243 lines
8.5 KiB
C
243 lines
8.5 KiB
C
/* shell.h -- The data structures used by the shell */
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#include "config.h"
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#include "general.h"
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#include "variables.h"
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#include "quit.h"
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#include "maxpath.h"
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#include "unwind_prot.h"
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extern int EOF_Reached;
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#define NO_PIPE -1
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#define REDIRECT_BOTH -2
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#define IS_DESCRIPTOR -1
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#define NO_VARIABLE -1
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/* A bunch of stuff for flow of control using setjmp () and longjmp (). */
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#include <setjmp.h>
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extern jmp_buf top_level, catch;
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#define NOT_JUMPED 0 /* Not returning from a longjmp. */
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#define FORCE_EOF 1 /* We want to stop parsing. */
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#define DISCARD 2 /* Discard current command. */
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#define EXITPROG 3 /* Unconditionally exit the program now. */
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/* Values that can be returned by execute_command (). */
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#define EXECUTION_FAILURE 1
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#define EXECUTION_SUCCESS 0
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/* Special exit status used when the shell is asked to execute a
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binary file as a shell script. */
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#define EX_BINARY_FILE 126
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/* The list of characters that are quoted in double-quotes with a
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backslash. Other characters following a backslash cause nothing
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special to happen. */
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#define slashify_in_quotes "\\`$\""
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#define slashify_in_here_document "\\`$"
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/* Constants which specify how to handle backslashes and quoting in
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expand_word_internal (). Q_DOUBLE_QUOTES means to use the function
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slashify_in_quotes () to decide whether the backslash should be
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retained. Q_HERE_DOCUMENT means slashify_in_here_document () to
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decide whether to retain the backslash. Q_KEEP_BACKSLASH means
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to unconditionally retain the backslash. */
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#define Q_DOUBLE_QUOTES 0x1
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#define Q_HERE_DOCUMENT 0x2
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#define Q_KEEP_BACKSLASH 0x4
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/* All structs which contain a `next' field should have that field
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as the first field in the struct. This means that functions
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can be written to handle the general case for linked lists. */
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typedef struct g_list {
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struct g_list *next;
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} GENERIC_LIST;
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/* Instructions describing what kind of thing to do for a redirection. */
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enum r_instruction {
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r_output_direction, r_input_direction, r_inputa_direction,
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r_appending_to, r_reading_until, r_duplicating_input,
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r_duplicating_output, r_deblank_reading_until, r_close_this,
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r_err_and_out, r_input_output, r_output_force,
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r_duplicating_input_word, r_duplicating_output_word
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};
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/* Command Types: */
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enum command_type { cm_for, cm_case, cm_while, cm_if, cm_simple,
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cm_connection, cm_function_def, cm_until, cm_group };
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/* A structure which represents a word. */
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typedef struct word_desc {
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char *word; /* Zero terminated string. */
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int dollar_present; /* Non-zero means dollar sign present. */
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int quoted; /* Non-zero means single, double, or back quote
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or backslash is present. */
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int assignment; /* Non-zero means that this word contains an assignment. */
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} WORD_DESC;
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/* A linked list of words. */
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typedef struct word_list {
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struct word_list *next;
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WORD_DESC *word;
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} WORD_LIST;
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/* **************************************************************** */
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/* */
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/* Shell Command Structs */
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/* */
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/* **************************************************************** */
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/* What a redirection descriptor looks like. If FLAGS is IS_DESCRIPTOR,
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then we use REDIRECTEE.DEST, else we use the file specified. */
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typedef struct redirect {
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struct redirect *next; /* Next element, or NULL. */
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int redirector; /* Descriptor to be redirected. */
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int flags; /* Flag value for `open'. */
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enum r_instruction instruction; /* What to do with the information. */
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union {
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int dest; /* Place to redirect REDIRECTOR to, or ... */
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WORD_DESC *filename; /* filename to redirect to. */
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} redirectee;
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char *here_doc_eof; /* The word that appeared in <<foo. */
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} REDIRECT;
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/* An element used in parsing. A single word or a single redirection.
