} else {
# endif
# if defined(__CYGWIN__) || defined(EPOC) || defined(SYMBIAN)
- setenv(nam, val, 1);
+# if defined(HAS_UNSETENV)
+ if (val == NULL) {
+ (void)unsetenv(nam);
+ } else {
+ (void)setenv(nam, val, 1);
+ }
+# else /* ! HAS_UNSETENV */
+ (void)setenv(nam, val, 1);
+# endif /* HAS_UNSETENV */
# else
- char *new_env;
- const int nlen = strlen(nam);
- int vlen;
- if (!val) {
- val = "";
- }
- vlen = strlen(val);
- new_env = (char*)safesysmalloc((nlen + vlen + 2) * sizeof(char));
- /* all that work just for this */
- my_setenv_format(new_env, nam, nlen, val, vlen);
- (void)putenv(new_env);
+# if defined(HAS_UNSETENV)
+ if (val == NULL) {
+ (void)unsetenv(nam);
+ } else {
+ int nlen = strlen(nam);
+ int vlen = strlen(val);
+ char *new_env =
+ (char*)safesysmalloc((nlen + vlen + 2) * sizeof(char));
+ my_setenv_format(new_env, nam, nlen, val, vlen);
+ (void)putenv(new_env);
+ }
+# else /* ! HAS_UNSETENV */
+ char *new_env;
+ int nlen = strlen(nam), vlen;
+ if (!val) {
+ val = "";
+ }
+ vlen = strlen(val);
+ new_env = (char*)safesysmalloc((nlen + vlen + 2) * sizeof(char));
+ /* all that work just for this */
+ my_setenv_format(new_env, nam, nlen, val, vlen);
+ (void)putenv(new_env);
+# endif /* HAS_UNSETENV */
# endif /* __CYGWIN__ */
#ifndef PERL_USE_SAFE_PUTENV
}