[thirdparty/util-linux.git] / term-utils / script.c

/*
 * Copyright (C) 1980      Regents of the University of California.
 * Copyright (C) 2013-2019 Karel Zak <kzak@redhat.com>
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include <stdio.h>
#include <stdlib.h>
#include <paths.h>
#include <time.h>
#include <sys/stat.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <signal.h>
#include <errno.h>
#include <string.h>
#include <getopt.h>
#include <unistd.h>
#include <fcntl.h>
#include <limits.h>
#include <locale.h>
#include <stddef.h>
#include <sys/wait.h>
#include <poll.h>
#include <sys/signalfd.h>
#include <assert.h>
#include <inttypes.h>

#include "closestream.h"
#include "nls.h"
#include "c.h"
#include "cctype.h"
#include "ttyutils.h"
#include "all-io.h"
#include "monotonic.h"
#include "timeutils.h"
#include "strutils.h"
#include "strv.h"
#include "xalloc.h"
#include "optutils.h"
#include "signames.h"
#include "pty-session.h"
#include "debug.h"

static UL_DEBUG_DEFINE_MASK(script);
UL_DEBUG_DEFINE_MASKNAMES(script) = UL_DEBUG_EMPTY_MASKNAMES;

#define SCRIPT_DEBUG_INIT       (1 << 1)
#define SCRIPT_DEBUG_PTY        (1 << 2)
#define SCRIPT_DEBUG_IO         (1 << 3)
#define SCRIPT_DEBUG_SIGNAL     (1 << 4)
#define SCRIPT_DEBUG_MISC       (1 << 5)
#define SCRIPT_DEBUG_ALL        0xFFFF

#define DBG(m, x)       __UL_DBG(script, SCRIPT_DEBUG_, m, x)
#define ON_DBG(m, x)    __UL_DBG_CALL(script, SCRIPT_DEBUG_, m, x)

#ifdef HAVE_LIBUTEMPTER
# include <utempter.h>
#endif

#define DEFAULT_TYPESCRIPT_FILENAME "typescript"

/*
 * Script is driven by stream (stdout/stdin) activity. It's possible to
 * associate arbitrary number of log files with the stream. We have two basic
 * types of log files: "timing file" (simple or multistream) and "data file"
 * (raw).
 *
 * The same log file maybe be shared between both streams. For example
 * multi-stream timing file is possible to use for stdin as well as for stdout.
 */
enum {
        SCRIPT_FMT_RAW = 1,             /* raw slave/master data */
        SCRIPT_FMT_TIMING_SIMPLE,       /* (classic) in format "<delta> <offset>" */
        SCRIPT_FMT_TIMING_MULTI,        /* (advanced) multiple streams in format "<type> <delta> <offset|etc> */
};

struct script_log {
        FILE    *fp;                    /* file pointer (handler) */
        int     format;                 /* SCRIPT_FMT_* */
        char    *filename;              /* on command line specified name */
        struct timeval oldtime;         /* previous entry log time (SCRIPT_FMT_TIMING_* only) */
        struct timeval starttime;

        unsigned int    initialized : 1;
};

struct script_stream {
        struct script_log **logs;       /* logs where to write data from stream */
        size_t nlogs;                   /* number of logs */
        char ident;                     /* stream identifier */
};

struct script_control {
        uint64_t outsz;         /* current output files size */
        uint64_t maxsz;         /* maximum output files size */

        struct script_stream    out;    /* output */
        struct script_stream    in;     /* input */

        struct script_log       *siglog;        /* log for signal entries */
        struct script_log       *infolog;       /* log for info entries */

        const char *ttyname;
        const char *ttytype;
        const char *command;
        char *command_norm;     /* normalized (without \n) */
        int ttycols;
        int ttylines;

        struct ul_pty *pty;     /* pseudo-terminal */
        pid_t child;            /* child pid */
        int childstatus;        /* child process exit value */

        bool    append,         /* append output */
                rc_wanted,      /* return child exit value */
                flush,          /* flush after each write */
                quiet,          /* suppress most output */
                force,          /* write output to links */
                isterm;         /* is child process running as terminal */
};

static ssize_t log_info(struct script_control *ctl, const char *name, const char *msgfmt, ...)
                        __attribute__((__format__ (__printf__, 3, 4)));

static void script_init_debug(void)
{
        __UL_INIT_DEBUG_FROM_ENV(script, SCRIPT_DEBUG_, 0, SCRIPT_DEBUG);
}

static void init_terminal_info(struct script_control *ctl)
{
        if (ctl->ttyname || !ctl->isterm)
                return;         /* already initialized */

        get_terminal_dimension(&ctl->ttycols, &ctl->ttylines);
        get_terminal_name(&ctl->ttyname, NULL, NULL);
        get_terminal_type(&ctl->ttytype);
}

