From ccbd1d7dc5189f4637468a8136f672e60ee0e531 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Sun, 1 Nov 1992 05:44:29 +0000 Subject: Initial revision --- lib/putenv.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 lib/putenv.c (limited to 'lib/putenv.c') diff --git a/lib/putenv.c b/lib/putenv.c new file mode 100644 index 000000000..512878c47 --- /dev/null +++ b/lib/putenv.c @@ -0,0 +1,101 @@ +/* Copyright (C) 1991 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include +#include +#ifdef STDC_HEADERS +#include +#else +extern int errno; +#endif + +#if defined(STDC_HEADERS) || defined(USG) +#include +#define index strchr +#define bcopy(s, d, n) memcpy((d), (s), (n)) +#else /* not (STDC_HEADERS or USG) */ +#include +#endif /* STDC_HEADERS or USG */ + +#ifdef HAVE_UNISTD_H +#include +#endif + +#ifndef NULL +#define NULL 0 +#endif + +#if !__STDC__ +#define const +#endif + +extern char **environ; + +/* Put STRING, which is of the form "NAME=VALUE", in the environment. */ +int +putenv (string) + const char *string; +{ + char *name_end = index (string, '='); + register size_t size; + register char **ep; + + if (name_end == NULL) + { + /* Remove the variable from the environment. */ + size = strlen (string); + for (ep = environ; *ep != NULL; ++ep) + if (!strncmp (*ep, string, size) && (*ep)[size] == '=') + { + while (ep[1] != NULL) + { + ep[0] = ep[1]; + ++ep; + } + *ep = NULL; + return 0; + } + } + + size = 0; + for (ep = environ; *ep != NULL; ++ep) + if (!strncmp (*ep, string, name_end - string) && + (*ep)[name_end - string] == '=') + break; + else + ++size; + + if (*ep == NULL) + { + static char **last_environ = NULL; + char **new_environ = (char **) malloc ((size + 2) * sizeof (char *)); + if (new_environ == NULL) + return -1; + (void) bcopy ((char *) environ, (char *) new_environ, size * sizeof (char *)); + new_environ[size] = (char *) string; + new_environ[size + 1] = NULL; + if (last_environ != NULL) + free ((char *) last_environ); + last_environ = new_environ; + environ = new_environ; + } + else + *ep = (char *) string; + + return 0; +} -- cgit v1.2.3-54-g00ecf