On 17/09/2021 19:25, Pádraig Brady wrote:
On 17/09/2021 18:43, Eric Blake wrote:
[IOn Wed, Sep 15, 2021 at 01:40:33PM +0100, Pádraig Brady wrote:
This format is a better default, since it results in simpler usage,
as you don't need to specify --tag on generation or -a on
checking invocations. Also it's a more general format supporting
mixed and length adjusted digests.
@@ -4143,6 +4153,8 @@ indicating there was a failure.
@item --tag
@opindex --tag
@cindex BSD output
+Note this option is not supported by the @command{cksum} command,
+as this is the default output format that it uses.
Shouldn't we still support the option, even if it is a no-op in the
common case, so that someone can do actions similar to:
alias mysum='cksum --untagged '
and then invoke 'mysum --tag' to turn it back on?
Maybe.
Perhaps on some systems only cksum might be installed,
with md5sum etc. being provided as simple wrappers like:
exec cksum -a md5 --untagged "$@"
Though that begs the question, should cksum support all of
--tag, --text, --binary ?
I'd be 60:40 for adding the --tag option to cksum,
I'll pushed the attached later to support cksum --tag
for the reasons above.
cheers,
Pádraig
>From 079cb6f87ee80a90b1723f662d41da426017a983 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A1draig=20Brady?= <p...@draigbrady.com>
Date: Mon, 20 Sep 2021 11:54:08 +0100
Subject: [PATCH] cksum: support more transparent emulation of older utils
* src/digest.c: Allow using the --untagged option with --check,
so that `cksum -a md5 --untagged` used to emulate md5sum for example,
may be augmented with the --check option. Also support the --tag
option with cksum, to allow overriding a previous --untagged setting.
* doc/coreutils.texi: Adjust accordingly.
* tests/misc/cksum-a.sh: Likewise.
---
doc/coreutils.texi | 8 ++++----
src/digest.c | 17 ++++++-----------
tests/misc/cksum-a.sh | 1 -
3 files changed, 10 insertions(+), 16 deletions(-)
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 05c5d2e5d..d962d363e 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -3934,8 +3934,9 @@ for each given @var{file}, or standard input if none are given or for a
@var{file} of @samp{-}.
cksum also supports the @option{-a,--algorithm} option to select the
-digest algorithm to use, and this is the preferred interface
-to these digests, subsuming the other standalone checksumming utilities.
+digest algorithm to use. @command{cksum} is the preferred interface
+to these digests, subsuming the other standalone checksumming utilities,
+which can be emulated using @code{cksum -a md5 --untagged "$@@"} etc.
Synopsis:
@example
@@ -4162,8 +4163,6 @@ indicating there was a failure.
@item --tag
@opindex --tag
@cindex BSD output
-Note this option is not supported by the @command{cksum} command,
-as this is the default output format that it uses.
Output BSD style checksums, which indicate the checksum algorithm used.
As a GNU extension, if @option{--zero} is not used, file names with problematic
characters are escaped as described above, with the same escaping indicator of
@@ -4171,6 +4170,7 @@ characters are escaped as described above, with the same escaping indicator of
The @option{--tag} option implies binary mode, and is disallowed with
@option{--text} mode as supporting that would unnecessarily complicate
the output format, while providing little benefit.
+The @command{cksum} command, uses @option{--tag} as its default output format.
@item -t
@itemx --text
diff --git a/src/digest.c b/src/digest.c
index 9398a133e..de2decc19 100644
--- a/src/digest.c
+++ b/src/digest.c
@@ -372,6 +372,7 @@ static struct option const long_options[] =
{ "status", no_argument, NULL, STATUS_OPTION },
{ "warn", no_argument, NULL, 'w' },
{ "strict", no_argument, NULL, STRICT_OPTION },
+ { "tag", no_argument, NULL, TAG_OPTION },
{ "zero", no_argument, NULL, 'z' },
# if HASH_ALGO_CKSUM
@@ -381,7 +382,6 @@ static struct option const long_options[] =
# else
{ "binary", no_argument, NULL, 'b' },
{ "text", no_argument, NULL, 't' },
- { "tag", no_argument, NULL, TAG_OPTION },
# endif
#else
@@ -452,6 +452,9 @@ Print or check %s (%d-bit) checksums.\n\
"), stdout);
# endif
# if HASH_ALGO_CKSUM
+ fputs (_("\
+ --tag create a BSD-style checksum (the default)\n\
+"), stdout);
fputs (_("\
--untagged create a reversed style checksum, without digest type\n\
"), stdout);
@@ -1335,12 +1338,11 @@ main (int argc, char **argv)
case UNTAG_OPTION:
prefix_tag = false;
break;
-# else
+# endif
case TAG_OPTION:
prefix_tag = true;
binary = 1;
break;
-# endif
case 'z':
digest_delim = '\0';
break;
@@ -1421,14 +1423,7 @@ main (int argc, char **argv)
"verifying checksums"));
usage (EXIT_FAILURE);
}
-#if HASH_ALGO_CKSUM
- if (!prefix_tag && do_check)
- {
- error (0, 0, _("the --untagged option is meaningless when "
- "verifying checksums"));
- usage (EXIT_FAILURE);
- }
-#else
+#if !HASH_ALGO_CKSUM
if (prefix_tag && do_check)
{
error (0, 0, _("the --tag option is meaningless when "
diff --git a/tests/misc/cksum-a.sh b/tests/misc/cksum-a.sh
index 9a58e1c2d..83dde1ff3 100755
--- a/tests/misc/cksum-a.sh
+++ b/tests/misc/cksum-a.sh
@@ -47,7 +47,6 @@ while read algo prog; do
done < input_options
compare out out-a || fail=1
-returns_ 1 cksum -a bsd --tag </dev/null || fail=1
returns_ 1 cksum -a bsd --check </dev/null || fail=1
Exit $fail
--
2.26.2
