Add exec and exec_always commands

1 files changed, 85 insertions, 0 deletions

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);
+}