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This is an ephemeral construct. */
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typedef struct element {
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WORD_DESC *word;
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REDIRECT *redirect;
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} ELEMENT;
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/* Possible values for command->flags. */
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#define CMD_WANT_SUBSHELL 0x01 /* User wants a subshell: ( command ) */
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#define CMD_FORCE_SUBSHELL 0x02 /* Shell needs to force a subshell. */
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#define CMD_INVERT_RETURN 0x04 /* Invert the exit value. */
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#define CMD_IGNORE_RETURN 0x08 /* Ignore the exit value. For set -e. */
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#define CMD_NO_FUNCTIONS 0x10 /* Ignore functions during command lookup. */
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#define CMD_INHIBIT_EXPANSION 0x20 /* Do not expand the command words. */
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/* What a command looks like. */
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typedef struct command {
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enum command_type type; /* FOR CASE WHILE IF CONNECTION or SIMPLE. */
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int flags; /* Flags controlling execution environment. */
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REDIRECT *redirects; /* Special redirects for FOR CASE, etc. */
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union {
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struct for_com *For;
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struct case_com *Case;
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struct while_com *While;
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struct if_com *If;
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struct connection *Connection;
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struct simple_com *Simple;
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struct function_def *Function_def;
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struct group_com *Group;
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} value;
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} COMMAND;
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/* Structure used to represent the CONNECTION type. */
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typedef struct connection {
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int ignore; /* Unused; simplifies make_command (). */
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COMMAND *first; /* Pointer to the first command. */
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COMMAND *second; /* Pointer to the second command. */
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int connector; /* What separates this command from others. */
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} CONNECTION;
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/* Structures used to represent the CASE command. */
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/* Pattern/action structure for CASE_COM. */
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typedef struct pattern_list {
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struct pattern_list *next; /* Clause to try in case this one failed. */
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WORD_LIST *patterns; /* Linked list of patterns to test. */
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COMMAND *action; /* Thing to execute if a pattern matches. */
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} PATTERN_LIST;
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/* The CASE command. */
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typedef struct case_com {
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int flags; /* See description of CMD flags. */
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WORD_DESC *word; /* The thing to test. */
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PATTERN_LIST *clauses; /* The clauses to test against, or NULL. */
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} CASE_COM;
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/* FOR command. */
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typedef struct for_com {
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int flags; /* See description of CMD flags. */
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WORD_DESC *name; /* The variable name to get mapped over. */
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WORD_LIST *map_list; /* The things to map over. This is never NULL. */
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COMMAND *action; /* The action to execute.
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During execution, NAME is bound to successive
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members of MAP_LIST. */
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} FOR_COM;
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/* IF command. */
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typedef struct if_com {
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int flags; /* See description of CMD flags. */
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COMMAND *test; /* Thing to test. */
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COMMAND *true_case; /* What to do if the test returned non-zero. */
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COMMAND *false_case; /* What to do if the test returned zero. */
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} IF_COM;
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/* WHILE command. */
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typedef struct while_com {
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int flags; /* See description of CMD flags. */
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COMMAND *test; /* Thing to test. */
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COMMAND *action; /* Thing to do while test is non-zero. */
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} WHILE_COM;
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/* The "simple" command. Just a collection of words and redirects. */
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typedef struct simple_com {
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int flags; /* See description of CMD flags. */
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WORD_LIST *words; /* The program name, the arguments,
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variable assignments, etc. */
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REDIRECT *redirects; /* Redirections to perform. */
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} SIMPLE_COM;
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/* The "function_def" command. This isn't really a command, but it is
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represented as such for now. If the function def appears within
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`(' `)' the parser tries to set the SUBSHELL bit of the command. That
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means that FUNCTION_DEF has to be run through the executor. Maybe this
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command should be defined in a subshell. Who knows or cares. */
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typedef struct function_def {
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int ignore; /* See description of CMD flags. */
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WORD_DESC *name; /* The name of the function. */
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COMMAND *command; /* The parsed execution tree. */
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} FUNCTION_DEF;
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/* A command that is `grouped' allows pipes to take effect over
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the entire command structure. */
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typedef struct group_com {
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int ignore; /* See description of CMD flags. */
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COMMAND *command;
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} GROUP_COM;
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/* Forward declarations of functions called by the grammer. */
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extern REDIRECT *make_redirection ();
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extern WORD_LIST *make_word_list ();
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extern WORD_DESC *make_word ();
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extern COMMAND
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*make_for_command (), *make_case_command (), *make_if_command (),
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*make_while_command (), *command_connect (), *make_simple_command (),
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*make_function_def (), *clean_simple_command (), *make_until_command (),
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*make_group_command ();
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extern PATTERN_LIST *make_pattern_list ();
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extern COMMAND *global_command, *copy_command ();
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extern char **shell_environment;
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extern WORD_LIST *rest_of_args;
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/* Generalized global variables. */
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extern int executing, login_shell;
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/* Structure to pass around that holds a bitmap of file descriptors
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to close, and the size of that structure. Used in execute_cmd.c. */
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struct fd_bitmap {
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long size;
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char *bitmap;
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};
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#define FD_BITMAP_SIZE 32
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