subst.c

android-w.song.android.widget

/* subst.c -- The part of the shell that does parameter, command, arithmetic,
   and globbing substitutions. */

/* ``Have a little faith, there's magic in the night.  You ain't a
     beauty, but, hey, you're alright.'' */

/* Copyright (C) 1987-2010 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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "config.h"

#include "bashtypes.h"
#include <stdio.h>
#include "chartypes.h"
#if defined (HAVE_PWD_H)
#  include <pwd.h>
#endif
#include <signal.h>
#include <errno.h>

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif

#include "bashansi.h"
#include "posixstat.h"
#include "bashintl.h"

#include "shell.h"
#include "parser.h"
#include "flags.h"
#include "jobs.h"
#include "execute_cmd.h"
#include "filecntl.h"
#include "trap.h"
#include "pathexp.h"
#include "mailcheck.h"

#include "shmbutil.h"
#include "typemax.h"

#include "builtins/getopt.h"
#include "builtins/common.h"

#include "builtins/builtext.h"

#include <tilde/tilde.h>
#include <glob/strmatch.h>

#if !defined (errno)
extern int errno;
#endif /* !errno */

/* The size that strings change by. */
#define DEFAULT_INITIAL_ARRAY_SIZE 112
#define DEFAULT_ARRAY_SIZE 128

/* Variable types. */
#define VT_VARIABLE	0
#define VT_POSPARMS	1
#define VT_ARRAYVAR	2
#define VT_ARRAYMEMBER	3
#define VT_ASSOCVAR	4

#define VT_STARSUB	128	/* $* or ${array[*]} -- used to split */

/* Flags for quoted_strchr */
#define ST_BACKSL	0x01
#define ST_CTLESC	0x02
#define ST_SQUOTE	0x04	/* unused yet */
#define ST_DQUOTE	0x08	/* unused yet */

/* Flags for the `pflags' argument to param_expand() */
#define PF_NOCOMSUB	0x01	/* Do not perform command substitution */
#define PF_IGNUNBOUND	0x02	/* ignore unbound vars even if -u set */
#define PF_NOSPLIT2	0x04	/* same as W_NOSPLIT2 */

/* These defs make it easier to use the editor. */
#define LBRACE		'{'
#define RBRACE		'}'
#define LPAREN		'('
#define RPAREN		')'

#if defined (HANDLE_MULTIBYTE)
#define WLPAREN		L'('
#define WRPAREN		L')'
#endif

/* Evaluates to 1 if C is one of the shell's special parameters whose length
   can be taken, but is also one of the special expansion characters. */
#define VALID_SPECIAL_LENGTH_PARAM(c) \
  ((c) == '-' || (c) == '?' || (c) == '#')

/* Evaluates to 1 if C is one of the shell's special parameters for which an
   indirect variable reference may be made. */
#define VALID_INDIR_PARAM(c) \
  ((posixly_correct == 0 && (c) == '#') || (posixly_correct == 0 && (c) == '?') || (c) == '@' || (c) == '*')

/* Evaluates to 1 if C is one of the OP characters that follows the parameter
   in ${parameter[:]OPword}. */
#define VALID_PARAM_EXPAND_CHAR(c) (sh_syntaxtab[(unsigned char)c] & CSUBSTOP)

/* Evaluates to 1 if this is one of the shell's special variables. */
#define SPECIAL_VAR(name, wi) \
 ((DIGIT (*name) && all_digits (name)) || \
      (name[1] == '\0' && (sh_syntaxtab[(unsigned char)*name] & CSPECVAR)) || \
      (wi && name[2] == '\0' && VALID_INDIR_PARAM (name[1])))

/* An expansion function that takes a string and a quoted flag and returns
   a WORD_LIST *.  Used as the type of the third argument to
   expand_string_if_necessary(). */
typedef WORD_LIST *EXPFUNC __P((char *, int));

/* Process ID of the last command executed within command substitution. */
pid_t last_command_subst_pid = NO_PID;
pid_t current_command_subst_pid = NO_PID;

/* Variables used to keep track of the characters in IFS. */
SHELL_VAR *ifs_var;
char *ifs_value;
unsigned char ifs_cmap[UCHAR_MAX + 1];

#if defined (HANDLE_MULTIBYTE)
unsigned char ifs_firstc[MB_LEN_MAX];
size_t ifs_firstc_len;
#else
unsigned char ifs_firstc;
#endif

