Provide setenv/unsetenv for environments lacking them. Bug 1578

[exim.git] / src / src / setenv.c

diff --git a/src/src/setenv.c b/src/src/setenv.c
new file mode 100644 (file)
index 0000000..6da56d5
--- /dev/null
+++ b/src/src/setenv.c
@@ -0,0 +1,55 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) Michael Haardt 2015 */
+/* Copyright (c) Jeremy Harris 2015 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+/* This module provides (un)setenv routines for those environments
+lacking them in libraries. */
+
+
+static int
+setenv(const char * name, const char * val, int overwrite)
+{
+uschar * s;
+if (Ustrchr(name, '=')) return -1;
+if (overwrite || !getenv(name))
+  putenv(CS string_copy_malloc(string_sprintf("%s=%s", name, val)));
+return 0;
+}
+
+static int
+unsetenv(const char *name)
+{
+size_t len;
+const char * end;
+char ** e;
+extern char ** environ;
+
+if (!name)
+  {
+  errno = EINVAL;
+  return -1;
+  }
+
+for (end = name; *end != '=' && *end; ) end++;
+len = end - name;
+  
+/* Find name in environment and move remaining variables down.
+Do not early-out in case there are duplicate names. */
+
+for (e = environ; *e; e++)
+  if (strncmp(*e, name, len) == 0 && (*e)[len] == '=')
+    {
+    char ** sp = e;
+    do *sp = sp[1]; while (*++sp);
+    }
+
+return 0;
+}
+
+/* vi: aw ai sw=2
+*/
+/* End of setenv.c */