Subversion Repositories SvarDOS

/* locates executable fname in path and fill res with result. returns 0 on success,

 * -1 on failed match and -2 on failed match + "don't even try with other paths"

 * extptr is filled with a ptr to the extension in fname (NULL if no extension) */

int lookup_cmd(char *res, const char *fname, const char *path, const char **extptr) {

  unsigned short lastbslash = 0;

  unsigned short i, len;

  unsigned char explicitpath = 0;

  /* does the original fname has an explicit path prefix or explicit ext? */

  *extptr = NULL;

  for (i = 0; fname[i] != 0; i++) {

    switch (fname[i]) {

      case ':':

      case '\\':

        explicitpath = 1;

        *extptr = NULL; /* extension is the last dot AFTER all path delimiters */

        break;

      case '.':

        *extptr = fname + i + 1;

        break;

    }

  }

  /* normalize filename */

  if (file_truename(fname, res) != 0) return(-2);

  /* printf("truename: %s\r\n", res); */

  /* figure out where the command starts and if it has an explicit extension */

  for (len = 0; res[len] != 0; len++) {

    switch (res[len]) {

      case '?':   /* abort on any wildcard character */

      case '*':

        return(-2);

      case '\\':

        lastbslash = len;

        break;

    }

  }

  /* printf("lastbslash=%u\r\n", lastbslash); */

  /* if no path prefix was found in fname (no colon or backslash) AND we have

   * a path arg, then assemble path+filename */

  if ((!explicitpath) && (path != NULL) && (path[0] != 0)) {

    i = strlen(path);

    if (path[i - 1] != '\\') i++; /* add a byte for inserting a bkslash after path */

    /* move the filename at the place where path will end */

    memmove(res + i, res + lastbslash + 1, len - lastbslash);

    /* copy path in front of the filename and make sure there is a bkslash sep */

    memmove(res, path, i);

    res[i - 1] = '\\';

  }

  /* if no extension was initially provided, try matching COM, EXE, BAT */

  if (*extptr == NULL) {

    const char *ext[] = {".COM", ".EXE", ".BAT", NULL};

    len = strlen(res);

    for (i = 0; ext[i] != NULL; i++) {

      strcpy(res + len, ext[i]);

      /* printf("? '%s'\r\n", res); */

      *extptr = ext[i] + 1;

      if (file_getattr(res) >= 0) return(0);

    }

  } else { /* try finding it as-is */

    /* printf("? '%s'\r\n", res); */

    if (file_getattr(res) >= 0) return(0);

  }

  /* not found */

  if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */

  return(-1);

}

/* fills fname with the path and filename to the linkfile related to the

 * executable link "linkname". returns 0 on success. */

int link_computefname(char *fname, const char *linkname, unsigned short env_seg) {

  unsigned short pathlen;

  /* fetch %DOSDIR% */

  pathlen = env_lookup_valcopy(fname, 128, env_seg, "DOSDIR");

  if (pathlen == 0) {

    outputnl("%DOSDIR% not defined");

    return(-1);

  }

  /* prep filename: %DOSDIR%\LINKS\PKG.LNK */

  if (fname[pathlen - 1] == '\\') pathlen--;

  sprintf(fname + pathlen, "\\LINKS\\%s.LNK", linkname);

  return(0);

}