Paul Eggert said:
> Given that hardly anybody uses pr any more, I'm surprised that the
> Austin Group still cares about its options. It's an obsolete utility,
> and ought to be deprecated.
True, but this option seems simple enough to implement.
How about the attached patch?
Collin
>From 5b4ac990e8dd43d8f3e1371e2e78271c9b35345e Mon Sep 17 00:00:00 2001
Message-ID: <5b4ac990e8dd43d8f3e1371e2e78271c9b35345e.1753655792.git.collin.fu...@gmail.com>
From: Collin Funk <collin.fu...@gmail.com>
Date: Sun, 27 Jul 2025 15:00:15 -0700
Subject: [PATCH] pr: implement '-p' as required by POSIX Issue 6
* src/pr.c (pause_option): New variable.
(short_options): Add '-p'.
(long_options): Add '--pause'.
(main): Add the option. Only allow its use when stdout is a tty.
(print_files): If the option is use emit '\a' to stderr and wait until a
newline is read to print the next page.
(usage): Mention the new option.
* doc/coreutils.texi (pr invocation): Document the new option.
---
doc/coreutils.texi | 8 ++++++++
src/pr.c | 30 ++++++++++++++++++++++++++----
2 files changed, 34 insertions(+), 4 deletions(-)
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 7ca5b222c..14b98ea01 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -2825,6 +2825,14 @@ @node pr invocation
set with the @option{-W/-w} option. A limited overflow may occur with
numbered single column output (compare @option{-n} option).
+@item -p
+@itemx --pause
+@opindex -p
+@opindex --pause
+After printing each page, print an alert (bell) to standard error and
+wait for a newline to be read from standard input before printing the
+next page.
+
@item -r
@itemx --no-file-warnings
@opindex -r
diff --git a/src/pr.c b/src/pr.c
index e7081a059..5ccc7bf8a 100644
--- a/src/pr.c
+++ b/src/pr.c
@@ -711,6 +711,9 @@ static char *custom_header;
/* (-D) Date format for the header. */
static char const *date_format;
+/* If true, pause after each page until a newline is read from stdin. */
+static bool pause_option;
+
/* The local time zone rules, as per the TZ environment variable. */
static timezone_t localtz;
@@ -738,7 +741,7 @@ enum
};
static char const short_options[] =
- "-0123456789D:FJN:S::TW:abcde::fh:i::l:mn::o:rs::tvw:";
+ "-0123456789D:FJN:S::TW:abcde::fh:i::l:mn::po:rs::tvw:";
static struct option const long_options[] =
{
@@ -758,6 +761,7 @@ static struct option const long_options[] =
{"number-lines", optional_argument, nullptr, 'n'},
{"first-line-number", required_argument, nullptr, 'N'},
{"indent", required_argument, nullptr, 'o'},
+ {"pause", no_argument, nullptr, 'p'},
{"no-file-warnings", no_argument, nullptr, 'r'},
{"separator", optional_argument, nullptr, 's'},
{"sep-string", optional_argument, nullptr, 'S'},
@@ -999,6 +1003,9 @@ main (int argc, char **argv)
chars_per_margin = getoptnum (optarg, 0,
_("'-o MARGIN' invalid line offset"));
break;
+ case 'p':
+ pause_option = true;
+ break;
case 'r':
ignore_failed_opens = true;
break;
@@ -1079,6 +1086,10 @@ main (int argc, char **argv)
error (EXIT_FAILURE, 0,
_("cannot specify both printing across and printing in parallel"));
+ if (pause_option && ! isatty (STDOUT_FILENO))
+ error (EXIT_FAILURE, 0,
+ _("cannot use --pause (-p) unless writing and reading from a tty"));
+
/* Translate some old short options to new/long options.
To meet downward compatibility with other UNIX pr utilities
and some POSIX specifications. */
@@ -1147,7 +1158,7 @@ main (int argc, char **argv)
cleanup ();
- if (have_read_stdin && fclose (stdin) == EOF)
+ if ((have_read_stdin || pause_option) && fclose (stdin) == EOF)
error (EXIT_FAILURE, errno, _("standard input"));
main_exit (failed_opens ? EXIT_FAILURE : EXIT_SUCCESS);
}
@@ -1636,8 +1647,17 @@ print_files (int number_of_files, char **av)
init_funcs ();
line_number = line_count;
- while (print_page ())
- ;
+ for (;;)
+ {
+ if (pause_option)
+ {
+ putc ('\a', stderr);
+ while (getchar () != '\n')
+ ;
+ }
+ if (! print_page ())
+ break;
+ }
}
/* Initialize header information.
@@ -2824,6 +2844,8 @@ Paginate or columnate FILE(s) for printing.\n\
-o, --indent=MARGIN\n\
offset each line with MARGIN (zero) spaces, do not\n\
affect -w or -W, MARGIN will be added to PAGE_WIDTH\n\
+ -p, --pause pause at the beginning of each page until a newline\n\
+ is read from standard input.\n\
-r, --no-file-warnings\n\
omit warning when a file cannot be opened\n\
"), stdout);
--
2.50.1
