lib/libspl/getexecname.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include <pthread.h>
  31 #include <limits.h>
  32
  33 const char *
  34 getexecname(void)
  35 {
  36         static char execname[PATH_MAX + 1] = "";
  37         static pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER;
  38         char *ptr = NULL;
  39         ssize_t rc;
  40
  41         (void) pthread_mutex_lock(&mtx);
  42
  43         if (strlen(execname) == 0) {
  44                 rc = readlink("/proc/self/exe",
  45                     execname, sizeof (execname) - 1);
  46                 if (rc == -1) {
  47                         execname[0] = '\0';
  48                 } else {
  49                         execname[rc] = '\0';
  50                         ptr = execname;
  51                 }
  52         } else {
  53                 ptr = execname;
  54         }
  55
  56         (void) pthread_mutex_unlock(&mtx);
  57         return (ptr);
  58 }