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 given name. The search paths for the executed
  28         file are paths specified in the PATH environment variable.
  29
  30     INPUTS
  31         file - Name of the file to execute.
  32         argv - Array of arguments given to main() function of the executed
  33         file.
  34
  35     RESULT
  36         Returns -1 and sets errno appropriately in case of error, otherwise
  37         doesn't return.
  38
  39     NOTES
  40
  41     EXAMPLE
  42
  43     BUGS
  44
  45     SEE ALSO
  46         execve(), execl(), execlp(), execv()
  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