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SGI Freeware 1998 November
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Freeware November 1998.img
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fw_GNUbash.idb
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usr
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src
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bash-1.14.6
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command.h.z
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command.h
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1998-01-21
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/* 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
};
/* 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 };
/* A structure which represents a word. */
typedef struct word_desc {
char *word; /* Zero terminated string. */
int dollar_present; /* Non-zero means dollar sign present. */
int quoted; /* Non-zero means single, double, or back quote
or backslash is present. */
int assignment; /* Non-zero means that this word contains an
assignment. */
} 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 */
/* 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_def" command. This isn't really a command, but it is
represented as such for now. If the function def appears within
`(' `)' the parser tries to set the SUBSHELL bit of the command. That
means that FUNCTION_DEF has to be run through the executor. Maybe this
command should be defined in a subshell. Who knows or cares. */
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. */
} FUNCTION_DEF;
/* A command that is `grouped' allows pipes to take effect over
the entire command structure. */
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 */