78 lines
2.2 KiB
C
78 lines
2.2 KiB
C
/* RCS $Id: putenv.c,v 1.1.1.1 2000-09-22 15:33:34 hr Exp $
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--
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-- SYNOPSIS
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-- My own putenv for BSD like systems.
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--
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-- DESCRIPTION
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-- This originally came from MKS, but I rewrote it to fix a bug with
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-- replacing existing strings, probably never happened but the code
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-- was wrong nonetheless.
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--
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-- AUTHOR
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-- Dennis Vadura, dvadura@dmake.wticorp.com
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--
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-- WWW
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-- http://dmake.wticorp.com/
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--
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-- COPYRIGHT
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-- Copyright (c) 1996,1997 by WTI Corp. All rights reserved.
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--
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-- This program is NOT free software; you can redistribute it and/or
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-- modify it under the terms of the Software License Agreement Provided
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-- in the file <distribution-root>/readme/license.txt.
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--
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-- LOG
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-- Use cvs log to obtain detailed change logs.
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*/
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#include <stdio.h>
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#include <string.h>
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int
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putenv( str )/*
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===============
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Take a string of the form NAME=value and stick it into the environment.
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We do this by allocating a new set of pointers if we have to add a new
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string and by replacing an existing pointer if the value replaces the value
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of an existing string. */
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char *str;
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{
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extern char **environ; /* The current environment. */
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static char **ourenv = NULL; /* A new environment */
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register char **p;
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register char *q;
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int size;
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/* First search the current environment and see if we can replace a
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* string. */
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for( p=environ; *p; p++ ) {
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register char *s = str;
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for( q = *p; *q && *s && *s == *q; q++, s++ )
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if( *s == '=' ) {
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*p = str;
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return(0); /* replaced it so go away */
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}
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}
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/* Ok, can't replace a string so need to grow the environment. */
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size = p - environ + 2; /* size of new environment */
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/* size of old is size-1 */
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/* It's the first time, so allocate a new environment since we don't know
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* where the old one is comming from. */
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if( ourenv == NULL ) {
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if( (ourenv = (char **) malloc( sizeof(char *)*size )) == NULL )
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return(1);
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memcpy( (char *)ourenv, (char *)environ, (size-2)*sizeof(char *) );
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}
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else if( (ourenv = (char **)realloc( ourenv, size*sizeof(char *))) == NULL )
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return(1);
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ourenv[--size] = NULL;
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ourenv[--size] = str;
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environ = ourenv;
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return(0);
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}
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