compiler/clib/execvp.c

   1 /*
   2     Copyright © 1995-2003, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     POSIX function execvp().
   6 */
   7
   8 #include <aros/debug.h>
   9
  10 #include <fcntl.h>
  11 #include <unistd.h>
  12 #include <errno.h>
  13 #include <stdlib.h>
  14
  15 /*****************************************************************************
  16
  17     NAME */
  18 #include <unistd.h>
  19
  20         int execvp(
  21
  22 /*  SYNOPSIS */
  23         const char *file,
  24         char *const argv[])
  25
  26 /*  FUNCTION
  27         Executes a file with specified arguments.
  28
  29     INPUTS
  30         file - Name of the file to execute.
  31         argv - Array of arguments given to main() function of the executed
  32         file.
  33
  34     RESULT
  35         0 in case of success. In case of failure errno is set appropriately
  36         and function returns -1.
  37
  38     NOTES
  39
  40     EXAMPLE
  41
  42     BUGS
  43         See execve documentation.
  44
  45     SEE ALSO
  46         execve()
  47
  48     INTERNALS
  49
  50 ******************************************************************************/
  51 {
  52     char *path = NULL, *path_item, *path_ptr;
  53     char default_path[] = ":/bin:/usr/bin";
  54     char *full_path;
  55     int saved_errno;
  56     int i;
  57
  58     if(index(file, '/') || index(file, ':'))
  59     {
  60         /* file argument is a path, don't search */
  61         return execve(file, argv, environ);
  62     }
  63
  64     /* argument is a file, search for this file in PATH variable entries */
  65     char *name = "PATH";
  66     if(environ)
  67     {
  68         for(i = 0; environ[i]; i++)
  69         {
  70             if(strncmp(environ[i], name, strlen(name)) == 0)
  71             {
  72                 path = &environ[i][strlen(name)+1];
  73                 break;
  74             }
  75         }
  76     }
  77
  78     if(!path)
  79         path = getenv("PATH");
  80
  81     if(!path)
  82         path = default_path;
  83     else
  84         path = strdup(path);
  85
  86     path_ptr = path;
  87
  88     while((path_item = strsep(&path_ptr, ",:")))
  89     {
  90         if(path_item[0] == '\0')
  91             path_item = ".";
  92
  93         if(full_path = malloc(strlen(path_item) + strlen(file) + 2))
  94         {
  95             full_path[0] = '\0';
  96             strcat(full_path, path_item);
  97             strcat(full_path, "/");
  98             strcat(full_path, file);
  99
 100             /* try executing execve with this path */
 101             if(execve(full_path, argv, environ) == 0)
 102             {
 103                 free(full_path);
 104                 return 0;
 105             }
 106             else
 107                 if(errno == EACCES)
 108                     saved_errno = EACCES;
 109             free(full_path);
 110         }
 111         else
 112         {
 113             saved_errno = ENOMEM;
 114             goto error;
 115         }
 116     }
 117
 118     /* set ENOENT error if there were errors other than EACCES */
 119     if(saved_errno != EACCES)
 120         saved_errno = ENOENT;
 121
 122 error:
 123     errno = saved_errno;
 124     return -1;
 125 } /* execvp() */
 126