script: support non-option argument as command

[kzak@redhat.com: - don't use POSIXLY_CORRECT, use "+" in getopt_long(),
                  - use strv_join() rather than local concat function]

Based-on: https://github.com/util-linux/util-linux/pull/3599
Fixes: https://github.com/util-linux/util-linux/issues/3481
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/term-utils/script.1.adoc b/term-utils/script.1.adoc
index 894115c5bc8843cfc62a19e9a148eaf723812b40..688ec5e2dbc2f136677cdcc0b38e67f85d4cc7e1 100644 (file)
--- a/term-utils/script.1.adoc
+++ b/term-utils/script.1.adoc
@@ -49,7 +49,7 @@ script - make typescript of terminal session
 
 == SYNOPSIS
 
-*script* [options] [_file_]
+*script* [options] [_file_] [ -- program [arguments]]
 
 == DESCRIPTION
 
@@ -69,7 +69,7 @@ Below, the _size_ argument may be followed by the multiplicative suffixes KiB (=
 Append the output to _file_ or to _typescript_, retaining the prior contents.
 
 *-c*, *--command* _command_::
-Run the _command_ rather than an interactive shell. This makes it easy for a script to capture the output of a program that behaves differently when its stdout is not a tty.
+Run the _command_ rather than an interactive shell. This makes it easy for a script to capture the output of a program that behaves differently when its stdout is not a tty. It's possible to specify the command after '--' too.
 
 *-E*, *--echo* _when_::
 This option controls the *ECHO* flag for the slave end of the session's pseudoterminal. The supported modes are _always_, _never_, or _auto_.

diff --git a/term-utils/script.c b/term-utils/script.c
index 05e3fc8762a6663478353803ac84a52389ebcd51..80ea477ab4f355d23fa5bf63101d3f61a83b6af7 100644 (file)
--- a/term-utils/script.c
+++ b/term-utils/script.c
@@ -64,6 +64,7 @@
 #include "monotonic.h"
 #include "timeutils.h"
 #include "strutils.h"
+#include "strv.h"
 #include "xalloc.h"
 #include "optutils.h"
 #include "signames.h"
@@ -190,7 +191,7 @@ static void __attribute__((__noreturn__)) usage(void)
 {
        FILE *out = stdout;
        fputs(USAGE_HEADER, out);
-       fprintf(out, _(" %s [options] [file]\n"), program_invocation_short_name);
+       fprintf(out, _(" %s [options] [file] [-- program [arguments]]\n"), program_invocation_short_name);
 
        fputs(USAGE_SEPARATOR, out);
        fputs(_("Make a typescript of a terminal session.\n"), out);
@@ -207,7 +208,8 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(USAGE_SEPARATOR, out);
 
        fputs(_(" -a, --append                  append to the log file\n"), out);
-       fputs(_(" -c, --command <command>       run command rather than interactive shell\n"), out);
+       fputs(_(" -c, --command <command>       run command rather than interactive shell\n"
+               "                                 (alternative to '-- program [arguments]')\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);
@@ -813,7 +815,7 @@ int main(int argc, char **argv)
 
        ctl.isterm = isatty(STDIN_FILENO);
 
-       while ((ch = getopt_long(argc, argv, "aB:c:eE:fI:O:o:qm:T:t::Vh", longopts, NULL)) != -1) {
+       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);
 
@@ -888,12 +890,25 @@ int main(int argc, char **argv)
                        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 (argc > 0) {
+               /* if argv[0] is not after --, use argv[0] as outfile */
+               if (argc > 0 && strcmp(argv[-1], "--") != 0) {
                        outfile = argv[0];
                        argc--;
                        argv++;
@@ -906,9 +921,29 @@ int main(int argc, char **argv)
                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 '-- program' are mutually exclusive"));
+                       errtryhelp(EXIT_FAILURE);
+               }
+
+               ctl.command = strv_join(argv, " ");
+               if (!ctl.command)
+                       errx(EXIT_FAILURE, _("failed to concatenate arguments"));
+
+               ctl.command_norm = xstrdup(ctl.command);
+               strrep(ctl.command_norm, '\n', ' ');
+               argc = 0;
+       }
+
        if (argc > 0) {
-               /* only one filename is accepted. if --log-out was given,
-                * freestanding filename is ignored */
                warnx(_("unexpected number of arguments"));
                errtryhelp(EXIT_FAILURE);
        }