diff options
Diffstat (limited to 'tests')
| -rw-r--r-- | tests/ptyx.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/tests/ptyx.c b/tests/ptyx.c new file mode 100644 index 0000000..4d89581 --- /dev/null +++ b/tests/ptyx.c @@ -0,0 +1,256 @@ +// Copyright © Tavian Barnes <tavianator@tavianator.com> +// SPDX-License-Identifier: 0BSD + +/** + * Execute a command in a pseudo-terminal. + * + * $ ptyx [-w WIDTH] [-h HEIGHT] [--] COMMAND [ARGS...] + */ + +#include "bfs.h" +#include "bfstd.h" + +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/wait.h> +#include <termios.h> +#include <unistd.h> + +#if __has_include(<stropts.h>) +# include <stropts.h> +#endif + +#if __sun +/** + * Push a STREAMS module, if it's not already there. + * + * See https://www.illumos.org/issues/9042. + */ +static int i_push(int fd, const char *name) { + int ret = ioctl(fd, I_FIND, name); + if (ret < 0) { + return ret; + } else if (ret == 0) { + return ioctl(fd, I_PUSH, name); + } else { + return 0; + } +} +#endif + +int main(int argc, char *argv[]) { + const char *cmd = argc > 0 ? argv[0] : "ptyx"; + +/** Report an error message and exit. */ +#define die(...) die_(__VA_ARGS__, ) + +#define die_(format, ...) \ + do { \ + fprintf(stderr, "%s: " format "%s", cmd, __VA_ARGS__ "\n"); \ + exit(EXIT_FAILURE); \ + } while (0) + +/** Report an error code and exit. */ +#define edie(...) edie_(__VA_ARGS__, ) + +#define edie_(format, ...) \ + do { \ + fprintf(stderr, "%s: " format ": %s\n", cmd, __VA_ARGS__ errstr()); \ + exit(EXIT_FAILURE); \ + } while (0) + + long width = -1; + long height = -1; + + // Parse the command line + int c; + while (c = getopt(argc, argv, "+:w:h:"), c != -1) { + switch (c) { + case 'w': + if (xstrtol(optarg, NULL, 10, &width) != 0) { + edie("Bad width '%s'", optarg); + } else if (width < 0 || width > (long)USHRT_MAX) { + die("Bad width '%s'", optarg); + } + break; + case 'h': + if (xstrtol(optarg, NULL, 10, &height) != 0) { + edie("Bad height '%s'", optarg); + } else if (height < 0 || height > (long)USHRT_MAX) { + die("Bad height '%s'", optarg); + } + break; + case ':': + die("Missing argument to -%c", optopt); + case '?': + die("Unrecognized option -%c", optopt); + } + } + + if (optind >= argc) { + die("Missing command"); + } + char **args = argv + optind; + + // Create a new pty, and set it up + int ptm = posix_openpt(O_RDWR | O_NOCTTY); + if (ptm < 0) { + edie("posix_openpt()"); + } + if (grantpt(ptm) != 0) { + edie("grantpt()"); + } + if (unlockpt(ptm) != 0) { + edie("unlockpt()"); + } + + // Get the subsidiary device path + char *name = ptsname(ptm); + if (!name) { + edie("ptsname()"); + } + + // Open the subsidiary device + int pts = open(name, O_RDWR | O_NOCTTY); + if (pts < 0) { + edie("%s", name); + } + +#if __sun + // On Solaris/illumos, a pty doesn't behave like a terminal until we + // push some STREAMS modules (see ptm(4D), ptem(4M), ldterm(4M)). + if (i_push(pts, "ptem") != 0) { + die("ioctl(I_PUSH, ptem)"); + } + if (i_push(pts, "ldterm") != 0) { + die("ioctl(I_PUSH, ldterm)"); + } +#endif + + // A new pty starts at 0x0, which is not very useful. Instead, grab the + // default size from the current controlling terminal, if possible. + if (width < 0 || height < 0) { + int tty = open_cterm(O_RDONLY | O_CLOEXEC); + if (tty >= 0) { + struct winsize ws; + if (xtcgetwinsize(tty, &ws) != 0) { + edie("tcgetwinsize()"); + } + if (width < 0) { + width = ws.ws_col; + } + if (height < 0) { + height = ws.ws_row; + } + xclose(tty); + } + } + + // Get the current pty size + struct winsize ws; + if (xtcgetwinsize(pts, &ws) != 0) { + edie("tcgetwinsize()"); + } + + // Apply our options + if (width >= 0) { + ws.ws_col = width; + } + if (height >= 0) { + ws.ws_row = height; + } + if (xtcsetwinsize(pts, &ws) != 0) { + edie("tcsetwinsize()"); + } + + // Set custom terminal attributes + struct termios attrs; + if (tcgetattr(pts, &attrs) != 0) { + edie("tcgetattr()"); + } + attrs.c_oflag &= ~OPOST; // Don't convert \n to \r\n + if (tcsetattr(pts, TCSANOW, &attrs) != 0) { + edie("tcsetattr()"); + } + + pid_t pid = fork(); + if (pid < 0) { + edie("fork()"); + } else if (pid == 0) { + // Child + close(ptm); + + // Make ourselves a session leader so we can have our own + // controlling terminal + if (setsid() < 0) { + edie("setsid()"); + } + +#ifdef TIOCSCTTY + // Set the pty as the controlling terminal + if (ioctl(pts, TIOCSCTTY, 0) != 0) { + edie("ioctl(TIOCSCTTY)"); + } +#endif + + // Redirect std{in,out,err} to the pty + if (dup2(pts, STDIN_FILENO) < 0 + || dup2(pts, STDOUT_FILENO) < 0 + || dup2(pts, STDERR_FILENO) < 0) { + edie("dup2()"); + } + if (pts > STDERR_FILENO) { + xclose(pts); + } + + // Run the requested command + execvp(args[0], args); + edie("execvp(): %s", args[0]); + } + + // Parent + xclose(pts); + + // Read output from the pty and copy it to stdout + char buf[1024]; + while (true) { + ssize_t len = read(ptm, buf, sizeof(buf)); + if (len > 0) { + if (xwrite(STDOUT_FILENO, buf, len) < 0) { + edie("write()"); + } + } else if (len == 0) { + break; + } else if (errno == EINTR) { + continue; + } else if (errno == EIO) { + // Linux reports EIO rather than EOF when pts is closed + break; + } else { + die("read()"); + } + } + + xclose(ptm); + + int wstatus; + if (xwaitpid(pid, &wstatus, 0) < 0) { + edie("waitpid()"); + } + + if (WIFEXITED(wstatus)) { + return WEXITSTATUS(wstatus); + } else if (WIFSIGNALED(wstatus)) { + int sig = WTERMSIG(wstatus); + fprintf(stderr, "%s: %s: %s\n", cmd, args[0], strsignal(sig)); + return 128 + sig; + } else { + return 128; + } +} |