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authorJim Meyering <jim@meyering.net>1992-11-01 05:44:29 +0000
committerJim Meyering <jim@meyering.net>1992-11-01 05:44:29 +0000
commitccbd1d7dc5189f4637468a8136f672e60ee0e531 (patch)
treef07938daa9443c4a699efa77d88eb9eb2c2e663b /lib/putenv.c
parent144b82c6c22abaa2a3247dc33b286662a7aa90d9 (diff)
downloadcoreutils-ccbd1d7dc5189f4637468a8136f672e60ee0e531.tar.xz
Initial revision
Diffstat (limited to 'lib/putenv.c')
-rw-r--r--lib/putenv.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/lib/putenv.c b/lib/putenv.c
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+++ b/lib/putenv.c
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+/* 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 <sys/types.h>
+#include <errno.h>
+#ifdef STDC_HEADERS
+#include <stdlib.h>
+#else
+extern int errno;
+#endif
+
+#if defined(STDC_HEADERS) || defined(USG)
+#include <string.h>
+#define index strchr
+#define bcopy(s, d, n) memcpy((d), (s), (n))
+#else /* not (STDC_HEADERS or USG) */
+#include <strings.h>
+#endif /* STDC_HEADERS or USG */
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#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;
+}