427 lines
		
	
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			427 lines
		
	
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * sh-i18n--envsubst.c - a stripped-down version of gettext's envsubst(1)
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|  *
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|  * Copyright (C) 2010 Ævar Arnfjörð Bjarmason
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|  *
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|  * This is a modified version of
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|  * 67d0871a8c:gettext-runtime/src/envsubst.c from the gettext.git
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|  * repository. It has been stripped down to only implement the
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|  * envsubst(1) features that we need in the git-sh-i18n fallbacks.
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|  *
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|  * The "Close standard error" part in main() is from
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|  * 8dac033df0:gnulib-local/lib/closeout.c. The copyright notices for
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|  * both files are reproduced immediately below.
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|  */
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| 
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| #include "git-compat-util.h"
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| #include "trace2.h"
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| 
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| /* Substitution of environment variables in shell format strings.
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|    Copyright (C) 2003-2007 Free Software Foundation, Inc.
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|    Written by Bruno Haible <bruno@clisp.org>, 2003.
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| 
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|    This program is free software; you can redistribute it and/or modify
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|    it under the terms of the GNU General Public License as published by
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|    the Free Software Foundation; either version 2, or (at your option)
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|    any later version.
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| 
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|    This program is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|    GNU General Public License for more details.
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| 
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|    You should have received a copy of the GNU General Public License
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|    along with this program; if not, see <http://www.gnu.org/licenses/>.  */
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| 
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| /* closeout.c - close standard output and standard error
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|    Copyright (C) 1998-2007 Free Software Foundation, Inc.
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| 
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|    This program is free software; you can redistribute it and/or modify
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|    it under the terms of the GNU General Public License as published by
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|    the Free Software Foundation; either version 2, or (at your option)
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|    any later version.
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| 
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|    This program is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|    GNU General Public License for more details.
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| 
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|    You should have received a copy of the GNU General Public License
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|    along with this program; if not, see <http://www.gnu.org/licenses/>.  */
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| 
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| #include <errno.h>
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <string.h>
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| 
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| /* If true, substitution shall be performed on all variables.  */
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| static unsigned short int all_variables;
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| 
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| /* Forward declaration of local functions.  */
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| static void print_variables (const char *string);
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| static void note_variables (const char *string);
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| static void subst_from_stdin (void);
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| 
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| int
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| cmd_main (int argc, const char *argv[])
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| {
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|   /* Default values for command line options.  */
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|   /* unsigned short int show_variables = 0; */
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| 
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|   trace2_cmd_name("sh-i18n--envsubst");
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| 
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|   switch (argc)
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| 	{
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| 	case 1:
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| 	  error ("we won't substitute all variables on stdin for you");
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| 	  break;
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| 	  /*
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| 	  all_variables = 1;
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|       subst_from_stdin ();
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| 	  */
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| 	case 2:
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| 	  /* echo '$foo and $bar' | git sh-i18n--envsubst --variables '$foo and $bar' */
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| 	  all_variables = 0;
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| 	  note_variables (argv[1]);
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|       subst_from_stdin ();
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| 	  break;
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| 	case 3:
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| 	  /* git sh-i18n--envsubst --variables '$foo and $bar' */
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| 	  if (strcmp(argv[1], "--variables"))
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| 		error ("first argument must be --variables when two are given");
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| 	  /* show_variables = 1; */
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|       print_variables (argv[2]);
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| 	  break;
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| 	default:
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| 	  error ("too many arguments");
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| 	  break;
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| 	}
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| 
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|   /* Close standard error.  This is simpler than fwriteerror_no_ebadf, because
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|      upon failure we don't need an errno - all we can do at this point is to
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|      set an exit status.  */
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|   errno = 0;
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|   if (ferror (stderr) || fflush (stderr))
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|     {
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|       fclose (stderr);
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|       exit (EXIT_FAILURE);
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|     }
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|   if (fclose (stderr) && errno != EBADF)
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|     exit (EXIT_FAILURE);
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| 
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|   exit (EXIT_SUCCESS);
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| }
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| 
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| /* Parse the string and invoke the callback each time a $VARIABLE or
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|    ${VARIABLE} construct is seen, where VARIABLE is a nonempty sequence
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|    of ASCII alphanumeric/underscore characters, starting with an ASCII
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|    alphabetic/underscore character.
