2.11BSD#431 - /usr/src/lib/libc/gen/devname.c

   1: /*
   2:  * Copyright (c) 1989, 1993
   3:  *	The Regents of the University of California.  All rights reserved.
   4:  *
   5:  * Redistribution and use in source and binary forms, with or without
   6:  * modification, are permitted provided that the following conditions
   7:  * are met:
   8:  * 1. Redistributions of source code must retain the above copyright
   9:  *    notice, this list of conditions and the following disclaimer.
  10:  * 2. Redistributions in binary form must reproduce the above copyright
  11:  *    notice, this list of conditions and the following disclaimer in the
  12:  *    documentation and/or other materials provided with the distribution.
  13:  * 3. All advertising materials mentioning features or use of this software
  14:  *    must display the following acknowledgement:
  15:  *	This product includes software developed by the University of
  16:  *	California, Berkeley and its contributors.
  17:  * 4. Neither the name of the University nor the names of its contributors
  18:  *    may be used to endorse or promote products derived from this software
  19:  *    without specific prior written permission.
  20:  *
  21:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31:  * SUCH DAMAGE.
  32:  */
  33: 
  34: #if defined(LIBC_SCCS) && !defined(lint)
  35: static char sccsid[] = "@(#)devname.c	8.1.1 (2.11BSD GTE) 2/3/95";
  36: #endif /* LIBC_SCCS and not lint */
  37: 
  38: #include <sys/types.h>
  39: #include <ndbm.h>
  40: #include <fcntl.h>
  41: #include <paths.h>
  42: #include <stdio.h>
  43: 
  44: char *
  45: devname(dev, type)
  46:     dev_t dev;
  47:     mode_t type;
  48: {
  49:     struct {
  50:         mode_t type;
  51:         dev_t dev;
  52:     } bkey;
  53:     char    *devdb = _PATH_DEVDB;
  54:     static DBM *db;
  55:     static int failure;
  56:     datum data, key;
  57: 
  58:     if (!db && !failure &&
  59:         !(db = dbm_open(devdb, O_RDONLY, 0))) {
  60:         warn("warning: %s", devdb);
  61:         failure = 1;
  62:     }
  63:     if (failure)
  64:         return("??");
  65: 
  66:     /*
  67: 	 * Keys are a mode_t followed by a dev_t.  The former is the type of
  68: 	 * the file (mode & S_IFMT), the latter is the st_rdev field.  Be
  69: 	 * sure to clear any padding that may be found in bkey.
  70: 	 */
  71:     memset(&bkey, 0, sizeof(bkey));
  72:     bkey.dev = dev;
  73:     bkey.type = type;
  74:     key.dptr = (char *)&bkey;
  75:     key.dsize = sizeof(bkey);
  76:     data = dbm_fetch(db, key);
  77:     return(data.dptr == NULL ? "??" : (char *)data.dptr);
  78: }

Defined functions

Defined variables