win32: env.c code shrink and clarification

Use xasprintf() to create string in unsetenv().

Clarify when we're using WIN32 _putenv().

No change in functionality; saves 16 bytes.

1 files changed, 6 insertions, 7 deletions

diff --git a/win32/env.c b/win32/env.c
index 2837c0720..a7ab7851a 100644
--- a/win32/env.c
+++ b/win32/env.c
@@ -33,12 +33,12 @@ int setenv(const char *name, const char *value, int replace)
 }
 
 /*
- * Removing an environment variable with WIN32 putenv requires an argument
+ * Removing an environment variable with WIN32 _putenv requires an argument
  * like "NAME="; glibc omits the '='.  The implementations of unsetenv and
  * clearenv allow for this.
  *
  * It isn't possible to create an environment variable with an empty value
- * using WIN32 putenv.
+ * using WIN32 _putenv.
  */
 int unsetenv(const char *name)
 {
@@ -49,9 +49,8 @@ int unsetenv(const char *name)
                 return -1;
         }
 
-        envstr = xmalloc(strlen(name)+2);
-        strcat(strcpy(envstr, name), "=");
-        ret = putenv(envstr);
+        envstr = xasprintf("%s=", name);
+        ret = _putenv(envstr);
         free(envstr);
 
         return ret;
@@ -64,7 +63,7 @@ int clearenv(void)
         while ( environ && (envp=*environ) ) {
                 if ( (s=strchr(envp, '=')) != NULL ) {
                         name = xstrndup(envp, s-envp+1);
-                        if ( putenv(name) == -1 ) {
+                        if (_putenv(name) == -1) {
                                 free(name);
                                 return -1;
                         }
@@ -86,7 +85,7 @@ int mingw_putenv(const char *env)
         }
 
         if ( s[1] != '\0' ) {
-                return putenv(env);
+                return _putenv(env);
         }
 
         /* can't set empty value */