* doc/coreutils.texi (stat invocation): Add a paragraph documenting
stat's output format when the --terse option is specified, both in
normal and in --file-system mode.
Reported by Dan Jacobson <jidanni@jidanni.org>
in http://bugs.gnu.org/18624
* src/dd.c: Report the transfer progress every second when the
new status=progress level is used. Adjust the handling and
description of the status= option so that they're treated as
mutually exclusive levels, rather than flags with implicit precedence.
* doc/coreutils.texi (dd invocation): Document the new progress
status level. Reference the new level in the description of SIGUSR1.
* tests/dd/stats.sh: Add new test for status=progress.
* tests/dd/misc.sh: Change so status=none only takes precedence
if it's the last level specified.
* NEWS: Mention the feature.
* src/dd.c (ifd_reopen): A new wrapper to ensure we
don't exit upon receiving a SIGUSR1 in a blocking open()
on a fifo for example.
(iftruncate): Likewise for ftruncate().
(iread): Process signals also after a short read.
(install_signal_handlers): Install SIGINFO/SIGUSR1 handler
even if set to SIG_IGN, as this is what the parent can easily
set from a shell script that can send SIGUSR1 without the
possiblity of inadvertently killing the dd process.
* doc/coreutils.texi (dd invocation): Improve the example to
show robust usage wrt signal races and short reads.
* tests/dd/stats.sh: A new test for various signal races.
* tests/local.mk: Reference the new test.
* NEWS: Mention the fix.
* src/system.h (emit_ancillary_info): For commands that don't have
a 1:1 mapping with the texinfo node names, provide a mapping to
the correct node.
* doc/coreutils.texi: Add some extra cross references noticed while
checking this.
Fixes http://bugs.debian.org/762092
This supports longstanding shell commands like
'info coreutils "touch invocation"'.
Problem reported by Vincent Lefevre via Bob Proulx in:
http://bugs.gnu.org/18428
* doc/coreutils.texi (Multi-call invocation):
Rename from "coreutils invocation".
* doc/coreutils.texi (df invocation): Add a sentence that eliding
duplicate entries for the same file system is not limited to bind
mounts, but also happens for remote file systems like NFS.
Since commit v8.22-94-g99960ee, chroot(1) skips the chroot(2) syscall
for "/" arguments (and synonyms). The problem is that it also skips
the following chdir("/") call in that case. The latter breaks existing
scripts which expect "/" to be the working directory inside the chroot.
While the first part of the change - i.e., skipping chroot("/") - is
okay for consistency with systems where it might succeed for a non-root
user, the second part might be malicious, e.g.
cd /home/user && chroot '/' bin/foo
In the "best" case, chroot(1) could not execute 'bin/foo' with ENOENT,
but in the worst case, chroot(1) would execute '/home/user/bin/foo' in
the case that exists - instead of '/bin/foo'.
Revert that second part of the patch, i.e., perform the chdir("/)
in the common case again - unless the new --skip-chdir option is
specified. Restrict this new option to the case of "/" arguments.
* src/chroot.c (SKIP_CHDIR): Add enum.
(long_opts): Add entry for the new --skip-chdir option.
(usage): Add --skip-chdir option, and while at it, move the other
to options into alphabetical order.
(main): Accept the above new option, allowing it only in the case
when NEWROOT is the old "/".
Move down the chdir() call after the if-clause to ensure it is
run in any case - unless --skip-chdir is specified.
Add a 'newroot' variable for the new root directory as it is used
in a couple of places now.
* tests/misc/chroot-fail.sh: Invert the last tests which check the
working directory of the execvp()ed program when a "/"-like
argument was passed: now expect it to be "/" - unless --skip-chdir
is given.
* doc/coreutils.texi (chroot invocation): Document the new option.
Document that chroot(1) usually calls chdir("/") unless the new
--skip-chdir option is specified. Sort options.
* NEWS (Changes in behavior): Mention the fix.
(New features): Mention the new option.
* init.cfg (nonroot_has_perm_): Add chroot's new --skip-chdir option.
* tests/cp/preserve-gid.sh (t1): Likewise.
* tests/cp/special-bits.sh: Likewise.
* tests/id/setgid.sh: Likewise.
* tests/misc/truncate-owned-by-other.sh: Likewise.
* tests/mv/sticky-to-xpart.sh: Likewise.
* tests/rm/fail-2eperm.sh: Likewise.