/* Sentinel to tell when we are performing variable assignments preceding a
   command name and putting them into the environment.  Used to make sure
   we use the temporary environment when looking up variable values. */
int assigning_in_environment;

/* Used to hold a list of variable assignments preceding a command.  Global
   so the SIGCHLD handler in jobs.c can unwind-protect it when it runs a
   SIGCHLD trap and so it can be saved and restored by the trap handlers. */
WORD_LIST *subst_assign_varlist = (WORD_LIST *)NULL;

/* Extern functions and variables from different files. */
extern int last_command_exit_value, last_command_exit_signal;
extern int subshell_environment, line_number;
extern int subshell_level, parse_and_execute_level, sourcelevel;
extern int eof_encountered;
extern int return_catch_flag, return_catch_value;
extern pid_t dollar_dollar_pid;
extern int posixly_correct;
extern char *this_command_name;
extern struct fd_bitmap *current_fds_to_close;
extern int wordexp_only;
extern int expanding_redir;
extern int tempenv_assign_error;

#if !defined (HAVE_WCSDUP) && defined (HANDLE_MULTIBYTE)
extern wchar_t *wcsdup __P((const wchar_t *));
#endif

/* Non-zero means to allow unmatched globbed filenames to expand to
   a null file. */
int allow_null_glob_expansion;

/* Non-zero means to throw an error when globbing fails to match anything. */
int fail_glob_expansion;

#if 0
/* Variables to keep track of which words in an expanded word list (the
   output of expand_word_list_internal) are the result of globbing
   expansions.  GLOB_ARGV_FLAGS is used by execute_cmd.c.
   (CURRENTLY UNUSED). */
char *glob_argv_flags;
static int glob_argv_flags_size;
#endif

static WORD_LIST expand_word_error, expand_word_fatal;
static WORD_DESC expand_wdesc_error, expand_wdesc_fatal;
static char expand_param_error, expand_param_fatal;
static char extract_string_error, extract_string_fatal;

/* Tell the expansion functions to not longjmp back to top_level on fatal
   errors.  Enabled when doing completion and prompt string expansion. */
static int no_longjmp_on_fatal_error = 0;

/* Set by expand_word_unsplit; used to inhibit splitting and re-joining
   $* on $IFS, primarily when doing assignment statements. */
static int expand_no_split_dollar_star = 0;

/* A WORD_LIST of words to be expanded by expand_word_list_internal,
   without any leading variable assignments. */
static WORD_LIST *garglist = (WORD_LIST *)NULL;

static char *quoted_substring __P((char *, int, int));
static int quoted_strlen __P((char *));
static char *quoted_strchr __P((char *, int, int));

static char *expand_string_if_necessary __P((char *, int, EXPFUNC *));
static inline char *expand_string_to_string_internal __P((char *, int, EXPFUNC *));
static WORD_LIST *call_expand_word_internal __P((WORD_DESC *, int, int, int *, int *));
static WORD_LIST *expand_string_internal __P((char *, int));
static WORD_LIST *expand_string_leave_quoted __P((char *, int));
static WORD_LIST *expand_string_for_rhs __P((char *, int, int *, int *));

static WORD_LIST *list_quote_escapes __P((WORD_LIST *));
static char *make_quoted_char __P((int));
static WORD_LIST *quote_list __P((WORD_LIST *));

static int unquoted_substring __P((char *, char *));
static int unquoted_member __P((int, char *));

#if defined (ARRAY_VARS)
static SHELL_VAR *do_compound_assignment __P((char *, char *, int));
#endif
static int do_assignment_internal __P((const WORD_DESC *, int));

static char *string_extract_verbatim __P((char *, size_t, int *, char *, int));
static char *string_extract __P((char *, int *, char *, int));
static char *string_extract_double_quoted __P((char *, int *, int));
static inline char *string_extract_single_quoted __P((char *, int *));
static inline int skip_single_quoted __P((const char *, size_t, int));
static int skip_double_quoted __P((char *, size_t, int));
static char *extract_delimited_string __P((char *, int *, char *, char *, char *, int));
static char *extract_dollar_brace_string __P((char *, int *, int, int));
static int skip_matched_pair __P((const char *, int, int, int, int));

static char *pos_params __P((char *, int, int, int));

static unsigned char *mb_getcharlens __P((char *, int));

static char *remove_upattern __P((char *, char *, int));
#if defined (HANDLE_MULTIBYTE) 
static wchar_t *remove_wpattern __P((wchar_t *, size_t, wchar_t *, int));
#endif
static char *remove_pattern __P((char *, char *, int));

