1 files changed, 53 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/env/putenv.c b/libc-top-half/musl/src/env/putenv.c
new file mode 100644
index 0000000..0d59895
--- /dev/null
+++ b/libc-top-half/musl/src/env/putenv.c
@@ -0,0 +1,53 @@
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static void dummy(char *old, char *new) {}
+weak_alias(dummy, __env_rm_add);
+
+int __putenv(char *s, size_t l, char *r)
+{
+#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
+	size_t i=0;
+	if (__environ) {
+		for (char **e = __environ; *e; e++, i++)
+			if (!strncmp(s, *e, l+1)) {
+				char *tmp = *e;
+				*e = s;
+				__env_rm_add(tmp, r);
+				return 0;
+			}
+	}
+	static char **oldenv;
+	char **newenv;
+	if (__environ == oldenv) {
+		newenv = realloc(oldenv, sizeof *newenv * (i+2));
+		if (!newenv) goto oom;
+	} else {
+		newenv = malloc(sizeof *newenv * (i+2));
+		if (!newenv) goto oom;
+		if (i) memcpy(newenv, __environ, sizeof *newenv * i);
+		free(oldenv);
+	}
+	newenv[i] = s;
+	newenv[i+1] = 0;
+	__environ = oldenv = newenv;
+	if (r) __env_rm_add(0, r);
+	return 0;
+oom:
+	free(r);
+	return -1;
+}
+
+int putenv(char *s)
+{
+	size_t l = __strchrnul(s, '=') - s;
+	if (!l || !s[l]) return unsetenv(s);
+	return __putenv(s, l, 0);
+}