* tests/rm/no-give-up.sh: Likewise.
* tests/touch/now-owned-by-other.sh: Likewise.
Reported by Andreas Schwab in http://bugs.gnu.org/18062
Add the --enable-single-binary option to the configure file.
When enabled, this option builds a single binary file containing
the selected tools. Which tool gets executed depends on the value
of argv[0] which can be set implicitly through symlinks to the
single program.
This setup reduces significantly the size of a complete coreutils
install, since code from lib/libcoreutils.a is not duplicated in
every one of the more than 100 binaries. Runtime overhead is
increased due to more dynamic libraries being loaded, and extra
initialization being performed for all utils. Also initially
a larger binary is loaded from storage, though this is usually
alleviated due to caching and lazy mmaping of unused blocks,
and in fact the single binary should have better caching
characteristics.
Comparing the size of the individual versus single binary on x86_64:
$ cd src
$ size coreutils
$ size -t $(../build-aux/gen-lists-of-programs.sh --list-progs |
grep -Ev '(coreutils|libstdbuf)') | tail -n1
text data bss dec hex filename
1097416 5388 88432 1191236 122d44 src/coreutils
4901010 124964 163768 5189742 4f306e (TOTALS)
Storage requirements are reduced similarly:
$ cd src
$ du -h coreutils
$ du -ch $(../build-aux/gen-lists-of-programs.sh --list-progs |
grep -Ev '(coreutils|libstdbuf)') | tail -n1
1.2M coreutils
5.3M total
When installing, the makefile will create either symlinks or
shebangs based on the --enable-single-binary setting, for
each configured tool. In this way, all the tools are still
callable individually, but they are all implemented by the same
"coreutils" binary installed on the same directory.
* .gitignore: Add new generated files.
* Makefile.am: New rules to generate build-aux/gen-single-binary.sh
and install symlinks.
* NEWS: Mention the new feature.
* README: Add "coreutils" to the list of utils.
* bootstrap.conf: Regenerate src/single-binary.mk
* build-aux/gen-lists-of-programs.sh: New --list-progs option.
* build-aux/gen-single-binary.sh: Regenerate
* configure.ac: New --enable-single-binary option and other variables.
Disallow --enable-single-binary=symlinks with --program-prefix et. al.
* man/coreutils.x: Manpage hook.
* man/local.mk: Add manpage hook and fix dependencies.
* src/coreutils.c: Multicall implementation.
* src/local.mk: New rules for the single binary option.
* tests/local.mk: Add $single_binary_progs to support
require_built_() from init.cfg
* tests/misc/env.sh: Avoid the use of symlink to echo.
* tests/misc/help-version.sh: Add exception for coreutils.
* tests/install/basic-1.sh: Really avoid using ginstall strip
functionality if there is an issue with the independent strip command.
* src/kill.c: Changes to call exit() in main.
* src/readlink.c: Likewise.
* src/shuf.c: Likewise.
* src/timeout.c: Likewise.
* src/truncate.c: Likewise.
Revert commit v8.22-131-g3e89d5b as even though POSIX
states that the default mode should be -L,
common practice for stand-alone pwd implementations
is to default to -P.
* src/pwd.c (usage): Retain mention of the default mode of operation.
Suggested by Bob Proulx
* src/pwd.c (main): Adjust default mode to be "logical"
and independent of the POSIXLY_CORRECT env var.
(usage): Mention the default mode of operation.
* doc/coreutils.texi (pwd invocation): Adjust accordingly.
* tests/misc/pwd-option.sh: Likewise.
* NEWS: Mention the change in behavior.
* doc/coreutils.texi (chown invocation): Mention the system dependent
restrictions on setting groups.
(chgrp invocation): Likewise. Reference the 'chown' superset.
* man/chgrp.x: Cross reference chown(1) which is the superset interface,
and also chown(2) which gives details of the platform restrictions.
Fixes http://bugs.gnu.org/17495
* src/install.c (install_file_in_file_parents): Factor out the
creation of any parent directories into ...
(mkancesdirs_safe_wd): ... this new function.
(install_file_in_dir): Add the parameter 'mkdir_and_install', and
call the above new function if it evaluates to true.
(main): During parsing of the -t option, move the check whether
the target_directory exists down after the option parsing loop,
and do not complain about stat(optarg,...) failing if -D was given.
Pass 'mkdir_and_install' to install_file_in_dir().