/*
 * For tests we want to be able to control time output
 */
#ifdef TEST_SCRIPT
static inline time_t script_time(time_t *t)
{
        const char *str = getenv("SCRIPT_TEST_SECOND_SINCE_EPOCH");
        int64_t sec;

        if (!str || sscanf(str, "%"SCNi64, &sec) != 1)
                return time(t);
        if (t)
                *t = (time_t)sec;
        return (time_t)sec;
}
#else   /* !TEST_SCRIPT */
# define script_time(x) time(x)
#endif

static void __attribute__((__noreturn__)) usage(void)
{
        FILE *out = stdout;
        fputs(USAGE_HEADER, out);
        fprintf(out, _(" %s [options] [<file>] [-- <command> [<argument>...]]\n"), program_invocation_short_name);

        fputs(USAGE_SEPARATOR, out);
        fputs(_("Make a typescript of a terminal session.\n"), out);

        fputs(USAGE_OPTIONS, out);
        fputs(_(" -I, --log-in <file>           log stdin to file\n"), out);
        fputs(_(" -O, --log-out <file>          log stdout to file (default)\n"), out);
        fputs(_(" -B, --log-io <file>           log stdin and stdout to file\n"), out);
        fputs(USAGE_SEPARATOR, out);

        fputs(_(" -T, --log-timing <file>       log timing information to file\n"), out);
        fputs(_(" -t[<file>], --timing[=<file>] deprecated alias to -T (default file is stderr)\n"), out);
        fputs(_(" -m, --logging-format <name>   force to 'classic' or 'advanced' format\n"), out);
        fputs(USAGE_SEPARATOR, out);

        fputs(_(" -a, --append                  append to the log file\n"), out);
        fputs(_(" -c, --command <command>       run <command> rather than an interactive shell\n"
                "                                 (alternative to '-- <command> [<argument...>]')\n"), out);
        fputs(_(" -e, --return                  return exit code of the child process\n"), out);
        fputs(_(" -f, --flush                   run flush after each write\n"), out);
        fputs(_("     --force                   use output file even when it is a link\n"), out);
        fputs(_(" -E, --echo <when>             echo input in session (auto, always or never)\n"), out);
        fputs(_(" -o, --output-limit <size>     terminate if output files exceed size\n"), out);
        fputs(_(" -q, --quiet                   be quiet\n"), out);

        fputs(USAGE_SEPARATOR, out);
        fprintf(out, USAGE_HELP_OPTIONS(31));

        fputs(USAGE_ARGUMENTS, out);
        fprintf(out, USAGE_ARG_SIZE(_("<size>")));

        fprintf(out, USAGE_MAN_TAIL("script(1)"));

        exit(EXIT_SUCCESS);
}

static struct script_log *get_log_by_name(struct script_stream *stream,
                                          const char *name)
{
        size_t i;

        for (i = 0; i < stream->nlogs; i++) {
                struct script_log *log = stream->logs[i];
                if (strcmp(log->filename, name) == 0)
                        return log;
        }
        return NULL;
}

static struct script_log *log_associate(struct script_control *ctl,
                                        struct script_stream *stream,
                                        const char *filename, int format)
{
        struct script_log *log;

        DBG(MISC, ul_debug("associate %s with stream", filename));

        assert(ctl);
        assert(filename);
        assert(stream);

        log = get_log_by_name(stream, filename);
        if (log)
                return log;     /* already defined */

        log = get_log_by_name(stream == &ctl->out ? &ctl->in : &ctl->out, filename);
        if (!log) {
                /* create a new log */
                log = xcalloc(1, sizeof(*log));
                log->filename = xstrdup(filename);
                log->format = format;
        }

        /* add log to the stream */
        stream->logs = xreallocarray(stream->logs,
                        stream->nlogs + 1, sizeof(log));
        stream->logs[stream->nlogs] = log;
        stream->nlogs++;

        /* remember where to write info about signals */
        if (format == SCRIPT_FMT_TIMING_MULTI) {
                if (!ctl->siglog)
                        ctl->siglog = log;
                if (!ctl->infolog)
                        ctl->infolog = log;
        }

        return log;
}

static int log_close(struct script_control *ctl,
                      struct script_log *log,
                      const char *msg,
                      int status)
{
        int rc = 0;

        if (!log || !log->initialized)
                return 0;