static int match_upattern __P((char *, char *, int, char **, char **));
#if defined (HANDLE_MULTIBYTE)
static int match_wpattern __P((wchar_t *, char **, size_t, wchar_t *, int, char **, char **));
#endif
static int match_pattern __P((char *, char *, int, char **, char **));
static int getpatspec __P((int, char *));
static char *getpattern __P((char *, int, int));
static char *variable_remove_pattern __P((char *, char *, int, int));
static char *list_remove_pattern __P((WORD_LIST *, char *, int, int, int));
static char *parameter_list_remove_pattern __P((int, char *, int, int));
#ifdef ARRAY_VARS
static char *array_remove_pattern __P((SHELL_VAR *, char *, int, char *, int));
#endif
static char *parameter_brace_remove_pattern __P((char *, char *, int, char *, int, int, int));

static char *process_substitute __P((char *, int));

static char *read_comsub __P((int, int, int *));

#ifdef ARRAY_VARS
static arrayind_t array_length_reference __P((char *));
#endif

static int valid_brace_expansion_word __P((char *, int));
static int chk_atstar __P((char *, int, int *, int *));
static int chk_arithsub __P((const char *, int));

static WORD_DESC *parameter_brace_expand_word __P((char *, int, int, int, arrayind_t *));
static WORD_DESC *parameter_brace_expand_indir __P((char *, int, int, int *, int *));
static WORD_DESC *parameter_brace_expand_rhs __P((char *, char *, int, int, int *, int *));
static void parameter_brace_expand_error __P((char *, char *));

static int valid_length_expression __P((char *));
static intmax_t parameter_brace_expand_length __P((char *));

static char *skiparith __P((char *, int));
static int verify_substring_values __P((SHELL_VAR *, char *, char *, int, intmax_t *, intmax_t *));
static int get_var_and_type __P((char *, char *, arrayind_t, int, int, SHELL_VAR **, char **));
static char *mb_substring __P((char *, int, int));
static char *parameter_brace_substring __P((char *, char *, int, char *, int, int));

static int shouldexp_replacement __P((char *));

static char *pos_params_pat_subst __P((char *, char *, char *, int));

static char *parameter_brace_patsub __P((char *, char *, int, char *, int, int));

static char *pos_params_casemod __P((char *, char *, int, int));
static char *parameter_brace_casemod __P((char *, char *, int, int, char *, int, int));

static WORD_DESC *parameter_brace_expand __P((char *, int *, int, int, int *, int *));
static WORD_DESC *param_expand __P((char *, int *, int, int *, int *, int *, int *, int));

static WORD_LIST *expand_word_internal __P((WORD_DESC *, int, int, int *, int *));

static WORD_LIST *word_list_split __P((WORD_LIST *));

static void exp_jump_to_top_level __P((int));

static WORD_LIST *separate_out_assignments __P((WORD_LIST *));
static WORD_LIST *glob_expand_word_list __P((WORD_LIST *, int));
#ifdef BRACE_EXPANSION
static WORD_LIST *brace_expand_word_list __P((WORD_LIST *, int));
#endif
#if defined (ARRAY_VARS)
static int make_internal_declare __P((char *, char *));
#endif
static WORD_LIST *shell_expand_word_list __P((WORD_LIST *, int));
static WORD_LIST *expand_word_list_internal __P((WORD_LIST *, int));

/* **************************************************************** */
/*								    */
/*			Utility Functions			    */
/*								    */
/* **************************************************************** */

#if defined (DEBUG)
void
dump_word_flags (flags)
     int flags;
{
  int f;