* doc/coreutils.texi (install invocation): Remove the (false)
restriction that -D would be ignored together with -t. Instead,
clarify install's new bahavior.
Fix the node's reference in the top-level @direntry for consistency.
* src/install/basic-1.sh: Add tests for the now-allowed combination
of the -D and -t options.
* NEWS: Mention the improvement.
* src/join.c (usage): Reword to avoid implication that
the NUL byte is only generated as the output delimeter.
* src/sort.c (usage): Likewise.
* src/shuf.c (usage): Likewise. Also since we're changing the
translation string take the opportunity to separate out
the description to a separate string to reduce translation overhead.
* src/uniq.c (usage): Likewise.
* src/stty.c (usage): s/null/NUL/ for consistency.
* src/basename.c (usage): Reword for accuracy/consistency.
* src/dirname.c (usage): Likewise.
* src/du.c (usage): Likewise.
* src/env.c (usage): Likewise.
* src/printenv.c (usage): Likewise.
* src/readlink.c (usage): Likewise.
* src/realpath.c (usage): Likewise.
* doc/coreutils.texi: Consolidate/share the descriptions of
--null, --zero and --zero-terminated.
It's dangerous and confusing to leave root's supplemental
groups in place when specifying other users with --userspec.
In the edge case that that is desired one can explicitly
specify --groups.
Also we implicitly set the system defined supplemental groups
for a user. The existing mechanism where supplemental groups
needed to be explicitly specified is confusing and not general
when the lookup needs to be done within the chroot.
Also we extend the --groups syntax slightly to allow clearing
the set of supplementary groups using --groups=''.
* src/chroot.c (setgroups): On systems without supplemental groups,
clearing then is a noop and so should return success.
(main): Lookup the primary GID with getpwuid() when just a numeric
uid is specified, and also infer the USERNAME from this call,
needed when we're later looking up the supplemental groups for a user.
Support clearing supplemental groups, either implicitly for
unknown users, or explicitly when --groups='' is specified.
* tests/misc/chroot-credentials.sh: Various new test cases
* doc/coreutils.texi (chroot invocation): Adjust for the new behavior.
* NEWS: Mention the change in behavior.
Problem reported by Don Baggett in <http:/bugs.gnu.org/17422>.
* NEWS:
* doc/coreutils.texi (dd invocation): Document this.
* src/dd.c (conversions): conv=ascii implies conv=unblock.
conv=ebcdic and conv=ibm imply conv=block.
(ascii_to_ebcdic, ebcdic_to_ascii): Correct to match
POSIX 1003.1-2013.
* tests/dd/ascii.sh: New file.
* tests/local.mk (all_tests): Add it.
* src/numfmt.c (setup_padding_buffer): Simplify the code by not
explicitly dealing with heap exhaustion.
(parse_format_string): Likewise. Handle multiple grouping
modifiers as does the standard printf. Handle the new leading
zero --format modifier.
(double_to_human): Use more defensive coding against overwriting
stack buffers. Honor the leading zeros width.
(usage): Mention the leading zero --format modifier.
(main): Allow --padding in combo with a --format (width),
as the number of leading zeros are useful independent of
the main field width.
* doc/coreutils.texi (numfmt invocation): Likewise.
* tests/misc/numfmt.pl: Add new test cases.
* NEWS: Mention the improvement.
* doc/coreutils.texi (pr invocation): Clarify that -w or -W
will be rounded down so that each column has the same width.
Adjust the wording for -W, to avoid the implication that the
width of -S is insignificant to the page width.
* src/pr.c (usage): Add a period to avoid ambiguity in
the man page output.
* doc/coreutils.texi (shred invocation): Mention some reasons
why clearing slack space might be useful.
* src/shred.c (do_wipefd): Add initial writes for each pass
for small regular files in case the storage for those is
in the inode, and thus a larger write up to a block size would
bypass that. Move the direct I/O control to...
(dopass): ... here so we can avoid enabling it for these small
initial writes. It's better to retry direct I/O for each pass
anyway to handle the case where direct I/O is disabled for only
the last portion of a file when the size is not a multiple of
the block size. Note we don't avoid the sync for the initial
write as it will be small but more importantly could be on a
different part of the disk and so worth doing independently
to ensure the write is not discarded.
* tests/misc/shred-exact.sh: Check some more direct I/O cases.
* NEWS: Mention the improvements.
The inode storage issue was mentioned by Paul Eggert.
