chgenv.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Copyright (c) 1985 AT&T
* All Rights Reserved
*/
#ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.1 */
#include <stdio.h>
#include <fcntl.h>
#define LOOKING 1
#define SKIPPING 2
char *
chgenv(file, name, val)
char *file;
char *name;
char *val;
{
char inbuf[BUFSIZ];
char outbuf[BUFSIZ];
register char *p;
char *index;
register int c;
register int state;
register FILE *infp;
register FILE *outfp;
int len;
char *strnsave();
char *backslash();
FILE *tempfile();
if ((outfp = tempfile(NULL, "w+")) == NULL)
return NULL;
setbuf(outfp, outbuf);
if (val) {
fputs(name, outfp);
putc('=', outfp);
len = 2 * strlen(val);
fputs(p = backslash(strnsave(val, len), len), outfp);
free(p);
putc('\n', outfp);
}
if ((infp = fopen(file, "r+"))) {
setbuf(infp, inbuf);
state = LOOKING;
index = name;
for (c = getc(infp); c != EOF; c = getc(infp)) {
if (state == SKIPPING) {
if (c == '\n') {
state = LOOKING;
index = name;
}
continue;
}
if (state == LOOKING) {
/* if we are in name */
if (*index) {
if (c == *index) {
index++;
continue;
}
}
/* found name, look for "=" */
else if (c == '=') {
state = SKIPPING;
continue;
}
/* failure, copy line to outfile */
for (p = name; p < index; p++)
putc(*p, outfp);
state = 0;
}
if (c == '\n') {
state = LOOKING;
index = name;
}
putc(c, outfp);
}
fclose(infp);
}
{
register int fd;
register int n;
if ((fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, 0640)) >= 0) {
fseek(outfp, 0L, 0);
while ((n = fread(inbuf, 1, sizeof(inbuf), outfp)) > 0)
write(fd, inbuf, n);
close(fd);
}
else
val = NULL;
}
fclose(outfp);
return val;
}