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-rw-r--r--attach.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/attach.c b/attach.c
new file mode 100644
index 0000000..e318b89
--- /dev/null
+++ b/attach.c
@@ -0,0 +1,75 @@
+#define _GNU_SOURCE
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/wait.h>
+
+int main(int argc, char *argv[]) {
+ int fd;
+ const char *tty_path;
+ const char *tty_path_env;
+ pid_t pid;
+
+ fprintf(stderr, "%i\n", argc);
+ tty_path_env = getenv("TAKETTY_PTY");
+ if (argc <= 1 || (!strcmp(argv[1], "-") && !tty_path_env)) {
+ fprintf(stderr, "Usage: %s (PATH|-)\n", argv[0]);
+ fprintf(stderr, "Or set TAKETTY_PTY environment variable\n");
+ exit(1);
+ }
+
+ tty_path = argv[1];
+ if (!strcmp(argv[1], "-")) {
+ tty_path = tty_path_env;
+ }
+
+ pid = fork();
+ if (pid < 0) {
+ perror("fork");
+ exit(1);
+ }
+
+ if (pid > 0) {
+ int status;
+ waitpid(pid, &status, 0);
+ exit(WIFEXITED(status) ? WEXITSTATUS(status) : 1);
+ }
+
+ if (setsid() < 0) {
+ perror("setsid");
+ exit(1);
+ }
+
+ fd = open(tty_path, O_RDWR);
+ if (fd < 0) {
+ perror("open tty");
+ exit(1);
+ }
+
+ if (ioctl(fd, TIOCSCTTY, 0) < 0) {
+ perror("ioctl TIOCSCTTY");
+ exit(1);
+ }
+
+ if (dup2(fd, STDIN_FILENO) < 0 ||
+ dup2(fd, STDOUT_FILENO) < 0 ||
+ dup2(fd, STDERR_FILENO) < 0) {
+ perror("dup2");
+ exit(1);
+ }
+
+ if (fd > STDERR_FILENO) {
+ close(fd);
+ }
+
+ if (argc > 2) {
+ execvp(argv[2], &argv[2]);
+ perror("execvp");
+ exit(1);
+ }
+
+ return 0;
+}