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|    We allow only ASCII characters, to avoid dependencies w.r.t. the current
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|    encoding: While "${\xe0}" looks like a variable access in ISO-8859-1
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|    encoding, it doesn't look like one in the BIG5, BIG5-HKSCS, GBK, GB18030,
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|    SHIFT_JIS, JOHAB encodings, because \xe0\x7d is a single character in these
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|    encodings.  */
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| static void
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| find_variables (const char *string,
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| 		void (*callback) (const char *var_ptr, size_t var_len))
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| {
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|   for (; *string != '\0';)
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|     if (*string++ == '$')
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|       {
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| 	const char *variable_start;
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| 	const char *variable_end;
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| 	unsigned short int valid;
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| 	char c;
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| 
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| 	if (*string == '{')
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| 	  string++;
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| 
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| 	variable_start = string;
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| 	c = *string;
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| 	if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')
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| 	  {
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| 	    do
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| 	      c = *++string;
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| 	    while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')
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| 		   || (c >= '0' && c <= '9') || c == '_');
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| 	    variable_end = string;
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| 
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| 	    if (variable_start[-1] == '{')
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| 	      {
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| 		if (*string == '}')
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| 		  {
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| 		    string++;
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| 		    valid = 1;
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| 		  }
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| 		else
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| 		  valid = 0;
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| 	      }
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| 	    else
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| 	      valid = 1;
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| 
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| 	    if (valid)
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| 	      callback (variable_start, variable_end - variable_start);
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| 	  }
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|       }
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| }
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| 
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| 
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| /* Print a variable to stdout, followed by a newline.  */
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| static void
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| print_variable (const char *var_ptr, size_t var_len)
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| {
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|   fwrite (var_ptr, var_len, 1, stdout);
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|   putchar ('\n');
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| }
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| 
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| /* Print the variables contained in STRING to stdout, each one followed by a
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|    newline.  */
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| static void
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| print_variables (const char *string)
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| {
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|   find_variables (string, &print_variable);
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| }
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| 
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| 
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| /* Type describing list of immutable strings,
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|    implemented using a dynamic array.  */
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| typedef struct string_list_ty string_list_ty;
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| struct string_list_ty
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| {
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|   const char **item;
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|   size_t nitems;
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|   size_t nitems_max;
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| };
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| 
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| /* Initialize an empty list of strings.  */
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| static inline void
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| string_list_init (string_list_ty *slp)
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| {
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|   slp->item = NULL;
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|   slp->nitems = 0;
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|   slp->nitems_max = 0;
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| }
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| 
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| /* Append a single string to the end of a list of strings.  */
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| static inline void
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| string_list_append (string_list_ty *slp, const char *s)
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| {
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|   /* Grow the list.  */
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|   if (slp->nitems >= slp->nitems_max)
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|     {
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|       slp->nitems_max = slp->nitems_max * 2 + 4;
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|       REALLOC_ARRAY(slp->item, slp->nitems_max);
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|     }
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| 
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|   /* Add the string to the end of the list.  */
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|   slp->item[slp->nitems++] = s;
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| }
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| 
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| /* Compare two strings given by reference.  */
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| static int
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| cmp_string (const void *pstr1, const void *pstr2)
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| {
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|   const char *str1 = *(const char **)pstr1;
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|   const char *str2 = *(const char **)pstr2;
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| 
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|   return strcmp (str1, str2);
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| }
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| 
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| /* Sort a list of strings.  */
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| static inline void
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| string_list_sort (string_list_ty *slp)
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| {
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|   QSORT(slp->item, slp->nitems, cmp_string);
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| }
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| 
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| /* Test whether a sorted string list contains a given string.  */
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| static int
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| sorted_string_list_member (const string_list_ty *slp, const char *s)
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| {
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|   size_t j1, j2;
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| 
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|   j1 = 0;
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|   j2 = slp->nitems;
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|   if (j2 > 0)
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|     {
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|       /* Binary search.  */
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|       while (j2 - j1 > 1)
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| 	{
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| 	  /* Here we know that if s is in the list, it is at an index j
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| 	     with j1 <= j < j2.  */
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| 	  size_t j = j1 + ((j2 - j1) >> 1);
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| 	  int result = strcmp (slp->item[j], s);
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| 
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| 	  if (result > 0)
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| 	    j2 = j;
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| 	  else if (result == 0)
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| 	    return 1;
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| 	  else
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| 	    j1 = j + 1;
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| 	}
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|       if (j2 > j1)
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| 	if (strcmp (slp->item[j1], s) == 0)
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| 	  return 1;
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|     }
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|   return 0;
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| }
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| 
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| 
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| /* Set of variables on which to perform substitution.