        DBG(MISC, ul_debug("closing %s", log->filename));

        switch (log->format) {
        case SCRIPT_FMT_RAW:
        {
                char buf[FORMAT_TIMESTAMP_MAX];
                time_t tvec = script_time((time_t *)NULL);

                strtime_iso(&tvec, ISO_TIMESTAMP, buf, sizeof(buf));
                if (msg)
                        fprintf(log->fp, _("\nScript done on %s [<%s>]\n"), buf, msg);
                else
                        fprintf(log->fp, _("\nScript done on %s [COMMAND_EXIT_CODE=\"%d\"]\n"), buf, status);
                break;
        }
        case SCRIPT_FMT_TIMING_MULTI:
        {
                struct timeval now = { 0 }, delta = { 0 };

                gettime_monotonic(&now);
                timersub(&now, &log->starttime, &delta);

                log_info(ctl, "DURATION", "%"PRId64".%06"PRId64,
                        (int64_t)delta.tv_sec,
                        (int64_t)delta.tv_usec);
                log_info(ctl, "EXIT_CODE", "%d", status);
                break;
        }
        case SCRIPT_FMT_TIMING_SIMPLE:
                break;
        }

        if (close_stream(log->fp) != 0) {
                warn(_("write failed: %s"), log->filename);
                rc = -errno;
        }

        free(log->filename);
        memset(log, 0, sizeof(*log));

        return rc;
}

static int log_flush(struct script_control *ctl __attribute__((__unused__)), struct script_log *log)
{

        if (!log || !log->initialized)
                return 0;

        DBG(MISC, ul_debug("flushing %s", log->filename));

        fflush(log->fp);
        return 0;
}

static void log_free(struct script_control *ctl, struct script_log *log)
{
        size_t i;

        if (!log)
                return;

        /* the same log is possible to reference from more places, remove all
         * (TODO: maybe use include/list.h to make it more elegant)
         */
        if (ctl->siglog == log)
                ctl->siglog = NULL;
        else if (ctl->infolog == log)
                ctl->infolog = NULL;

        for (i = 0; i < ctl->out.nlogs; i++) {
                if (ctl->out.logs[i] == log)
                        ctl->out.logs[i] = NULL;
        }
        for (i = 0; i < ctl->in.nlogs; i++) {
                if (ctl->in.logs[i] == log)
                        ctl->in.logs[i] = NULL;
        }
        free(log);
}

static int log_start(struct script_control *ctl,
                      struct script_log *log)
{
        if (log->initialized)
                return 0;

        DBG(MISC, ul_debug("opening %s", log->filename));

        assert(log->fp == NULL);

        /* open the log */
        log->fp = fopen(log->filename,
                        ctl->append && log->format == SCRIPT_FMT_RAW ?
                        "a" UL_CLOEXECSTR :
                        "w" UL_CLOEXECSTR);
        if (!log->fp) {
                warn(_("cannot open %s"), log->filename);
                return -errno;
        }

        /* write header, etc. */
        switch (log->format) {
        case SCRIPT_FMT_RAW:
        {
                int x = 0;
                char buf[FORMAT_TIMESTAMP_MAX];
                time_t tvec = script_time((time_t *)NULL);

                strtime_iso(&tvec, ISO_TIMESTAMP, buf, sizeof(buf));
                fprintf(log->fp, _("Script started on %s ["), buf);

                if (ctl->command)
                        x += fprintf(log->fp, "COMMAND=\"%s\"", ctl->command_norm);

                if (ctl->isterm) {
                        init_terminal_info(ctl);

                        if (ctl->ttytype)
                                x += fprintf(log->fp, "%*sTERM=\"%s\"", !!x, "", ctl->ttytype);
                        if (ctl->ttyname)
                                x += fprintf(log->fp, "%*sTTY=\"%s\"", !!x, "", ctl->ttyname);

                        x += fprintf(log->fp, "%*sCOLUMNS=\"%d\" LINES=\"%d\"", !!x, "",
                                        ctl->ttycols, ctl->ttylines);
                } else
                        fprintf(log->fp, _("%*s<not executed on terminal>"), !!x, "");

                fputs("]\n", log->fp);
                break;
        }
        case SCRIPT_FMT_TIMING_SIMPLE:
        case SCRIPT_FMT_TIMING_MULTI:
                gettime_monotonic(&log->oldtime);
                gettime_monotonic(&log->starttime);
                break;
        }

        log->initialized = 1;
        return 0;
}

static int logging_start(struct script_control *ctl)
{
        size_t i;

