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/*
* SCCS: @(#)putenv.c 1.9 (97/07/28)
*
* UniSoft Ltd., London, England
*
* (C) Copyright 1992 X/Open Company Limited
*
* All rights reserved. No part of this source code may be reproduced,
* stored in a retrieval system, or transmitted, in any form or by any
* means, electronic, mechanical, photocopying, recording or otherwise,
* except as stated in the end-user licence agreement, without the prior
* permission of the copyright owners.
*
* X/Open and the 'X' symbol are trademarks of X/Open Company Limited in
* the UK and other countries.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
/************************************************************************
SCCS: @(#)putenv.c 1.9 97/07/28 TETware release 3.3
NAME: putenv.c
PRODUCT: TETware
AUTHOR: Andrew Dingwall, UniSoft Ltd.
DATE CREATED: April 1992
DESCRIPTION:
environment manipulation function
MODIFICATIONS:
Andrew Dingwall, UniSoft Ltd., February 1993
allow user to modify environment between calls
Andrew Dingwall, UniSoft Ltd., July 1997
added support the MT DLL version of the C runtime support library
on Win32 systems
************************************************************************/
#include <stdio.h>
#include "dtmac.h"
#include "dtetlib.h"
/*
** tet_putenv() - add an environment string to the environment
**
** return 0 if successful or -1 on error
**
** this routine is here because not all systems have putenv(3)
*/
int tet_putenv(s)
char *s;
{
static char **env;
static int envlen;
register char *p1, *p2;
register char **ep1, **ep2;
extern char **environ;
/* see if the 'name' part is already in the environment
if so, make the ptr refer to the new string */
for (ep1 = environ; *ep1; ep1++) {
for (p1 = *ep1, p2 = s; *p1 && *p2; p1++, p2++)
if (*p1 != *p2 || *p1 == '=')
break;
if (*p1 == '=' && *p2 == '=') {
*ep1 = s;
return(0);
}
}
/* not there so:
see if we have been here before -
make ep2 point to the old environment space (if any);
allocate a new environment space */
ep2 = env;
if (BUFCHK((char **) &env, &envlen, (int) (((ep1 - environ) + 2) * sizeof *env)) < 0)
return(-1);
/* now make ep2 point to the end of the new environment,
copy in the old environment if env did not previously
refer to it */
if (ep2 && ep2 == environ)
ep2 = env + (ep1 - environ);
else
for (ep1 = environ, ep2 = env; *ep1; ep1++, ep2++)
*ep2 = *ep1;
/* add the new string to the end of the new environment */
*ep2++ = s;
*ep2 = (char *) 0;
environ = env;
return(0);
}
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