From 514c819ff98d72880c5b7e0beb7bd9ca866bc1ad Mon Sep 17 00:00:00 2001
From: emersion <contact@emersion.fr>
Date: Mon, 4 Dec 2017 22:43:49 +0100
Subject: [PATCH] Add exec and exec_always commands

---
 sway/commands.c             |  2 +
 sway/commands/exec.c        | 16 +++++++
 sway/commands/exec_always.c | 85 +++++++++++++++++++++++++++++++++++++
 sway/meson.build            |  2 +
 4 files changed, 105 insertions(+)
 create mode 100644 sway/commands/exec.c
 create mode 100644 sway/commands/exec_always.c

diff --git a/sway/commands.c b/sway/commands.c
index 94a45253..5fdcdbb6 100644
--- a/sway/commands.c
+++ b/sway/commands.c
@@ -90,6 +90,8 @@ struct cmd_results *add_color(const char *name, char *buffer, const char *color)
 
 /* Keep alphabetized */
 static struct cmd_handler handlers[] = {
+	{ "exec", cmd_exec },
+	{ "exec_always", cmd_exec_always },
 	{ "exit", cmd_exit },
 };
 
diff --git a/sway/commands/exec.c b/sway/commands/exec.c
new file mode 100644
index 00000000..dd71500a
--- /dev/null
+++ b/sway/commands/exec.c
@@ -0,0 +1,16 @@
+#include <string.h>
+#include "sway/commands.h"
+#include "log.h"
+#include "stringop.h"
+
+struct cmd_results *cmd_exec(int argc, char **argv) {
+	// TODO: config
+	/*if (!config->active) return cmd_results_new(CMD_DEFER, "exec", NULL);
+	if (config->reloading) {
+		char *args = join_args(argv, argc);
+		sway_log(L_DEBUG, "Ignoring 'exec %s' due to reload", args);
+		free(args);
+		return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+	}*/
+	return cmd_exec_always(argc, argv);
+}
diff --git a/sway/commands/exec_always.c b/sway/commands/exec_always.c
new file mode 100644
index 00000000..0a252e7b
--- /dev/null
+++ b/sway/commands/exec_always.c
@@ -0,0 +1,85 @@
+#define _XOPEN_SOURCE 500
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include "sway/commands.h"
+#include "sway/workspace.h"
+#include "sway/container.h"
+#include "log.h"
+#include "stringop.h"
+
+struct cmd_results *cmd_exec_always(int argc, char **argv) {
+	struct cmd_results *error = NULL;
+	// TODO: config
+	//if (!config->active) return cmd_results_new(CMD_DEFER, NULL, NULL);
+	if ((error = checkarg(argc, "exec_always", EXPECTED_MORE_THAN, 0))) {
+		return error;
+	}
+
+	char *tmp = NULL;
+	if (strcmp((char*)*argv, "--no-startup-id") == 0) {
+		sway_log(L_INFO, "exec switch '--no-startup-id' not supported, ignored.");
+		if ((error = checkarg(argc - 1, "exec_always", EXPECTED_MORE_THAN, 0))) {
+			return error;
+		}
+
+		tmp = join_args(argv + 1, argc - 1);
+	} else {
+		tmp = join_args(argv, argc);
+	}
+
+	// Put argument into cmd array
+	char cmd[4096];
+	strncpy(cmd, tmp, sizeof(cmd));
+	cmd[sizeof(cmd) - 1] = 0;
+	free(tmp);
+	sway_log(L_DEBUG, "Executing %s", cmd);
+
+	int fd[2];
+	if (pipe(fd) != 0) {
+		sway_log(L_ERROR, "Unable to create pipe for fork");
+	}
+
+	pid_t pid;
+	pid_t *child = malloc(sizeof(pid_t)); // malloc'd so that Linux can avoid copying the process space
+	if (!child) {
+		return cmd_results_new(CMD_FAILURE, "exec_always", "Unable to allocate child pid");
+	}
+	// Fork process
+	if ((pid = fork()) == 0) {
+		// Fork child process again
+		setsid();
+		if ((*child = fork()) == 0) {
+			execl("/bin/sh", "/bin/sh", "-c", cmd, (void *)NULL);
+			// Not reached
+		}
+		close(fd[0]);
+		ssize_t s = 0;
+		while ((size_t)s < sizeof(pid_t)) {
+			s += write(fd[1], ((uint8_t *)child) + s, sizeof(pid_t) - s);
+		}
+		close(fd[1]);
+		_exit(0); // Close child process
+	} else if (pid < 0) {
+		free(child);
+		return cmd_results_new(CMD_FAILURE, "exec_always", "fork() failed");
+	}
+	close(fd[1]); // close write
+	ssize_t s = 0;
+	while ((size_t)s < sizeof(pid_t)) {
+		s += read(fd[0], ((uint8_t *)child) + s, sizeof(pid_t) - s);
+	}
+	close(fd[0]);
+	// cleanup child process
+	wait(0);
+	if (*child > 0) {
+		sway_log(L_DEBUG, "Child process created with pid %d", *child);
+		// TODO: add PID to active workspace
+	} else {
+		free(child);
+	}
+
+	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+}
diff --git a/sway/meson.build b/sway/meson.build
index 9f92f5d1..b224f15f 100644
--- a/sway/meson.build
+++ b/sway/meson.build
@@ -3,6 +3,8 @@ sway_sources = files(
 	'server.c',
 	'commands.c',
 	'commands/exit.c',
+	'commands/exec.c',
+	'commands/exec_always.c',
 	'ipc-json.c',
 	'ipc-server.c',
 	'desktop/output.c',