        /* start all output logs */
        for (i = 0; i < ctl->out.nlogs; i++) {
                int rc = log_start(ctl, ctl->out.logs[i]);
                if (rc)
                        return rc;
        }

        /* start all input logs */
        for (i = 0; i < ctl->in.nlogs; i++) {
                int rc = log_start(ctl, ctl->in.logs[i]);
                if (rc)
                        return rc;
        }
        return 0;
}

static ssize_t log_write(struct script_control *ctl,
                      struct script_stream *stream,
                      struct script_log *log,
                      char *obuf, size_t bytes)
{
        int rc;
        ssize_t ssz = 0;
        struct timeval now, delta;

        if (!log->fp)
                return 0;

        DBG(IO, ul_debug(" writing [file=%s]", log->filename));

        switch (log->format) {
        case SCRIPT_FMT_RAW:
                DBG(IO, ul_debug("  log raw data"));
                rc = fwrite_all(obuf, 1, bytes, log->fp);
                if (rc) {
                        warn(_("cannot write %s"), log->filename);
                        return rc;
                }
                ssz = bytes;
                break;

        case SCRIPT_FMT_TIMING_SIMPLE:
                DBG(IO, ul_debug("  log timing info"));

                gettime_monotonic(&now);
                timersub(&now, &log->oldtime, &delta);
                ssz = fprintf(log->fp, "%"PRId64".%06"PRId64" %zd\n",
                        (int64_t)delta.tv_sec, (int64_t)delta.tv_usec, bytes);
                if (ssz < 0)
                        return -errno;

                log->oldtime = now;
                break;

        case SCRIPT_FMT_TIMING_MULTI:
                DBG(IO, ul_debug("  log multi-stream timing info"));

                gettime_monotonic(&now);
                timersub(&now, &log->oldtime, &delta);
                ssz = fprintf(log->fp, "%c %"PRId64".%06"PRId64" %zd\n",
                        stream->ident,
                        (int64_t)delta.tv_sec, (int64_t)delta.tv_usec, bytes);
                if (ssz < 0)
                        return -errno;

                log->oldtime = now;
                break;
        default:
                break;
        }

        if (ctl->flush)
                fflush(log->fp);
        return ssz;
}

static ssize_t log_stream_activity(
                        struct script_control *ctl,
                        struct script_stream *stream,
                        char *buf, size_t bytes)
{
        size_t i;
        ssize_t outsz = 0;

        for (i = 0; i < stream->nlogs; i++) {
                ssize_t ssz = log_write(ctl, stream, stream->logs[i], buf, bytes);

                if (ssz < 0)
                        return ssz;
                outsz += ssz;
        }

        return outsz;
}

static ssize_t __attribute__ ((__format__ (__printf__, 3, 4)))
        log_signal(struct script_control *ctl, int signum, const char *msgfmt, ...)
{
        struct script_log *log;
        struct timeval now, delta;
        char msg[BUFSIZ] = {0};
        va_list ap;
        ssize_t sz;

        assert(ctl);

        log = ctl->siglog;
        if (!log)
                return 0;

        assert(log->format == SCRIPT_FMT_TIMING_MULTI);
        DBG(IO, ul_debug("  writing signal to multi-stream timing"));

        gettime_monotonic(&now);
        timersub(&now, &log->oldtime, &delta);

        if (msgfmt) {
                int rc;
                va_start(ap, msgfmt);
                rc = vsnprintf(msg, sizeof(msg), msgfmt, ap);
                va_end(ap);
                if (rc < 0)
                        *msg = '\0';;
        }

        if (*msg)
                sz = fprintf(log->fp, "S %"PRId64".%06"PRId64" SIG%s %s\n",
                        (int64_t)delta.tv_sec, (int64_t)delta.tv_usec,
                        signum_to_signame(signum), msg);
        else
                sz = fprintf(log->fp, "S %"PRId64".%06"PRId64" SIG%s\n",
                        (int64_t)delta.tv_sec, (int64_t)delta.tv_usec,
                        signum_to_signame(signum));

        log->oldtime = now;
        return sz;
}

static ssize_t log_info(struct script_control *ctl, const char *name, const char *msgfmt, ...)
{
        struct script_log *log;
        char msg[BUFSIZ] = {0};
        va_list ap;
        ssize_t sz;

        assert(ctl);

        log = ctl->infolog;
        if (!log)
                return 0;

        assert(log->format == SCRIPT_FMT_TIMING_MULTI);
        DBG(IO, ul_debug("  writing info to multi-stream log"));

        if (msgfmt) {
                int rc;
                va_start(ap, msgfmt);
                rc = vsnprintf(msg, sizeof(msg), msgfmt, ap);
                va_end(ap);
                if (rc < 0)
                        *msg = '\0';;
        }

        if (*msg)
                sz = fprintf(log->fp, "H %f %s %s\n", 0.0, name, msg);
        else
                sz = fprintf(log->fp, "H %f %s\n", 0.0, name);

        return sz;
}


static void logging_done(struct script_control *ctl, const char *msg)
{
        int status;
        size_t i;

