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authorKarl Berry <karl@freefriends.org>2006-01-17 21:41:51 +0000
committerKarl Berry <karl@freefriends.org>2006-01-17 21:41:51 +0000
commit487ca4806cc046076293cf6cc5fbba0db282bac7 (patch)
tree847b412ab5158dd7bdd7ed7e5a4cc3fbca94be32 /Build/source/texk/kpathsea/xputenv.c
parenta3d3111bfe26b8e5f5bc6049dfb2a4ca2edc7881 (diff)
texk 1
git-svn-id: svn://tug.org/texlive/trunk@1485 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Build/source/texk/kpathsea/xputenv.c')
-rw-r--r--Build/source/texk/kpathsea/xputenv.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/Build/source/texk/kpathsea/xputenv.c b/Build/source/texk/kpathsea/xputenv.c
new file mode 100644
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+++ b/Build/source/texk/kpathsea/xputenv.c
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+/* xputenv.c: set an environment variable without return.
+
+/*
+ * Copyright 2003-05 Olaf Weber.
+ * Copyright 1993-98 Karl Berry.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <kpathsea/config.h>
+
+#ifdef WIN32
+#include <stdlib.h>
+#else
+/* Avoid implicit declaration warning. But since some systems do
+ declare it, don't use a prototype, for fear of conflicts. */
+extern int putenv ();
+#endif /* not WIN32 */
+
+/* These record the strings we've set and have to keep around.
+ * This function can be called many times during a run, and this
+ * allows us to reclaim memory we allocated.
+ */
+static const char **saved_env;
+static int saved_count;
+
+/*
+ * We have different arguments from the "standard" function. A separate
+ * var and value tends to be much more practical.
+ *
+ * The standards for putenv are clear: put the passed string into the
+ * environment, and if you alter that string, the environment changes.
+ * Of course various implementations are broken in a number of ways,
+ * which include making copies of the passed string, and more.
+ */
+void
+xputenv(const char *var, const char *value)
+{
+ char *cur_item;
+ char *old_item;
+ char *new_item;
+ size_t var_lim;
+ int cur_loc;
+
+ /* kpse_debug2(KPSE_DEBUG_VARS, "kpse_putenv($%s,%s)", var, value); */
+
+ old_item = NULL;
+ cur_item = concat3(var, "=", value);
+ /* Include '=' in length. */
+ var_lim = strlen(var) + 1;
+
+ /* Have we stored something for this value already? */
+ for (cur_loc = 0; cur_loc != saved_count; ++cur_loc) {
+ if (strncmp(saved_env[cur_loc], cur_item, var_lim) == 0) {
+ /* Get the old value. We need this is case another part
+ * of the program didn't use us to change the environment.
+ */
+ old_item = getenv(var);
+ break;
+ }
+ }
+
+ if (old_item && strcmp(old_item, cur_item+var_lim) == 0) {
+ /* Set same value as is in environment, don't bother to set. */
+ free(cur_item);
+ return;
+ } else {
+ /* We set a different value. */
+ if (putenv(cur_item) < 0)
+ FATAL1("putenv(%s)", cur_item);
+ /* Get the new string. */
+ new_item = getenv(var);
+ if (new_item != cur_item+var_lim) {
+ /* Our new string isn't used, don't keep it around. */
+ free(cur_item);
+ return;
+ }
+ }
+
+ /* If we get here, it means getenv() returned a reference to cur_item.
+ * So we save cur_item, and free the old string we also owned.
+ */
+ if (cur_loc == saved_count) {
+ /* No old string. */
+ saved_count++;
+ saved_env = XRETALLOC(saved_env, saved_count, const char *);
+ } else {
+ /* We owned the old string. */
+ free(saved_env[cur_loc]);
+ }
+ saved_env[cur_loc] = cur_item;
+
+ return;
+}
+
+/* A special case for setting a variable to a numeric value
+ (specifically, KPATHSEA_DPI). We don't need to dynamically allocate
+ and free the string for the number, since it's saved as part of the
+ environment value. */
+
+void
+xputenv_int P2C(const_string, var_name, int, num)
+{
+ char str[MAX_INT_LENGTH];
+ sprintf (str, "%d", num);
+
+ xputenv (var_name, str);
+}