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|    Used only if !all_variables.  */
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| static string_list_ty variables_set;
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| 
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| /* Adds a variable to variables_set.  */
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| static void
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| note_variable (const char *var_ptr, size_t var_len)
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| {
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|   char *string = xmemdupz (var_ptr, var_len);
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| 
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|   string_list_append (&variables_set, string);
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| }
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| 
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| /* Stores the variables occurring in the string in variables_set.  */
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| static void
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| note_variables (const char *string)
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| {
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|   string_list_init (&variables_set);
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|   find_variables (string, ¬e_variable);
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|   string_list_sort (&variables_set);
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| }
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| 
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| 
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| static int
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| do_getc (void)
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| {
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|   int c = getc (stdin);
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| 
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|   if (c == EOF)
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|     {
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|       if (ferror (stdin))
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| 	error ("error while reading standard input");
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|     }
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| 
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|   return c;
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| }
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| 
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| static inline void
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| do_ungetc (int c)
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| {
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|   if (c != EOF)
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|     ungetc (c, stdin);
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| }
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| 
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| /* Copies stdin to stdout, performing substitutions.  */
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| static void
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| subst_from_stdin (void)
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| {
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|   static char *buffer;
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|   static size_t bufmax;
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|   static size_t buflen;
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|   int c;
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| 
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|   for (;;)
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|     {
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|       c = do_getc ();
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|       if (c == EOF)
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| 	break;
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|       /* Look for $VARIABLE or ${VARIABLE}.  */
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|       if (c == '$')
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| 	{
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| 	  unsigned short int opening_brace = 0;
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| 	  unsigned short int closing_brace = 0;
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| 
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| 	  c = do_getc ();
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| 	  if (c == '{')
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| 	    {
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| 	      opening_brace = 1;
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| 	      c = do_getc ();
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| 	    }
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| 	  if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')
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| 	    {
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| 	      unsigned short int valid;
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| 
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| 	      /* Accumulate the VARIABLE in buffer.  */
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| 	      buflen = 0;
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| 	      do
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| 		{
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| 		  if (buflen >= bufmax)
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| 		    {
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| 		      bufmax = 2 * bufmax + 10;
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| 		      buffer = xrealloc (buffer, bufmax);
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| 		    }
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| 		  buffer[buflen++] = c;
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| 
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| 		  c = do_getc ();
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| 		}
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| 	      while ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')
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| 		     || (c >= '0' && c <= '9') || c == '_');
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| 
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| 	      if (opening_brace)
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| 		{
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| 		  if (c == '}')
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| 		    {
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| 		      closing_brace = 1;
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| 		      valid = 1;
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| 		    }
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| 		  else
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| 		    {
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| 		      valid = 0;
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| 		      do_ungetc (c);
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| 		    }
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| 		}
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| 	      else
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| 		{
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| 		  valid = 1;
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| 		  do_ungetc (c);
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| 		}
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| 
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| 	      if (valid)
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| 		{
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| 		  /* Terminate the variable in the buffer.  */
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| 		  if (buflen >= bufmax)
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| 		    {
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| 		      bufmax = 2 * bufmax + 10;
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| 		      buffer = xrealloc (buffer, bufmax);
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| 		    }
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| 		  buffer[buflen] = '\0';
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| 
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| 		  /* Test whether the variable shall be substituted.  */
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| 		  if (!all_variables
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| 		      && !sorted_string_list_member (&variables_set, buffer))
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| 		    valid = 0;
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| 		}
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| 
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| 	      if (valid)
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| 		{
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| 		  /* Substitute the variable's value from the environment.  */
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| 		  const char *env_value = getenv (buffer);
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| 
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| 		  if (env_value != NULL)
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| 		    fputs (env_value, stdout);
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| 		}
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| 	      else
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| 		{
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| 		  /* Perform no substitution at all.  Since the buffered input
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| 		     contains no other '$' than at the start, we can just
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| 		     output all the buffered contents.  */
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| 		  putchar ('$');
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| 		  if (opening_brace)
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| 		    putchar ('{');
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| 		  fwrite (buffer, buflen, 1, stdout);
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| 		  if (closing_brace)
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| 		    putchar ('}');
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| 		}
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| 	    }
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| 	  else
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| 	    {
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| 	      do_ungetc (c);
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| 	      putchar ('$');
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| 	      if (opening_brace)
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| 		putchar ('{');
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| 	    }
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| 	}
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|       else
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| 	putchar (c);
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|     }
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| }
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