Test the log buffers before running command

native/jni/utils/misc.c

@@ -245,9 +245,9 @@ void setup_sighandlers(void (*handler)(int)) {
    fd == NULL -> Ignore output
   *fd < 0     -> Open pipe and set *fd to the read end
   *fd >= 0    -> STDOUT (or STDERR) will be redirected to *fd
-  *cb         -> A callback function which runs after fork
+  *setenv     -> A callback function which sets up a vector of environment variables
 */
-static int v_exec_command(int err, int *fd, void (*setupenv)(struct vector*), const char *argv0, va_list argv) {
+int exec_array(int err, int *fd, void (*setenv)(struct vector *), char *const *argv) {
 	int pipefd[2], writeEnd = -1;
 
 	if (fd) {
@@ -260,20 +260,12 @@ static int v_exec_command(int err, int *fd, void (*setupenv)(struct vector*), co
 		}
 	}
 
-	// Collect va_list into vector
-	struct vector args;
-	vec_init(&args);
-	vec_push_back(&args, strdup(argv0));
-	for (void *arg = va_arg(argv, void*); arg; arg = va_arg(argv, void*))
-		vec_push_back(&args, strdup(arg));
-	vec_push_back(&args, NULL);
-
 	// Setup environment
 	char *const *envp;
 	struct vector env;
 	vec_init(&env);
-	if (setupenv) {
-		setupenv(&env);
+	if (setenv) {
+		setenv(&env);
 		envp = (char **) vec_entry(&env);
 	} else {
 		extern char **environ;
@@ -287,21 +279,34 @@ static int v_exec_command(int err, int *fd, void (*setupenv)(struct vector*), co
 			*fd = pipefd[0];
 			close(pipefd[1]);
 		}
-		vec_deep_destroy(&args);
 		vec_deep_destroy(&env);
 		return pid;
 	}
 
 	if (fd) {
 		xdup2(writeEnd, STDOUT_FILENO);
-		if (err) xdup2(writeEnd, STDERR_FILENO);
+		if (err)
+			xdup2(writeEnd, STDERR_FILENO);
 	}
 
-	execvpe(argv0, (char **) vec_entry(&args), envp);
-	PLOGE("execvpe %s", argv0);
+	execvpe(argv[0], argv, envp);
+	PLOGE("execvpe %s", argv[0]);
 	return -1;
 }
 
+static int v_exec_command(int err, int *fd, void (*setenv)(struct vector*), const char *argv0, va_list argv) {
+	// Collect va_list into vector
+	struct vector args;
+	vec_init(&args);
+	vec_push_back(&args, strdup(argv0));
+	for (void *arg = va_arg(argv, void*); arg; arg = va_arg(argv, void*))
+		vec_push_back(&args, strdup(arg));
+	vec_push_back(&args, NULL);
+	int pid = exec_array(err, fd, setenv, (char **) vec_entry(&args));
+	vec_deep_destroy(&args);
+	return pid;
+}
+
 int exec_command_sync(char *const argv0, ...) {
 	va_list argv;
 	va_start(argv, argv0);
@@ -314,10 +319,10 @@ int exec_command_sync(char *const argv0, ...) {
 	return WEXITSTATUS(status);
 }
 
-int exec_command(int err, int *fd, void (*setupenv)(struct vector*), const char *argv0, ...) {
+int exec_command(int err, int *fd, void (*setenv)(struct vector*), const char *argv0, ...) {
 	va_list argv;
 	va_start(argv, argv0);
-	int pid = v_exec_command(err, fd, setupenv, argv0, argv);
+	int pid = v_exec_command(err, fd, setenv, argv0, argv);
 	va_end(argv);
 	return pid;
 }

native/jni/utils/vector.c

@@ -3,6 +3,7 @@
 
 #include <stdlib.h>
 #include <string.h>
+#include <stdarg.h>
 
 #include "vector.h"
 
@@ -23,6 +24,15 @@ void vec_push_back(struct vector *v, void *p) {
 	++vec_size(v);
 }
 
+void vec_push_back_all(struct vector *v, void *p, ...) {
+	va_list argv;
+	va_start(argv, p);
+	vec_push_back(v, p);
+	for (void *arg = va_arg(argv, char*); arg; arg = va_arg(argv, char*))
+		vec_push_back(v, arg);
+	va_end(argv);
+}
+
 void *vec_pop_back(struct vector *v) {
 	void *ret = vec_entry(v)[vec_size(v) - 1];
 	--vec_size(v);
@@ -73,11 +83,9 @@ void vec_deep_destroy(struct vector *v) {
 	vec_destroy(v);
 }
 
-struct vector *vec_dup(struct vector *v) {
-	struct vector *ret = malloc(sizeof(*ret));
-	vec_size(ret) = vec_size(v);
-	vec_cap(ret) = vec_cap(v);
-	vec_entry(v) = malloc(sizeof(void*) * vec_cap(ret));
-	memcpy(vec_entry(ret), vec_entry(v), sizeof(void*) * vec_cap(ret));
-	return ret;
+void vec_dup(struct vector *v, struct vector *vv) {
+	vec_size(vv) = vec_size(v);
+	vec_cap(vv) = vec_cap(v);
+	vec_entry(vv) = malloc(sizeof(void*) * vec_cap(v));
+	memcpy(vec_entry(vv), vec_entry(v), sizeof(void*) * vec_cap(v));
 }