        DBG(MISC, ul_debug("stop logging"));

        if (WIFSIGNALED(ctl->childstatus))
                status = WTERMSIG(ctl->childstatus) + 0x80;
        else
                status = WEXITSTATUS(ctl->childstatus);

        DBG(MISC, ul_debug(" status=%d", status));

        /* close all output logs */
        for (i = 0; i < ctl->out.nlogs; i++) {
                struct script_log *log = ctl->out.logs[i];
                log_close(ctl, log, msg, status);
                log_free(ctl, log);
        }
        free(ctl->out.logs);
        ctl->out.logs = NULL;
        ctl->out.nlogs = 0;

        /* close all input logs */
        for (i = 0; i < ctl->in.nlogs; i++) {
                struct script_log *log = ctl->in.logs[i];
                log_close(ctl, log, msg, status);
                log_free(ctl, log);
        }
        free(ctl->in.logs);
        ctl->in.logs = NULL;
        ctl->in.nlogs = 0;
}

static void callback_child_die(
                        void *data,
                        pid_t child __attribute__((__unused__)),
                        int status)
{
        struct script_control *ctl = (struct script_control *) data;

        ctl->child = (pid_t) -1;
        ctl->childstatus = status;
}

static void callback_child_sigstop(
                        void *data __attribute__((__unused__)),
                        pid_t child)
{
        DBG(SIGNAL, ul_debug(" child stop by SIGSTOP -- stop parent too"));
        kill(getpid(), SIGSTOP);
        DBG(SIGNAL, ul_debug(" resume"));
        kill(child, SIGCONT);
}

static int callback_log_stream_activity(void *data, int fd, char *buf, size_t bufsz)
{
        struct script_control *ctl = (struct script_control *) data;
        ssize_t ssz = 0;

        DBG(IO, ul_debug("stream activity callback"));

        /* from stdin (user) to command */
        if (fd == STDIN_FILENO)
                ssz = log_stream_activity(ctl, &ctl->in, buf, (size_t) bufsz);

        /* from command (master) to stdout and log */
        else if (fd == ul_pty_get_childfd(ctl->pty))
                ssz = log_stream_activity(ctl, &ctl->out, buf, (size_t) bufsz);

        if (ssz < 0)
                return (int) ssz;

        DBG(IO, ul_debug(" append %zd bytes [summary=%" PRIu64 ", max=%" PRIu64 "]", ssz,
                                ctl->outsz, ctl->maxsz));

        ctl->outsz += ssz;

        /* check output limit */
        if (ctl->maxsz != 0 && ctl->outsz >= ctl->maxsz) {
                if (!ctl->quiet)
                        printf(_("Script terminated, max output files size %"PRIu64" exceeded.\n"), ctl->maxsz);
                DBG(IO, ul_debug("output size %"PRIu64", exceeded limit %"PRIu64, ctl->outsz, ctl->maxsz));
                logging_done(ctl, _("max output size exceeded"));
                return 1;
        }
        return 0;
}

static int callback_log_signal(void *data, struct signalfd_siginfo *info, void *sigdata)
{
        struct script_control *ctl = (struct script_control *) data;
        ssize_t ssz = 0;

        switch (info->ssi_signo) {
        case SIGWINCH:
        {
                struct winsize *win = (struct winsize *) sigdata;
                ssz = log_signal(ctl, info->ssi_signo, "ROWS=%d COLS=%d",
                                        win->ws_row, win->ws_col);
                break;
        }
        case SIGTERM:
                FALLTHROUGH;
        case SIGINT:
                FALLTHROUGH;
        case SIGQUIT:
                ssz = log_signal(ctl, info->ssi_signo, NULL);
                break;
        default:
                /* no log */
                break;
        }

        return ssz < 0 ? ssz : 0;
}

static int callback_flush_logs(void *data)
{
        struct script_control *ctl = (struct script_control *) data;
        size_t i;

