script: new applet by Pascal Bellard <pascal.bellard AT ads-lu.com>

1 files changed, 195 insertions, 0 deletions

diff --git a/util-linux/script.c b/util-linux/script.c
new file mode 100644
index 000000000..fda726ed9
--- /dev/null
+++ b/util-linux/script.c
@@ -0,0 +1,195 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * script implementation for busybox
+ *
+ * pascal.bellard@ads-lu.com
+ *
+ * Based on code from util-linux v 2.12r
+ * Copyright (c) 1980
+ *      The Regents of the University of California.  All rights reserved.
+ *
+ * Licensed under GPLv2 or later, see file License in this tarball for details.
+ */
+
+#include "libbb.h"
+
+struct globals {
+        int child_pid;
+        int attr_ok; /* NB: 0: ok */
+        struct termios tt;
+        const char *fname;
+};
+#define G (*ptr_to_globals)
+#define child_pid (G.child_pid)
+#define attr_ok   (G.attr_ok  )
+#define tt        (G.tt       )
+#define fname     (G.fname    )
+#define INIT_G() do { \
+        PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
+        fname = "typescript"; \
+} while (0)
+
+static void done(void)
+{
+        if (child_pid) { /* we are parent */
+                if (attr_ok == 0)
+                        tcsetattr(0, TCSAFLUSH, &tt);
+                if (!(option_mask32 & 8)) /* not -q */
+                        printf("Script done, file is %s\n", fname);
+        }
+        exit(0);
+}
+
+#ifdef UNUSED
+static void handle_sigchld(int sig)
+{
+        /* wait for the exited child and exit */
+        while (wait_any_nohang(&sig) > 0)
+                continue;
+        done();
+}
+#endif
+
+#if ENABLE_GETOPT_LONG
+static const char getopt_longopts[] ALIGN1 =
+        "append\0"  No_argument       "a"
+        "command\0" Required_argument "c"
+        "flush\0"   No_argument       "f"
+        "quiet\0"   No_argument       "q"
+        ;
+#endif
+
+int script_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
+int script_main(int argc, char *argv[])
+{
+        int opt, pty;
+        int winsz_ok;
+        int mode;
+        struct termios rtt;
+        struct winsize win;
+        char line[32];
+        const char *shell;
+        char shell_opt[] = "-i";
+        char *shell_arg = NULL;
+
+        INIT_G();
+#if ENABLE_GETOPT_LONG
+        applet_long_options = getopt_longopts;
+#endif
+        opt_complementary = "?1"; /* max one arg */
+        opt = getopt32(argv, "ac:fq", &shell_arg);
+        //argc -= optind;
+        argv += optind;
+        if (argv[0]) {
+                fname = argv[0];
+        }
+        mode = O_CREAT|O_TRUNC|O_WRONLY;
+        if (opt & 1) {
+                mode = O_CREAT|O_APPEND|O_WRONLY;
+        }
+        if (opt & 2) {
+                shell_opt[1] = 'c';
+        }
+        if (!(opt & 8)) { /* not -q */
+                printf("Script started, file is %s\n", fname);
+        }
+        shell = getenv("SHELL");
+        if (shell == NULL) {
+                shell = _PATH_BSHELL;
+        }
+
+        pty = getpty(line, sizeof(line));
+        if (pty < 0) {
+                bb_perror_msg_and_die("can't get pty");
+        }
+
+        /* get current stdin's tty params */
+        attr_ok = tcgetattr(0, &tt);
+        winsz_ok = ioctl(0, TIOCGWINSZ, (char *)&win);
+
+        rtt = tt;
+        cfmakeraw(&rtt);
+        rtt.c_lflag &= ~ECHO;
+        tcsetattr(0, TCSAFLUSH, &rtt);
+
+        /* We exit as soon as child exits */
+        //signal(SIGCHLD, handle_sigchld);
+        signal(SIGCHLD, (void (*)(int)) done);
+
+        child_pid = vfork();
+        if (child_pid < 0) {
+                bb_perror_msg_and_die("vfork");
+        }
+
+        if (child_pid) {
+                /* parent */
+                char buf[256];
+                struct pollfd pfd[2];
+                int outfd;
+                int fd_count = 2;
+                struct pollfd *ppfd = pfd;
+
+                outfd = xopen(fname, mode);
+                pfd[0].fd = 0;
+                pfd[0].events = POLLIN;
+                pfd[1].fd = pty;
+                pfd[1].events = POLLIN;
+                ndelay_on(pty); /* this descriptor is not shared, can do this */
+                /* ndelay_on(0); - NO, stdin can be shared! */
+
+                /* copy stdin to pty master input,
+                 * copy pty master output to stdout and file */
+                /* TODO: don't use full_write's, use proper write buffering */
+                while (fd_count && safe_poll(ppfd, fd_count, -1) > 0) {
+                        if (pfd[0].revents) {
+                                int count = safe_read(0, buf, sizeof(buf));
+                                if (count <= 0) {
+                                        /* err/eof: don't read anymore */
+                                        pfd[0].revents = 0;
+                                        ppfd++;
+                                        fd_count--;
+                                } else {
+                                        full_write(pty, buf, count);
+                                }
+                        }
+                        if (pfd[1].revents) {
+                                int count;
+                                errno = 0;
+                                count = safe_read(pty, buf, sizeof(buf));
+                                if (count <= 0 && errno != EAGAIN) {
+                                        /* err/eof: don't read anymore */
+                                        pfd[1].revents = 0;
+                                        fd_count--;
+                                }
+                                if (count > 0) {
+                                        full_write(1, buf, count);
+                                        full_write(outfd, buf, count);
+                                        if (opt & 4) { /* -f */
+                                                fsync(outfd);
+                                        }
+                                }
+                        }
+                }
+                done(); /* does not return */
+        }
+
+        /* child: make pty slave to be input, output, error; run shell */
+        close(pty); /* close pty master */
+        /* open pty slave to fd 0,1,2 */
+        close(0);               
+        xopen(line, O_RDWR); /* uses fd 0 */
+        xdup2(0, 1);
+        xdup2(0, 2);
+        /* copy our original stdin tty's parameters to pty */
+        if (attr_ok == 0)
+                tcsetattr(0, TCSAFLUSH, &tt);
+        if (winsz_ok == 0)
+                ioctl(0, TIOCSWINSZ, (char *)&win);
+        /* set pty as a controlling tty */
+        setsid();
+        ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */);
+
+        /* signal(SIGCHLD, SIG_DFL); - exec does this for us */
+        execl(shell, shell, shell_opt, shell_arg, NULL);
+        bb_simple_perror_msg_and_die(shell);
+}