1 files changed, 35 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/env/unsetenv.c b/libc-top-half/musl/src/env/unsetenv.c
new file mode 100644
index 0000000..40f0eea
--- /dev/null
+++ b/libc-top-half/musl/src/env/unsetenv.c
@@ -0,0 +1,35 @@
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+
+static void dummy(char *old, char *new) {}
+weak_alias(dummy, __env_rm_add);
+
+int unsetenv(const char *name)
+{
+	size_t l = __strchrnul(name, '=') - name;
+	if (!l || name[l]) {
+		errno = EINVAL;
+		return -1;
+	}
+#ifdef __wasilibc_unmodified_upstream // Lazy environment variable init.
+#else
+// This specialized header is included within the function body to arranges for
+// the environment variables to be lazily initialized. It redefined `__environ`,
+// so don't remove or reorder it with respect to other code.
+#include "wasi/libc-environ-compat.h"
+#endif
+	if (__environ) {
+		char **e = __environ, **eo = e;
+		for (; *e; e++)
+			if (!strncmp(name, *e, l) && l[*e] == '=')
+				__env_rm_add(*e, 0);
+			else if (eo != e)
+				*eo++ = *e;
+			else
+				eo++;
+		if (eo != e) *eo = 0;
+	}
+	return 0;
+}