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