Untitled

void _unix_get_executable_name(char *output, int size)
{
   #ifdef ALLEGRO_HAVE_SV_PROCFS
      struct prpsinfo psinfo;
      int fd;
   #endif
   #if defined ALLEGRO_HAVE_SV_PROCFS || defined ALLEGRO_SYS_GETEXECNAME
      char *s;
   #endif
   char linkname[1024];
   char filename[1024];
   struct stat finfo;
   FILE *pipe;
   pid_t pid;
   int len;

   #ifdef ALLEGRO_HAVE_GETEXECNAME
      s = getexecname();
      if (s) {
         if (s[0] == '/') {   /* Absolute path */
            do_uconvert (s, U_ASCII, output, U_CURRENT, size);
            return;
         }
         else {               /* Not an absolute path */
            if (_find_executable_file(s, output, size))
               return;
         }
      }
      s = NULL;
   #endif

   /* We need the PID in order to query procfs */
   pid = getpid();

   /* Try a Linux-like procfs */
   /* get symolic link to executable from proc fs */
   sprintf (linkname, "/proc/%d/exe", pid);
   if (stat (linkname, &finfo) == 0) {
      len = readlink (linkname, filename, sizeof(filename)-1);
      if (len>-1) {
	 filename[len] = '\0';

	 do_uconvert (filename, U_ASCII, output, U_CURRENT, size);
	 return;
      }
   }

   /* Use System V procfs calls if available */
   #ifdef ALLEGRO_HAVE_SV_PROCFS
      sprintf (linkname, "/proc/%d/exe", pid);
      fd = open(linkname, O_RDONLY);
      if (!fd == -1) {
         ioctl(fd, PIOCPSINFO, &psinfo);
         close(fd);

         /* Use argv[0] directly if we can */
      #ifdef ALLEGRO_HAVE_PROCFS_ARGCV
	 if (psinfo.pr_argv && psinfo.pr_argc) {
	    if (_find_executable_file(psinfo.pr_argv[0], output, size))
	       return;
	 }
	 else
      #endif
	 {
	    /* Emulate it */
	    /* We use the pr_psargs field to find argv[0]
	     * This is better than using the pr_fname field because we need
	     * the additional path information that may be present in argv[0]
	     */

	    /* Skip other args */
	    s = strchr(psinfo.pr_psargs, ' ');
	    if (s) s[0] = '\0';
	    if (_find_executable_file(psinfo.pr_psargs, output, size))
	       return;
	 }

         /* Try the pr_fname just for completeness' sake if argv[0] fails */
         if (_find_executable_file(psinfo.pr_fname, output, size))
            return;
      }
   #endif

   /* Last resort: try using the output of the ps command to at least find */
   /* the name of the file if not the full path */
   uszprintf (linkname, sizeof(linkname), "ps -p %d", pid);
   do_uconvert (linkname, U_CURRENT, filename, U_ASCII, size);
   pipe = popen(filename, "r");
   if (pipe) {
      /* The first line of output is a header */
      fgets(linkname, sizeof(linkname), pipe);

      /* The information we want is in the last column; find it */
      len = strlen(linkname);
      while (linkname[len] != ' ' && linkname[len] != '\t')
         len--;

      /* The second line contains the info we want */
      fgets(linkname, sizeof(linkname), pipe);
      pclose(pipe);

      /* Treat special cases: filename between [] and - for login shell */
      if (linkname[len] == '-')
         len++;

      if (linkname[len] == '[' && linkname[strlen(linkname)] == ']') {
         len++;
         linkname[strlen(linkname)] = '\0';
      }

      /* Now, the filename should be in the last column */
      _al_sane_strncpy (filename, linkname+len+1, strlen(linkname)-len+1);

      if (_find_executable_file(filename, output, size))
         return;

      /* Just return the output from ps... */
      do_uconvert (filename, U_ASCII, output, U_CURRENT, size);
      return;
   }

#ifdef ALLEGRO_WITH_MAGIC_MAIN
   /* Try the captured argv[0] */
   if (_find_executable_file(__crt0_argv[0], output, size))
      return;
#endif

   /* Give up; return empty string */
   do_uconvert ("", U_ASCII, output, U_CURRENT, size);
}