The description of -u was inaccurate when combined with -D:
$ printf '%s\n' '1 a' '2 a' | uniq -uD -f1
1 a
* doc/coreutils.texi (uniq invocation): Clarify that it's
the last repeated line that is suppressed from the output.
Fixes http://bugs.gnu.org/17022
- Support arbitrary numbers in --groups, consistent with
what is already done for --userspec
- Avoid look-ups entirely for --groups items with a leading '+'
- Support names that are actually numbers in --groups
- Ignore an empty --groups="" option for consistency with --userspec
- Look up both inside and outside the chroot with inside taking
precedence. The look-up outside may load required libraries
to complete the look-up inside the chroot. This can happen for
example with a 32 bit chroot on a 64 bit system, where the
32 bit NSS plugins within the chroot fail to load.
* src/chroot.c (parse_additional_groups): A new function refactored
from set_addition_groups(), to just do the parsing. The actual
setgroups() call is separated out for calling from the chroot later.
(main): Call parse_user_spec() and parse_additional_groups()
both outside and inside the chroot for the reasons outlined above.
* tests/misc/chroot-credentials.sh: Ensure arbitrary numeric IDs
can be specified without causing look-up errors.
* NEWS: Mention the improvements.
* THANKS.in: Add Norihiro Kamae who initially reported the issue
with a proposed patch.
Also thanks to Dmitry V. Levin for his diagnosis and sample patch.
* doc/coreutils.texi (dd invocation): Add an example for how to call
dd to save data from a failing disk. Mention GNU 'ddrescue' as one
of the more specialized tools in such a case.
* src/od.c (main): Handle the new --endian option,
taking "little" and "big" as parameters.
(usage): Describe the new option.
(PRINT_FIELDS): Adjust to swap bytes if required.
* tests/misc/od-endian.sh: A new test to verify
the byte swapping operations for hex (ints) and floats
for all sizes between 1 and 16 inclusive.
* test/local.mk: Reference the new test.
* doc/coreutils.texi (od invocation): Describe the new option.
* NEWS: Mention the new feature.
* src/ls.c: Remove all mention of SELinux since ls
should treat all security context labels equally.
* doc/coreutils.texi (ls invocation): Likewise.
(id invocation): Clarify that -Z outputs the context
inherited by the process, rather than one specific to a user.
Note for SMACK this can be set instead by the SMACK64EXEC label,
in the unusual case where this is set on the id executable.
* src/id.c (usage): Likewise.
* src/mkdir.c (usage): Clarify that -Z is specific to SELinux,
while --context=CTX is also supported for SMACK.
* src/mkfifo.c (usage): Likewise.
* src/mknod.c (usage): Likewise.
Run "make update-copyright", but then also run this,
perl -pi -e 's/2\d\d\d-//' tests/sample-test
to make that one script use the single most recent year number.
Original problem reported by Philipp Thomas in
<http://bugs.gnu.org/16061>.
* NEWS: shuf --repeat, not shuf --repetitions.
* doc/coreutils.texi (shuf invocation):
* src/shuf.c (usage, long_opts, main):
* tests/misc/shuf.sh:
Likewise. Also, the default head-count is infinity.
Since v8.21-172-g33660b4, df not only treats symbolic link arguments
differently, as stated there, but now generally processes special file
arguments in a non-canonicalized form correctly:
$ cd /dev && df-old sdb
Filesystem 1K-blocks Used Available Use% Mounted on
devtmpfs 1014572 48 1014524 1% /dev
$ cd /dev && df-new sdb
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sdb 10190136 6039532 3609932 63% /home
Document df's new behavior.
* doc/coreutils.texi (df invocation): In the paragraph describing
df's behavior regarding special file arguments, relax the condition
for such special files from "... is an absolute name of ..." to
"... resolves to ...".
* NEWS (Bug fixes): Mention the new behavior also here.
* doc/coreutils.texi (ls invocation): Remove the note about
OSX terminals not aligning properly as this is no longer the case.
Tested by: Philipp Thomas
cp, mv, install, mkdir, mkfifo, mknod are adjusted so that:
-Z no longer accepts an argument.
-Z or --context without an argument do not warn without SELinux.
--context with an argument will warn without SELinux.
* src/local.mk: Reference the new selinux module where required.
* src/system.h: Make the argument to --context optional.
* src/mkdir.c: Likewise. Also handle the SMACK case for --context.
Note we currently silently ignore -Z with SMACK.
