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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (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 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* NAME
* xsetenv, xgetenv, Xgetenv - manage an alternate environment space
*
* SYNOPSIS
* int ret = xsetenv(file)
* char *x = xgetenv("FOO");
* char *x = Xgetenv("FOO");
*
* DESCRIPTION
* xsetenv() reads the given file into an internal buffer
* and sets up an alternate environment.
*
* Return values: 1 - OKAY
* 0 - troubles reading the file
* -1 - troubles opening the file
*
* xgetenv() returns the environment value from the
* alternate environment.
*
* Return values: (char *)0 - no value for that variable
* pointer - the value
*
* Xgetenv() returns the environment value from the
* alternate environment.
*
* Return values: "" - no value for that variable
* pointer - the value
*
* LIMITATIONS
* Assumes the environment is < 5120 bytes, as in the UNIX
* System environment. Assumes < 512 lines in the file.
* These values may be adjusted below.
*/
#include <sys/types.h>
#include "libmail.h"
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#define MAXVARS 512
#define MAXENV 5120
static char **xenv = 0;
static char *(xenvptrs[MAXVARS]);
static char xbuf[MAXENV];
static void reduce(char *);
/*
* set up an environment buffer
* and the pointers into it
*/
int
xsetenv(char *xfile)
{
int envctr, infd;
ssize_t i, nread;
/* Open the file */
infd = open(xfile, O_RDONLY);
if (infd == -1) {
return (-1);
}
/* Read in the entire file. */
nread = read(infd, xbuf, sizeof (xbuf));
if (nread < 0) {
(void) close(infd);
return (0);
}
/*
* Set up pointers into the buffer.
* Replace \n with \0.
* Collapse white space around the = sign and at the
* beginning and end of the line.
*/
xenv = xenvptrs;
xenv[0] = &xbuf[0];
for (i = 0, envctr = 0; i < nread; i++) {
if (xbuf[i] == '\n') {
xbuf[i] = '\0';
reduce(xenv[envctr]);
xenv[++envctr] = &xbuf[i+1];
if (envctr == MAXVARS) {
break;
}
}
}
xenv[envctr] = 0;
(void) close(infd);
return (1);
}
/*
* Let getenv() do the dirty work
* of looking up the variable. We
* do this by temporarily resetting
* environ to point to the local area.
*/
char *
xgetenv(char *env)
{
extern char **environ;
char *ret, **svenviron = environ;
environ = xenv;
ret = getenv(env);
environ = svenviron;
return (ret);
}
/*
* Let xgetenv() do the dirty work
* of looking up the variable.
*/
char *
Xgetenv(char *env)
{
char *ret = xgetenv(env);
return (ret ? ret : "");
}
/*
* Remove the spaces within the environment variable.
* The variable can look like this:
*
* <sp1> variable <sp2> = <sp3> value <sp4> \0
*
* All spaces can be removed, except within
* the variable name and the value.
*/
static void
reduce(char *from)
{
char *to = from;
char *svfrom = from;
/* <sp1> */
while (*from &&isspace((int)*from))
from++;
/* variable */
while (*from && (*from != '=') && !isspace((int)*from))
*to++ = *from++;
/* <sp2> */
while (*from && isspace((int)*from))
from++;
/* = */
if (*from == '=')
*to++ = *from++;
/* <sp3> */
while (*from && isspace((int)*from))
from++;
/* value */
while (*from)
*to++ = *from++;
/* <sp4> */
while ((to > svfrom) && isspace((int)to[-1]))
to--;
*to = '\0';
}
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