirect REDIRECTOR to, or ... */
WORD_DESC *filename; /* filename to redirect to. */
} REDIRECTEE;
typedef struct redirect {
struct redirect *next; /* Next element, or NULL. */
int redirector; /* Descriptor to be redirected. */
int flags; /* Flag value for `open'. */
enum r_instruction instruction; /* What to do with the information. */
REDIRECTEE redirectee; /* File descriptor or filename */
char *here_doc_eof; /* The word that appeared in <<foo. */
} REDIRECT;
/* An element used in parsing. A single word or a single redirection.
This is an ephemeral construct. */
typedef struct element {
WORD_DESC *word;
REDIRECT *redirect;
} ELEMENT;
/* Possible values for command->flags. */
#define CMD_WANT_SUBSHELL 0x01 /* User wants a subshell: ( command ) */
#define CMD_FORCE_SUBSHELL 0x02 /* Shell needs to force a subshell. */
#define CMD_INVERT_RETURN 0x04 /* Invert the exit value. */
#define CMD_IGNORE_RETURN 0x08 /* Ignore the exit value. For set -e. */
#define CMD_NO_FUNCTIONS 0x10 /* Ignore functions during command lookup. */
#define CMD_INHIBIT_EXPANSION 0x20 /* Do not expand the command words. */
#define CMD_NO_FORK 0x40 /* Don't fork; just call execve */
#define CMD_TIME_PIPELINE 0x80 /* Time a pipeline */
#define CMD_TIME_POSIX 0x100 /* time -p; use POSIX.2 time output spec. */
#define CMD_AMPERSAND 0x200 /* command & */
#define CMD_STDIN_REDIR 0x400 /* async command needs implicit </dev/null */
/* What a command looks like. */
typedef struct command {
enum command_type type; /* FOR CASE WHILE IF CONNECTION or SIMPLE. */
int flags; /* Flags controlling execution environment. */
int line; /* line number the command starts on */
REDIRECT *redirects; /* Special redirects for FOR CASE, etc. */
union {
struct for_com *For;
struct case_com *Case;
struct while_com *While;
struct if_com *If;
struct connection *Connection;
struct simple_com *Simple;
struct function_def *Function_def;
struct group_com *Group;
#if defined (SELECT_COMMAND)
struct select_com *Select;
#endif
} value;
} COMMAND;
/* Structure used to represent the CONNECTION type. */
typedef struct connection {
int ignore; /* Unused; simplifies make_command (). */
COMMAND *first; /* Pointer to the first command. */
COMMAND *second; /* Pointer to the second command. */
int connector; /* What separates this command from others. */
} CONNECTION;
/* Structures used to represent the CASE command. */
/* Pattern/action structure for CASE_COM. */
typedef struct pattern_list {
struct pattern_list *next; /* Clause to try in case this one failed. */
WORD_LIST *patterns; /* Linked list of patterns to test. */
COMMAND *action; /* Thing to execute if a pattern matches. */
} PATTERN_LIST;
/* The CASE command. */
typedef struct case_com {
int flags; /* See description of CMD flags. */
WORD_DESC *word; /* The thing to test. */
PATTERN_LIST *clauses; /* The clauses to test against, or NULL. */
} CASE_COM;
/* FOR command. */
typedef struct for_com {
int flags; /* See description of CMD flags. */
WORD_DESC *name; /* The variable name to get mapped over. */
WORD_LIST *map_list; /* The things to map over. This is never NULL. */
COMMAND *action; /* The action to execute.
During execution, NAME is bound to successive
members of MAP_LIST. */
} FOR_COM;
#if defined (SELECT_COMMAND)
/* KSH SELECT command. */
typedef struct select_com {
int flags; /* See description of CMD flags. */
WORD_DESC *name; /* The variable name to get mapped over. */
WORD_LIST *map_list; /* The things to map over. This is never NULL. */
COMMAND *action; /* The action to execute.
During execution, NAME is bound to the member of
MAP_LIST chosen by the user. */
} SELECT_COM;
#endif /* SELECT_COMMAND */
/* IF command. */
typedef struct if_com {
int flags; /* See description of CMD flags. */
COMMAND *test; /* Thing to test. */
COMMAND *true_case; /* What to do if the test returned non-zero. */
COMMAND *false_case; /* What to do if the test returned zero. */
} IF_COM;
/* WHILE command. */
typedef struct while_com {
int flags; /* See description of CMD flags. */
COMMAND *test; /* Thing to test. */
COMMAND *action; /* Thing to do while test is non-zero. */
} WHILE_COM;
/* The "simple" command. Just a collection of words and redirects. */
typedef struct simple_com {
int flags; /* See description of CMD flags. */
WORD_LIST *words; /* The program name, the arguments,
variable assignments, etc. */
REDIRECT *redirects; /* Redirections to perform. */
int line; /* line number the command starts on */
} SIMPLE_COM;
/* The "function definition" command. */
typedef struct function_def {
int ignore; /* See description of CMD flags. */
WORD_DESC *name; /* The name of the function. */
COMMAND *command; /* The parsed execution tree. */
int line; /* Line number the function def starts on. */
} FUNCTION_DEF;
/* A command that is `grouped' allows pipes and redirections to affect all
commands in the group. */
typedef struct group_com {
int ignore; /* See description of CMD flags. */
COMMAND *command;
} GROUP_COM;
extern COMMAND *global_command;
/* Forward declarations of functions declared in copy_cmd.c. */
extern WORD_DESC *copy_word __P((WORD_DESC *));
extern WORD_LIST *copy_word_list __P((WORD_LIST *));
extern REDIRECT *copy_redirect __P((REDIRECT *));
extern REDIRECT *copy_redirects __P((REDIRECT *));
extern COMMAND *copy_command __P((COMMAND *));
#endif /* _COMMAND_H_ */
|