usr/src/cmd/make/lib/vroot/setenv.cc

   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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 1994 Sun Microsystems, Inc. All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30
  31 extern  char    **environ;
  32
  33 static  short   setenv_made_new_vector= 0;
  34
  35 char *setenv(char *name, char *value)
  36 {       char *p= NULL, **q;
  37         int length= 0, vl;
  38
  39         if ((p= getenv(name)) == NULL) {        /* Allocate new vector */
  40                 for (q= environ; *q != NULL; q++, length++);
  41                 q= (char **)malloc((unsigned)(sizeof(char *)*(length+2)));
  42                 memcpy(((char *)q)+sizeof(char *), (char *)environ, sizeof(char *)*(length+1));
  43                 if (setenv_made_new_vector++)
  44                         free((char *)environ);
  45                 length= strlen(name);
  46                 environ= q;}
  47         else { /* Find old slot */
  48                 length= strlen(name);
  49                 for (q= environ; *q != NULL; q++)
  50                         if (!strncmp(*q, name, length))
  51                                 break;};
  52         vl= strlen(value);
  53         if (!p || (length+vl+1 > strlen(p)))
  54                 *q= p= (char *) malloc((unsigned)(length+vl+2));
  55         else
  56                 p= *q;
  57         (void)strcpy(p, name); p+= length;
  58         *p++= '=';
  59         (void)strcpy(p, value);
  60         return(value);
  61 }