  f = flags;
  fprintf (stderr, "%d -> ", f);
  if (f & W_ASSIGNASSOC)
    {
      f &= ~W_ASSIGNASSOC;
      fprintf (stderr, "W_ASSIGNASSOC%s", f ? "|" : "");
    }
  if (f & W_HASCTLESC)
    {
      f &= ~W_HASCTLESC;
      fprintf (stderr, "W_HASCTLESC%s", f ? "|" : "");
    }
  if (f & W_NOPROCSUB)
    {
      f &= ~W_NOPROCSUB;
      fprintf (stderr, "W_NOPROCSUB%s", f ? "|" : "");
    }
  if (f & W_DQUOTE)
    {
      f &= ~W_DQUOTE;
      fprintf (stderr, "W_DQUOTE%s", f ? "|" : "");
    }
  if (f & W_HASQUOTEDNULL)
    {
      f &= ~W_HASQUOTEDNULL;
      fprintf (stderr, "W_HASQUOTEDNULL%s", f ? "|" : "");
    }
  if (f & W_ASSIGNARG)
    {
      f &= ~W_ASSIGNARG;
      fprintf (stderr, "W_ASSIGNARG%s", f ? "|" : "");
    }
  if (f & W_ASSNBLTIN)
    {
      f &= ~W_ASSNBLTIN;
      fprintf (stderr, "W_ASSNBLTIN%s", f ? "|" : "");
    }
  if (f & W_COMPASSIGN)
    {
      f &= ~W_COMPASSIGN;
      fprintf (stderr, "W_COMPASSIGN%s", f ? "|" : "");
    }
  if (f & W_NOEXPAND)
    {
      f &= ~W_NOEXPAND;
      fprintf (stderr, "W_NOEXPAND%s", f ? "|" : "");
    }
  if (f & W_ITILDE)
    {
      f &= ~W_ITILDE;
      fprintf (stderr, "W_ITILDE%s", f ? "|" : "");
    }
  if (f & W_NOTILDE)
    {
      f &= ~W_NOTILDE;
      fprintf (stderr, "W_NOTILDE%s", f ? "|" : "");
    }
  if (f & W_ASSIGNRHS)
    {
      f &= ~W_ASSIGNRHS;
      fprintf (stderr, "W_ASSIGNRHS%s", f ? "|" : "");
    }
  if (f & W_NOCOMSUB)
    {
      f &= ~W_NOCOMSUB;
      fprintf (stderr, "W_NOCOMSUB%s", f ? "|" : "");
    }
  if (f & W_DOLLARSTAR)
    {
      f &= ~W_DOLLARSTAR;
      fprintf (stderr, "W_DOLLARSTAR%s", f ? "|" : "");
    }
  if (f & W_DOLLARAT)
    {
      f &= ~W_DOLLARAT;
      fprintf (stderr, "W_DOLLARAT%s", f ? "|" : "");
    }
  if (f & W_TILDEEXP)
    {
      f &= ~W_TILDEEXP;
      fprintf (stderr, "W_TILDEEXP%s", f ? "|" : "");
    }
  if (f & W_NOSPLIT2)
    {
      f &= ~W_NOSPLIT2;
      fprintf (stderr, "W_NOSPLIT2%s", f ? "|" : "");
    }
  if (f & W_NOGLOB)
    {
      f &= ~W_NOGLOB;
      fprintf (stderr, "W_NOGLOB%s", f ? "|" : "");
    }
  if (f & W_NOSPLIT)
    {
      f &= ~W_NOSPLIT;
      fprintf (stderr, "W_NOSPLIT%s", f ? "|" : "");
    }
  if (f & W_GLOBEXP)
    {
      f &= ~W_GLOBEXP;
      fprintf (stderr, "W_GLOBEXP%s", f ? "|" : "");
    }
  if (f & W_ASSIGNMENT)
    {
      f &= ~W_ASSIGNMENT;
      fprintf (stderr, "W_ASSIGNMENT%s", f ? "|" : "");
    }
  if (f & W_QUOTED)
    {
      f &= ~W_QUOTED;
      fprintf (stderr, "W_QUOTED%s", f ? "|" : "");
    }
  if (f & W_HASDOLLAR)
    {
      f &= ~W_HASDOLLAR;
      fprintf (stderr, "W_HASDOLLAR%s", f ? "|" : "");
    }
  fprintf (stderr, "\n");
  fflush (stderr);
}
#endif

#ifdef INCLUDE_UNUSED
static char *
quoted_substring (string, start, end)
     char *string;
     int start, end;
{
  register int len, l;
  register char *result, *s, *r;

  len = end - start;

  /* Move to string[start], skipping quoted characters. */
  for (s = string, l = 0; *s && l < start; )
    {
      if (*s == CTLESC)
	{
	  s++;
	  continue;
	}
      l++;
      if (*s == 0)
	break;
    }

  r = result = (char *)xmalloc (2*len + 1);      /* save room for quotes */

  /* Copy LEN characters, including quote characters. */
  s = string + l;
  for (l = 0; l < len; s++)
    {
      if (*s == CTLESC)
	*r++ = *s++;
      *r++ = *s;
      l++;
      if (*s == 0)
	break;
    }
  *r = '\0';
  return result;
}
#endif