* src/mkfifo.c: Likewise.
* src/mknod.c: Likewise.
* src/install.c: Likewise. Note install(1) by default already
set the context for target files to their system default,
albeit with an older method. Use the -Z option to select between
the old and new context restoration behavior, and document
the differences and details for how context restoration
is done in new and old methods, with a view disabling the
old method entirely in future.
* src/cp.c: Make the argument to --context optional.
Note -Z implies --no-preserve=context. I.E. -Z overrides
that aspect of -a no matter what order specified.
(struct cp_options): Document the context handling options.
(main): Check/adjust option combinations after all
options are processed, to both simplify processing
and to make handling independent of order of options
on the command line. Also improve the diagnostics
from a failed call to setfscreatecon().
(set_process_security_ctx): A new function,
refactored to set the default context from the source file,
or with the type adjusted as per the system default for
the destination path.
(set_file_security_ctx): A new function refactored to
set the security context of an existing file, either based on
the process context or the default system context for a path.
(copy_internal): Use the refactored functions to simplify
error handling and consistently fail or warn as needed.
(copy_reg): Likewise.
(copy_internal): With --preserve=context, also copy
context from non regular files. Note for directories this may
impact the copying of subsequent files to that directory?
(copy_attr): If we're handling SELinux explicitly,
then exclude to avoid the redudant copy with --preserve=context,
and the problematic copy with -Z. Note SELinux attribute exclusion
also now honors cp -a --no-preserve=context. Note there was a
very small window over 10 years ago, where attr_copy_file was
available, while attr_copy_check_permissions was not, so we
don't bother adding an explicit m4 check for the latter function.
* src/mv.c: Support --context, but don't allow specifying an argument.
* src/chcon.c: Adjust a comment to be specific to SELinux.
* src/runcon.c: Likewise.
* src/copy.c: Honor the context settings to "restorecon" as appropriate.
* src/copy.h: Add a new setting to select "restorecon" functionality.
* tests/mkdir/selinux.sh: s/-Z/--context=/
* tests/cp/cp-a-selinux.sh: Augment this test with cases
testing basic -Z functionality, and also test the various
invalid option combinations and option precedence.
* tests/mkdir/restorecon.sh: Add a new test for the
more involved mkdir -Z handling, since the directory changing
and non existent directories need to be specially handled.
Also check the similar but simpler handling of -Z by mk{nod,fifo}.
* tests/local.mk: Reference the new test.
* doc/coreutils.texi (cp invocation): Update as per interface changes.
(mv invocation): Likewise.
(install invocation): Likewise.
(mkfifo invocation): Likewise.
(mknod invocation): Likewise.
(mkdir invocation): Likewise.
* NEWS: Mention the new feature and change in behavior.
A sync operation is very often expensive. For illustration
I timed the following python script which indicated that
each ext4 dir sync was taking about 2ms and 12ms, on an
SSD and traditional disk respectively.
import os
d=os.open(".", os.O_DIRECTORY|os.O_RDONLY)
for i in range(1000):
os.fdatasync(d)
So syncing for each character for each file can result
in significant delays. Often this overhead is redundant,
as only the data is sensitive and not the file name.
Even if the names are sensitive, your file system may
employ synchronous metadata updates, which also makes
explicit syncing redundant.
* tests/misc/shred-remove.sh: Ensure all the new parameters
actually unlink the file.
* doc/coreutils.texi (shred invocation): Describe the new
parameters to the --remove option.
* src/shred.c (Usage): Likewise.
(main): Parse the new options.
(wipename): Inspect the new enum to see which of
the now optional tasks to perform.
* NEWS: Mention the new feature.
* THANKS.in: Add reporter Joseph D. Wagner
* src/df.c (usage): Document the new 'file' --output field.
(get_dev): Add a new parameter to pass the specified
argument from the command line through. Use '-' if a
command line parameter is not being used.
* doc/coreutils.texi (df invocation): Describe the new 'file' field.
* tests/df/df-output.sh: Adjust all fields test, and
add a specific test for --output=file.
* NEWS: Mention the new feature.
* src/ls.c (usage): Mention -k only changes the display
for disk usage (directory total, and ls -s), and imply
that it can be overridden (by --block-size, and -h).
* doc/coreutils.texi (block size): Mention that ls -k
handling is different to other utilities.
Addresses http://bugs.gnu.org/14525
The error diagnostic
"rm: cannot remove directory: '.'"
does not give the user a hint for the reason.
