usr/src/lib/libbc/libc/gen/common/getcwd.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 1989 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984 AT&T */
  28 /*        All Rights Reserved   */
  29 #pragma ident   "%Z%%M% %I%     %E% SMI"  /* from S5R2 1.2 */
  30
  31 /*LINTLIBRARY*/
  32 /*
  33  * Library routine to GET the Current Working Directory.
  34  * arg1 is a pointer to a character buffer into which the
  35  * path name of the current directory is placed by the
  36  * subroutine.  arg1 may be zero, in which case the
  37  * subroutine will call malloc to get the required space.
  38  * arg2 is the length of the buffer space for the path-name.
  39  * If the actual path-name is longer than (arg2-2), or if
  40  * the value of arg2 is not at least 3, the subroutine will
  41  * return a value of zero, with errno set as appropriate.
  42  */
  43
  44 #include <stdio.h>
  45 #include <sys/errno.h>
  46
  47 extern FILE *popen();
  48 extern char *malloc(), *fgets(), *strchr();
  49 extern int errno, pclose();
  50
  51 char *
  52 getcwd(arg1, arg2)
  53 char    *arg1;
  54 int     arg2;
  55 {
  56         FILE    *pipe;
  57         char    *trm;
  58
  59         if(arg2 <= 0) {
  60                 errno = EINVAL;
  61                 return(0);
  62         }
  63         if(arg1 == 0)
  64                 if((arg1 = malloc((unsigned)arg2)) == 0) {
  65                         errno = ENOMEM;
  66                         return(0);
  67                 }
  68         errno = 0;
  69         if((pipe = popen("pwd", "r")) == 0)
  70                 return(0);
  71         (void) fgets(arg1, arg2, pipe);
  72         (void) pclose(pipe);
  73         trm = strchr(arg1, '\0');
  74         if(*(trm-1) != '\n') {
  75                 errno = ERANGE;
  76                 return(0);
  77         }
  78         *(trm-1) = '\0';
  79         return(arg1);
  80 }