1 files changed, 35 insertions, 0 deletions
diff --git a/test/test-interpose.c b/test/test-interpose.c
new file mode 100644
index 0000000..ea28abb
--- /dev/null
+++ b/test/test-interpose.c
@@ -0,0 +1,35 @@
+#include "substitute.h"
+
+#include <unistd.h>
+#include <stdio.h>
+#include <mach-o/dyld.h>
+#include <assert.h>
+
+static void *getpid_plus = (void *) getpid + 5;
+
+static pid_t (*old_getpid)();
+static pid_t my_getpid() {
+	return old_getpid() + 1;
+}
+static gid_t my_getgid() {
+	return 42;
+}
+
+int main() {
+	const char *self = _dyld_get_image_name(0);
+	void *handle = substitute_open_image(self);
+	assert(handle);
+	struct substitute_import_hook hooks[] = {
+		{"_getpid", my_getpid, &old_getpid},
+		{"_getgid", my_getgid, NULL},
+
+	};
+	pid_t (*gp)() = getpid_plus - 5;
+	printf("original pid: %d\n", (int) gp());
+	substitute_interpose_imports(handle, hooks, sizeof(hooks)/sizeof(*hooks), 0);
+	gp = getpid_plus - 5;
+	printf("new pid: %d\n", (int) gp());
+	printf("new gid: %d\n", (int) getgid());
+
+	substitute_close_image(handle);
+}