Issue a clearer error message.
* src/remove.c (rm_fts): Enhance the error diagnostic in the above
case to emphasize that skipping is done deliberately.
In the corresponding comment, mention that POSIX mandates this
behavior. Likewise in the subsequent comment for skipping "/".
* doc/coreutils.texi (rm invocation): In the paragraph describing
the above behavior, mention that POSIX mandates it.
This adds support for using a constant or "stick" parity bit.
* src/stty.c (usage): Mention the new flag.
* tests/misc/stty.sh: Adjust for the new flag.
* NEWS: Mention the improvement.
* docs/coreutils.texi (stty invocation): Mention the new flag.
* src/copy.c (create_hard_link): Add a bool 'dereference' parameter,
and pass AT_SYMLINK_FOLLOW as 'flags' to linkat() when dereference
is true.
(should_dereference): Add new 'bool' function to determine if a
file should be dereferenced or not.
(copy_internal): Use the above new should_dereference() and remember
its return value in a new local bool 'dereference' variable. Use that
in all three calls to create_hard_link().
* src/cp.c (main): after parsing the options, if x.dereference is
still DEFEF_UNDEFINED and the x.recursive is true, then only set
x.dereference to DEREF_NEVER iff --link was not specified.
* doc/coreutils.texi (cp invocation): Mention that cp(1) does not
follow symbolic links in the source when --link is specified.
Likewise in the description of the -R option when used together with
that option.
* tests/cp/same-file.sh: Adapt the expected results for the -fl,
the -bl and the -bfl tests.
* tests/cp/link-deref.sh: Add a new test.
* tests/local.mk (all_tests): Reference the above new test.
* NEWS (Changes in behavior): Mention the change.
This fixes http://bugs.gnu.org/15173
Co-authored-by: Bernhard Voelker <mail@bernhard-voelker.de>
* doc/coreutils.texi (cp invocation): Give more detail about what's
happening in the example, explicitly calling out the --no-dereference
option required to make the -H and -L options significant.
Also mention the option order significance of the -H and -L options.
Fixes http://bugs.gnu.org/15579
* doc/coreutils.texi (paste invocation): Move the synopsis to the top.
Provide examples for the different type of operations possible.
Add a specific common example to join consecutive lines with a space.
* src/id.c (usage): Remove 'name' from the synopsis,
implying that one can also specify by user ID.
(main): Like chown(1), call parse_user_spec() to implement
user name or ID lookup with appropriate precedence.
* doc/coreutils.texi (id invocation): Mention that
a user ID is supported and how '+' affects lookup order.
* tests/misc/id-groups.sh: Remove test now subsumed into...
* tests/misc/id-uid.sh: New test covering new interface.
* tests/local.mk: Rename the test.
* NEWS: Mention the new feature.
Addresses http://bugs.gnu.org/15421
* src/group-list.h (print_group_list): Add a parameter for the
delimiter of type char.
* src/group-list.c (print_group_list): Likewise, and use it instead
of a white space character to delimit the group entries.
* src/groups.c (main): Pass white space character to print_group_list().
* src/id.c (longopts): Add array element for the new long option.
(usage): Document the new option. While at it, fix the alignment
of the descriptions to match that of HELP_OPTION_DESCRIPTION.
(main): Define the bool flag opt_zero indicating the use of the
new option. In the getopt_long loop, handle it.
Output an error diagnostic in the case the --zero option has been
specified together with the default format.
In the case of -gG, pass either a NUL or a white space character to
print_group_list() - depending on the above new flag.
Likewise change the printing of the final newline character: output
a NUL instead if the --zero option has been specified.
* doc/coreutils.texi (id invocation): Document the new option.
While at it, move the @exitstatus macro down after the macro
@primaryAndSupplementaryGroups in order to be consistent with
other texinfo documents.
(groups invocation): Move @exitstatus down after the macro
@primaryAndSupplementaryGroups here, too.
* tests/misc/id-zero.sh: Add new test exercising the new option.
* tests/local.mk (all_tests): Reference it.
* NEWS (New features): Mention the new option.
Fixes http://bugs.gnu.org/9987
* doc/coreutils.texi (seq invocation): Add a sentence clarifying
that seq terminates when LAST becomes smaller than the current number
plus INCREMENT.
* src/seq.c (usage): Likewise.
Fixes http://bugs.gnu.org/15068
