builtins/source.def

   1 This file is source.def, from which is created source.c.
   2 It implements the builtins "." and  "source" in Bash.
   3
   4 Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.
   5
   6 This file is part of GNU Bash, the Bourne Again SHell.
   7
   8 Bash is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 1, or (at your option) any later
  11 version.
  12
  13 Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License along
  19 with Bash; see the file COPYING.  If not, write to the Free Software
  20 Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22 $PRODUCES source.c
  23
  24 $BUILTIN source
  25 $FUNCTION source_builtin
  26 $SHORT_DOC source filename
  27 Read and execute commands from FILENAME and return.  The pathnames
  28 in $PATH are used to find the directory containing FILENAME.
  29 $END
  30 $BUILTIN .
  31 $DOCNAME dot
  32 $FUNCTION source_builtin
  33 $SHORT_DOC . filename
  34 Read and execute commands from FILENAME and return.  The pathnames
  35 in $PATH are used to find the directory containing FILENAME.
  36 $END
  37 /* source.c - Implements the `.' and `source' builtins. */
  38
  39 #include <sys/types.h>
  40 #include <sys/file.h>
  41 #include <errno.h>
  42
  43 #if defined (HAVE_STRING_H)
  44 #  include <string.h>
  45 #else /* !HAVE_STRING_H */
  46 #  include <strings.h>
  47 #endif /* !HAVE_STRING_H */
  48
  49 #include "../shell.h"
  50 #include "../posixstat.h"
  51 #include "../filecntl.h"
  52 #include "../execute_cmd.h"
  53
  54 /* Not all systems declare ERRNO in errno.h... and some systems #define it! */
  55 #if !defined (errno)
  56 extern int errno;
  57 #endif /* !errno */
  58
  59 /* Variables used here but defined in other files. */
  60 extern int return_catch_flag, return_catch_value;
  61 extern jmp_buf return_catch;
  62 extern int posixly_correct;
  63 extern int interactive, interactive_shell, last_command_exit_value;
  64
  65 /* How many `levels' of sourced files we have. */
  66 int sourcelevel = 0;
  67
  68 /* If this . script is supplied arguments, we save the dollar vars and
  69    replace them with the script arguments for the duration of the script's
  70    execution.  If the script does not change the dollar vars, we restore
  71    what we saved.  If the dollar vars are changed in the script, we leave
  72    the new values alone and free the saved values. */
  73 static void
  74 maybe_pop_dollar_vars ()
  75 {
  76   if (dollar_vars_changed ())
  77     {
  78       dispose_saved_dollar_vars ();
  79       set_dollar_vars_unchanged ();
  80     }
  81   else
  82     pop_dollar_vars ();
  83 }
  84
  85 /* Read and execute commands from the file passed as argument.  Guess what.
  86    This cannot be done in a subshell, since things like variable assignments
  87    take place in there.  So, I open the file, place it into a large string,
  88    close the file, and then execute the string. */
  89 source_builtin (list)
  90      WORD_LIST *list;
  91 {
  92   int result, return_val;
  93
  94   /* Assume the best. */
  95   result = EXECUTION_SUCCESS;
  96
  97   if (list)
  98     {
  99       char *string, *filename;
 100       struct stat finfo;
 101       int fd, tt;
 102
 103       filename = find_path_file (list->word->word);
 104       if (!filename)
 105         filename = savestring (list->word->word);
 106
 107       if (((fd = open (filename, O_RDONLY)) < 0) || (fstat (fd, &finfo) < 0))
 108         goto file_error_exit;
 109
 110       string = (char *)xmalloc (1 + (int)finfo.st_size);
 111       tt = read (fd, string, finfo.st_size);
 112       string[finfo.st_size] = '\0';
 113
 114       /* Close the open file, preserving the state of errno. */
 115       { int temp = errno; close (fd); errno = temp; }
 116
 117       if (tt != finfo.st_size)
 118         {
 119           free (string);
 120
 121         file_error_exit:
 122           file_error (filename);
 123           free (filename);
 124
 125           /* POSIX shells exit if non-interactive and file error. */
 126           if (posixly_correct && !interactive_shell)
 127             {
 128               last_command_exit_value = 1;
 129               longjmp (top_level, EXITPROG);
 130             }
 131
 132           return (EXECUTION_FAILURE);
 133         }
 134
 135       if (tt > 80)
 136         tt = 80;
 137
 138       if (check_binary_file ((unsigned char *)string, tt))
 139         {
 140           free (string);
 141           builtin_error ("%s: cannot execute binary file", filename);
 142           free (filename);
 143           return (EX_BINARY_FILE);
 144         }
 145
 146       begin_unwind_frame ("File Sourcing");
 147
 148       if (list->next)
 149         {
 150           push_dollar_vars ();
 151           add_unwind_protect ((Function *)maybe_pop_dollar_vars, (char *)NULL);
 152           remember_args (list->next, 1);
 153         }
 154
 155       unwind_protect_int (return_catch_flag);
 156       unwind_protect_jmp_buf (return_catch);
 157       unwind_protect_int (interactive);
 158       unwind_protect_int (sourcelevel);
 159       add_unwind_protect ((Function *)xfree, filename);
 160       interactive = 0;
 161       sourcelevel++;
 162
 163       set_dollar_vars_unchanged ();
 164
 165       return_catch_flag++;
 166       return_val = setjmp (return_catch);
 167
 168       if (return_val)
 169         parse_and_execute_cleanup ();
 170       else
 171         result = parse_and_execute (string, filename, -1);
 172
 173       run_unwind_frame ("File Sourcing");
 174
 175       /* If RETURN_VAL is non-zero, then we return the value given
 176          to return_builtin (), since that is how we got here. */
 177       if (return_val)
 178         result = return_catch_value;
 179     }
 180   else
 181     {
 182       builtin_error ("filename argument required");
 183       result = EXECUTION_FAILURE;
 184     }
 185   return (result);
 186 }