        for (i = 0; i < ctl->out.nlogs; i++) {
                int rc = log_flush(ctl, ctl->out.logs[i]);
                if (rc)
                        return rc;
        }

        for (i = 0; i < ctl->in.nlogs; i++) {
                int rc = log_flush(ctl, ctl->in.logs[i]);
                if (rc)
                        return rc;
        }
        return 0;
}

static void die_if_link(struct script_control *ctl, const char *filename)
{
        struct stat s;

        if (ctl->force)
                return;
        if (lstat(filename, &s) == 0 && (S_ISLNK(s.st_mode) || s.st_nlink > 1))
                errx(EXIT_FAILURE,
                     _("output file `%s' is a link\n"
                       "Use --force if you really want to use it.\n"
                       "Program not started."), filename);
}

int main(int argc, char **argv)
{
        struct script_control ctl = {
                .out = { .ident = 'O' },
                .in  = { .ident = 'I' },
        };
        struct ul_pty_callbacks *cb;
        int ch, format = 0, caught_signal = 0, rc = 0, echo = 1;
        const char *outfile = NULL, *infile = NULL;
        const char *timingfile = NULL, *shell = NULL;

        enum { FORCE_OPTION = CHAR_MAX + 1 };

        static const struct option longopts[] = {
                {"append", no_argument, NULL, 'a'},
                {"command", required_argument, NULL, 'c'},
                {"echo", required_argument, NULL, 'E'},
                {"return", no_argument, NULL, 'e'},
                {"flush", no_argument, NULL, 'f'},
                {"force", no_argument, NULL, FORCE_OPTION,},
                {"log-in", required_argument, NULL, 'I'},
                {"log-out", required_argument, NULL, 'O'},
                {"log-io", required_argument, NULL, 'B'},
                {"log-timing", required_argument, NULL, 'T'},
                {"logging-format", required_argument, NULL, 'm'},
                {"output-limit", required_argument, NULL, 'o'},
                {"quiet", no_argument, NULL, 'q'},
                {"timing", optional_argument, NULL, 't'},
                {"version", no_argument, NULL, 'V'},
                {"help", no_argument, NULL, 'h'},
                {NULL, 0, NULL, 0}
        };
        static const ul_excl_t excl[] = {       /* rows and cols in ASCII order */
                { 'T', 't' },
                { 0 }
        };
        int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
        setlocale(LC_ALL, "");
        /*
         * script -t prints time delays as floating point numbers.  The example
         * program (scriptreplay) that we provide to handle this timing output
         * is a perl script, and does not handle numbers in locale format (not
         * even when "use locale;" is added).  So, since these numbers are not
         * for human consumption, it seems easiest to set LC_NUMERIC here.
         */
        setlocale(LC_NUMERIC, "C");
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
        close_stdout_atexit();

        script_init_debug();
        ON_DBG(PTY, ul_pty_init_debug(0xFFFF));

        ctl.isterm = isatty(STDIN_FILENO);

        while ((ch = getopt_long(argc, argv, "+aB:c:eE:fI:O:o:qm:T:t::Vh", longopts, NULL)) != -1) {

                err_exclusive_options(ch, longopts, excl, excl_st);

                switch (ch) {
                case 'a':
                        ctl.append = 1;
                        break;
                case 'c':
                        ctl.command = optarg;
                        ctl.command_norm = xstrdup(ctl.command);
                        ul_strrep(ctl.command_norm, '\n', ' ');
                        break;
                case 'E':
                        if (strcmp(optarg, "auto") == 0)
                                ; /* keep default */
                        else if (strcmp(optarg, "never") == 0)
                                echo = 0;
                        else if (strcmp(optarg, "always") == 0)
                                echo = 1;
                        else
                                errx(EXIT_FAILURE, _("unsupported echo mode: '%s'"), optarg);
                        break;
                case 'e':
                        ctl.rc_wanted = 1;
                        break;
                case 'f':
                        ctl.flush = 1;
                        break;
                case FORCE_OPTION:
                        ctl.force = 1;
                        break;
                case 'B':
                        log_associate(&ctl, &ctl.in, optarg, SCRIPT_FMT_RAW);
                        log_associate(&ctl, &ctl.out, optarg, SCRIPT_FMT_RAW);
                        infile = outfile = optarg;
                        break;
                case 'I':
                        log_associate(&ctl, &ctl.in, optarg, SCRIPT_FMT_RAW);
                        infile = optarg;
                        break;
                case 'O':
                        log_associate(&ctl, &ctl.out, optarg, SCRIPT_FMT_RAW);
                        outfile = optarg;
                        break;
                case 'o':
                        ctl.maxsz = strtosize_or_err(optarg, _("failed to parse output limit size"));
                        break;
                case 'q':
                        ctl.quiet = 1;
                        break;
                case 'm':
                        if (c_strcasecmp(optarg, "classic") == 0)
                                format = SCRIPT_FMT_TIMING_SIMPLE;
                        else if (c_strcasecmp(optarg, "advanced") == 0)
                                format = SCRIPT_FMT_TIMING_MULTI;
                        else
                                errx(EXIT_FAILURE, _("unsupported logging format: '%s'"), optarg);
                        break;
                case 't':
                        if (optarg && *optarg == '=')
                                optarg++;
                        timingfile = optarg ? optarg : "/dev/stderr";
                        break;
                case 'T' :
                        timingfile = optarg;
                        break;
                case 'V':
                        print_version(EXIT_SUCCESS);
                case 'h':
                        usage();
                default:
                        errtryhelp(EXIT_FAILURE);
                }
        }

