10Sstevel@tonic-gate /*
20Sstevel@tonic-gate * CDDL HEADER START
30Sstevel@tonic-gate *
40Sstevel@tonic-gate * The contents of this file are subject to the terms of the
50Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only
60Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance
70Sstevel@tonic-gate * with the License.
80Sstevel@tonic-gate *
90Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
100Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
110Sstevel@tonic-gate * See the License for the specific language governing permissions
120Sstevel@tonic-gate * and limitations under the License.
130Sstevel@tonic-gate *
140Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
150Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
160Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
170Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
180Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
190Sstevel@tonic-gate *
200Sstevel@tonic-gate * CDDL HEADER END
210Sstevel@tonic-gate */
220Sstevel@tonic-gate /*
230Sstevel@tonic-gate * Copyright 1987 Sun Microsystems, Inc. All rights reserved.
240Sstevel@tonic-gate * Use is subject to license terms.
250Sstevel@tonic-gate */
260Sstevel@tonic-gate
270Sstevel@tonic-gate /* Copyright (c) 1984 AT&T */
280Sstevel@tonic-gate /* All Rights Reserved */
290Sstevel@tonic-gate
30*722Smuffin #pragma ident "%Z%%M% %I% %E% SMI"
310Sstevel@tonic-gate
320Sstevel@tonic-gate /* LINTLIBRARY */
330Sstevel@tonic-gate /* putenv - change environment variables
34*722Smuffin *
35*722Smuffin * input - char *change = a pointer to a string of the form
36*722Smuffin * "name=value"
37*722Smuffin *
38*722Smuffin * output - 0, if successful
39*722Smuffin * 1, otherwise
40*722Smuffin */
410Sstevel@tonic-gate
42*722Smuffin #include <stdio.h>
43*722Smuffin #include <stdlib.h>
44*722Smuffin
450Sstevel@tonic-gate extern char **environ; /* pointer to enviroment */
46*722Smuffin static int reall; /* flag to reallocate space, if putenv is called
470Sstevel@tonic-gate more than once */
48*722Smuffin static int find(char *);
49*722Smuffin static int match(char *, char *);
500Sstevel@tonic-gate
510Sstevel@tonic-gate int
putenv(char * change)52*722Smuffin putenv(char *change)
530Sstevel@tonic-gate {
540Sstevel@tonic-gate char **newenv; /* points to new environment */
55*722Smuffin int which; /* index of variable to replace */
560Sstevel@tonic-gate
570Sstevel@tonic-gate if ((which = find(change)) < 0) {
580Sstevel@tonic-gate /* if a new variable */
590Sstevel@tonic-gate /* which is negative of table size, so invert and
600Sstevel@tonic-gate count new element */
610Sstevel@tonic-gate which = (-which) + 1;
620Sstevel@tonic-gate if (reall) {
630Sstevel@tonic-gate /* we have expanded environ before */
640Sstevel@tonic-gate newenv = (char **)realloc(environ,
650Sstevel@tonic-gate which*sizeof(char *));
66*722Smuffin if (newenv == NULL) return (-1);
670Sstevel@tonic-gate /* now that we have space, change environ */
680Sstevel@tonic-gate environ = newenv;
690Sstevel@tonic-gate } else {
700Sstevel@tonic-gate /* environ points to the original space */
710Sstevel@tonic-gate reall++;
720Sstevel@tonic-gate newenv = (char **)malloc(which*sizeof(char *));
73*722Smuffin if (newenv == NULL) return (-1);
740Sstevel@tonic-gate (void)memcpy((char *)newenv, (char *)environ,
750Sstevel@tonic-gate (int)(which*sizeof(char *)));
760Sstevel@tonic-gate environ = newenv;
770Sstevel@tonic-gate }
780Sstevel@tonic-gate environ[which-2] = change;
790Sstevel@tonic-gate environ[which-1] = NULL;
800Sstevel@tonic-gate } else {
810Sstevel@tonic-gate /* we are replacing an old variable */
820Sstevel@tonic-gate environ[which] = change;
830Sstevel@tonic-gate }
84*722Smuffin return (0);
850Sstevel@tonic-gate }
860Sstevel@tonic-gate
870Sstevel@tonic-gate /* find - find where s2 is in environ
880Sstevel@tonic-gate *
890Sstevel@tonic-gate * input - str = string of form name=value
900Sstevel@tonic-gate *
910Sstevel@tonic-gate * output - index of name in environ that matches "name"
920Sstevel@tonic-gate * -size of table, if none exists
930Sstevel@tonic-gate */
94*722Smuffin static int
find(char * str)95*722Smuffin find(char *str)
960Sstevel@tonic-gate {
97*722Smuffin int ct = 0; /* index into environ */
980Sstevel@tonic-gate
990Sstevel@tonic-gate while(environ[ct] != NULL) {
1000Sstevel@tonic-gate if (match(environ[ct], str) != 0)
101*722Smuffin return (ct);
1020Sstevel@tonic-gate ct++;
1030Sstevel@tonic-gate }
104*722Smuffin return (-(++ct));
1050Sstevel@tonic-gate }
1060Sstevel@tonic-gate /*
1070Sstevel@tonic-gate * s1 is either name, or name=value
1080Sstevel@tonic-gate * s2 is name=value
1090Sstevel@tonic-gate * if names match, return value of 1,
1100Sstevel@tonic-gate * else return 0
1110Sstevel@tonic-gate */
1120Sstevel@tonic-gate
113*722Smuffin static int
match(char * s1,char * s2)114*722Smuffin match(char *s1, char *s2)
1150Sstevel@tonic-gate {
1160Sstevel@tonic-gate while(*s1 == *s2++) {
1170Sstevel@tonic-gate if (*s1 == '=')
118*722Smuffin return (1);
1190Sstevel@tonic-gate s1++;
1200Sstevel@tonic-gate }
121*722Smuffin return (0);
1220Sstevel@tonic-gate }
123