Add 'tmp/piss.c'

tmp/piss.c

@@ -0,0 +1,64 @@
+// https://stackoverflow.com/questions/40067878/write-program-that-pretends-to-be-a-tty
+#include <sysexits.h>
+#include <unistd.h>
+#include <util.h>
+
+pid_t child = 0;
+
+void sighandler(int signum) {
+  if (child > 0) {
+    killpg(child, signum);
+    exit(signum);
+  }
+}
+
+// Run a command in a pty.
+// Usage: /path/to/this/binary command to run
+int main(int argc, char *argv[]) {
+  if (argc < 2) {
+    return EX_USAGE;
+  }
+
+  int master;
+  child = forkpty(&master, NULL, NULL, NULL);
+
+  if (child == -1) {
+    perror("failed to fork pty");
+    return EX_OSERR;
+  }
+
+  if (child == 0) {
+    // we're in the child process, so replace it with the command
+    execvp(argv[1], argv + 1);
+    perror("failed to execute command");
+    return EX_OSERR;
+  }
+
+  // trap kill signals and forward them to child process
+  signal(SIGHUP, sighandler);
+  signal(SIGINT, sighandler);
+  signal(SIGTERM, sighandler);
+
+  const int buf_size = 1024;
+  char buf[buf_size];
+  fd_set fds;
+  ssize_t bytes_read;
+
+  // forward the output continuously
+  while (1) {
+    FD_ZERO(&fds);
+    FD_SET(master, &fds);
+
+    if (select(master + 1, &fds, NULL, NULL, NULL) > 0 && FD_ISSET(master, &fds)) {
+      bytes_read = read(master, buf, buf_size);
+      if (bytes_read <= 0) {
+        return EXIT_SUCCESS;
+      }
+
+      if (write(STDOUT_FILENO, buf, bytes_read) != bytes_read) {
+        perror("failed to write to stdout");
+        return EX_OSERR;
+      }
+    }
+  }
+}