        argc -= optind;
        argv += optind;

        /*
         * Note that "--" separates non-option arguments. The script can be
         * used with an <outfile> name as well as with a <command>. The
         * <outfile> is always before "--" and <command> is always after "--".
         * Possible combinations are:
         *
         * script [options] <outfile>
         * script [options] -- <command ...>
         * script [options] <outfile> -- <command ...>
         */

        /* default if no --log-* specified */
        if (!outfile && !infile) {
                /* if argv[0] is not after --, use argv[0] as outfile */
                if (argc > 0 && strcmp(argv[-1], "--") != 0) {
                        outfile = argv[0];
                        argc--;
                        argv++;
                } else {
                        die_if_link(&ctl, DEFAULT_TYPESCRIPT_FILENAME);
                        outfile = DEFAULT_TYPESCRIPT_FILENAME;
                }

                /* associate stdout with typescript file */
                log_associate(&ctl, &ctl.out, outfile, SCRIPT_FMT_RAW);
        }

        /* skip -- to non-option arguments */
        if (argc > 0 && strcmp(argv[0], "--") == 0) {
                argc--;
                argv++;
        }

        /* concat non-option arguments as command */
        if (argc > 0 && strcmp(argv[-1], "--") == 0) {
                if (ctl.command != NULL) {
                        warnx(_("option --command and a command after '--' cannot be combined"));
                        errtryhelp(EXIT_FAILURE);
                }

                ctl.command = ul_strv_join(argv, " ");
                if (!ctl.command)
                        errx(EXIT_FAILURE, _("failed to concatenate arguments"));

                ctl.command_norm = xstrdup(ctl.command);
                ul_strrep(ctl.command_norm, '\n', ' ');
                argc = 0;
        }

        if (argc > 0) {
                warnx(_("unexpected number of arguments"));
                errtryhelp(EXIT_FAILURE);
        }

        if (timingfile) {
                /* the old SCRIPT_FMT_TIMING_SIMPLE should be used when
                 * recoding output only (just for backward compatibility),
                 * otherwise switch to new format. */
                if (!format)
                        format = infile || (outfile && infile) ?
                                        SCRIPT_FMT_TIMING_MULTI :
                                        SCRIPT_FMT_TIMING_SIMPLE;

                else if (format == SCRIPT_FMT_TIMING_SIMPLE && outfile && infile)
                        errx(EXIT_FAILURE, _("log multiple streams is mutually "
                                             "exclusive with 'classic' format"));
                if (outfile)
                        log_associate(&ctl, &ctl.out, timingfile, format);
                if (infile)
                        log_associate(&ctl, &ctl.in, timingfile, format);
        }

        shell = getenv("SHELL");
        if (!shell)
                shell = _PATH_BSHELL;

        ctl.pty = ul_new_pty(ctl.isterm);
        if (!ctl.pty)
                err(EXIT_FAILURE, "failed to allocate PTY handler");

        ul_pty_slave_echo(ctl.pty, echo);

        ul_pty_set_callback_data(ctl.pty, (void *) &ctl);
        cb = ul_pty_get_callbacks(ctl.pty);
        cb->child_die = callback_child_die;
        cb->child_sigstop = callback_child_sigstop;
        cb->log_stream_activity = callback_log_stream_activity;
        cb->log_signal = callback_log_signal;
        cb->flush_logs = callback_flush_logs;

        if (!ctl.quiet) {
                printf(_("Script started"));
                if (outfile)
                        printf(_(", output log file is '%s'"), outfile);
                if (infile)
                        printf(_(", input log file is '%s'"), infile);
                if (timingfile)
                        printf(_(", timing file is '%s'"), timingfile);
                printf(_(".\n"));
        }


        if (ul_pty_setup(ctl.pty))
                err(EXIT_FAILURE, _("failed to create pseudo-terminal"));

#ifdef HAVE_LIBUTEMPTER
        utempter_add_record(ul_pty_get_childfd(ctl.pty), NULL);
#endif

        if (ul_pty_signals_setup(ctl.pty))
                err(EXIT_FAILURE, _("failed to initialize signals handler"));
        fflush(stdout);

        /*
         * We have terminal, do not use err() from now, use "goto done"
         */

        switch ((int) (ctl.child = fork())) {
        case -1: /* error */
                warn(_("cannot create child process"));
                rc = -errno;
                goto done;

        case 0: /* child */
        {
                const char *shname;

                ul_pty_init_slave(ctl.pty);

                signal(SIGTERM, SIG_DFL); /* because /etc/csh.login */

                shname = strrchr(shell, '/');
                shname = shname ? shname + 1 : shell;

                if (access(shell, X_OK) == 0) {
                        if (ctl.command)
                                execl(shell, shname, "-c", ctl.command, (char *)NULL);
                        else
                                execl(shell, shname, "-i", (char *)NULL);
                } else {
                        if (ctl.command)
                                execlp(shname, shname, "-c", ctl.command, (char *)NULL);
                        else
                                execlp(shname, shname, "-i", (char *)NULL);
                }

                err(EXIT_FAILURE, "failed to execute %s", shell);
                break;
        }
        default:
                break;
        }

        /* parent */
        ul_pty_set_child(ctl.pty, ctl.child);

        rc = logging_start(&ctl);
        if (rc)
                goto done;

        /* add extra info to advanced timing file */
        if (timingfile && format == SCRIPT_FMT_TIMING_MULTI) {
                char buf[FORMAT_TIMESTAMP_MAX];
                time_t tvec = script_time((time_t *)NULL);

                strtime_iso(&tvec, ISO_TIMESTAMP, buf, sizeof(buf));
                log_info(&ctl, "START_TIME", "%s", buf);

                if (ctl.isterm) {
                        init_terminal_info(&ctl);
                        log_info(&ctl, "TERM", "%s", ctl.ttytype);
                        log_info(&ctl, "TTY", "%s", ctl.ttyname);
                        log_info(&ctl, "COLUMNS", "%d", ctl.ttycols);
                        log_info(&ctl, "LINES", "%d", ctl.ttylines);
                }
                log_info(&ctl, "SHELL", "%s", shell);
                if (ctl.command)
                        log_info(&ctl, "COMMAND", "%s", ctl.command_norm);
                log_info(&ctl, "TIMING_LOG", "%s", timingfile);
                if (outfile)
                        log_info(&ctl, "OUTPUT_LOG", "%s", outfile);
                if (infile)
                        log_info(&ctl, "INPUT_LOG", "%s", infile);
        }

        /* this is the main loop */
        rc = ul_pty_proxy_master(ctl.pty);

        /* all done; cleanup and kill */
        caught_signal = ul_pty_get_delivered_signal(ctl.pty);

        if (!caught_signal && ctl.child != (pid_t)-1)
                ul_pty_wait_for_child(ctl.pty); /* final wait */

        if (caught_signal && ctl.child != (pid_t)-1) {
                fprintf(stderr, "\nSession terminated, killing shell...");
                kill(ctl.child, SIGTERM);
                sleep(2);
                kill(ctl.child, SIGKILL);
                fprintf(stderr, " ...killed.\n");
        }

done:
        ul_pty_cleanup(ctl.pty);
        logging_done(&ctl, NULL);

        if (!ctl.quiet)
                printf(_("Script done.\n"));

#ifdef HAVE_LIBUTEMPTER
        if (ul_pty_get_childfd(ctl.pty) >= 0)
                utempter_remove_record(ul_pty_get_childfd(ctl.pty));
#endif
        ul_free_pty(ctl.pty);

        /* default exit code */
        rc = rc ? EXIT_FAILURE : EXIT_SUCCESS;

        /* exit code based on child status */
        if (ctl.rc_wanted && rc == EXIT_SUCCESS) {
                if (WIFSIGNALED(ctl.childstatus))
                        rc = WTERMSIG(ctl.childstatus) + 0x80;
                else
                        rc = WEXITSTATUS(ctl.childstatus);
        }

        DBG(MISC, ul_debug("done [rc=%d]", rc));
        return rc;
}