The function read_buffer() implements read and clear functionally, but
we do not differentiate between these actions in main() for error
messages, and one generic "dmesg: read kernel buffer failed" is used
in all cases. That's a bug.
This patch removes the "clear" action from read_buffer() and keeps it
for buffer reading only. The "clear" action is implemented in main()
by separate klogctl(SYSLOG_ACTION_CLEAR) for cases. It means also for
"dmesg --read-clear"; we do not use SYSLOG_ACTION_READ_CLEAR anymore.
Now "clear+read" is:
* syslog: SYSLOG_ACTION_READ_ALL + SYSLOG_ACTION_CLEAR
* kmsg: /dev/kmsg read() + SYSLOG_ACTION_CLEAR
In old versions "dmesg --syslog --read-clear" (syalog backed) was
implemented by logctl(SYSLOG_ACTION_READ_CLEAR) and it returns no
data for non-root users (due to EPERM), "dmesg --read-clear" (kmsg)
returns data and EPERM for the "clear" action.
Now the command "dmesg --syslog --read-clear" and "dmesg --read-clear"
behaves in the same way -- returns data and EPERM for the "clear"
action.
Fixes: https://github.com/karelzak/util-linux/issues/1255
Signed-off-by: Karel Zak <kzak@redhat.com>
Timestamps in kernel log comes from monotonic clocksource which does not
tick when system suspended. Suspended time easily sums into hours and days
rendering human readable timestamps in dmesg useless.
Adjusting timestamps accouring to current delta between boottime and
monotonic clocksources produces accurate timestamps for messages printed
since last resume. Which are supposed to be most interesting.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Option --follow-new (-W) works the same as --follow (-w) but initially
seeks to the end of kernel ring buffer, so it prints only new messages.
Useful for capturing kernel messages during actions without past log.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
... but I have doubts this change fixes the issue. It seems (on my
system) that \0 is already filtered out by kernel/syslog.
Addresses: https://github.com/karelzak/util-linux/issues/862
Signed-off-by: Karel Zak <kzak@redhat.com>
We have no way how to print the kernel message buffer in really raw
way. The new option --noescape disables all \x<hex> translations.
Addresses: https://github.com/karelzak/util-linux/issues/858
Signed-off-by: Karel Zak <kzak@redhat.com>
These strings are expected to be wrote exactly as they are parsed, so make
translating them impossible. Since mkfs.cramfs -N option arguments need
this treatment use opportunity to slice usage() output to multiple lines.
Addresses: https://bugs.debian.org/907568
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
The current code ignores single-byte non-printable characters.
Reported-by: Marc Deslauriers <marc.deslauriers@canonical.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
sys-utils/dmesg.c: In function ‘print_record.constprop.12’:
sys-utils/dmesg.c:1039:14: warning: ‘mesg_size’ may be used uninitialized in this function [-Wuninitialized]
Signed-off-by: Karel Zak <kzak@redhat.com>
* Start the ISO format flags at bit 0 instead of bit 1.
* Remove unnecessary _8601 from ISO format flag names to
avoid line wrapping and to ease readability.
* ISO timestamps have date-time-timzone in common, so move
the TIMEZONE flag to bit 2 causing all timestamp masks
to have the first three bits set and the last four bits
as timestamp 'options'.
* Change the 'SPACE' flag to a 'T' flag, because it makes
the code and comments more concise.
* Add common ISO timestamp masks.
* Implement the ISO timestamp masks in all applicable code
using the strxxx_iso() functions.
Signed-off-by: J William Piggott <elseifthen@gmx.com>
The kernel outputs multi-line messages (kernel messages that contain
the end-of-line character '\n'). These message are currently displayed by
dmesg as
[965199.028940] runnable tasks:
task PID tree-key switches prio
wait-time sum-exec sum-sleep
----------------------------------------------------------------------------------------------------------
The kernel timestamps each of these lines with [965199.028940] and the
dmesg utility should do the same.
Add the 'force-prefix'/'-p' dmesg option to add decode & timestamp
information to each line of a multi-line message.
Notes: The new print_record() algorithm stores the decode & timestamp
information in buffers. If the force-prefix option is used, the
message is split into separate lines and each line is prefixed with
the stored decode & timestamp information. The splitting of the
message into separate lines is done using strtok() which requires
write access to the message buffer (ie, the const message buffer is
now copied into a writeable buffer).
Successfully tested by me by looking at sysrq-t and sysrq-w output.
All known good /tests passed with these changes.
[kzak@redhat.com:
- use snprintf()
- cleanup \n usage (don't count line break to the
message text in the parsers and always print \n after the text
- add the option to the man page
- use --force-prefix for kmsg only, old syslog(2) API splits messages itself
- strdup() the message text only on force-prefix]
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
changed in include/c.h and applied via sed:
sed -i 's/fprintf.*\(USAGE_MAN_TAIL.*\)/printf(\1/' $(git ls-files -- "*.c")
sed -i 's/print_usage_help_options\(.*\);/printf(USAGE_HELP_OPTIONS\1);/' $(git ls-files -- "*.c")
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
Now we are always using the same text also for commands
which had still hardcoded descriptions or where we can't
use the standard print_usage_help_options macro.
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
Consolidate --help and --version descriptions. We are
now able to align them to the other options.
We changed include/c.h. The rest of this patch was
generated by sed, plus manually setting the right
alignment numbers. We do not change anything but
white spaces in the --help output.
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
* 'usage-part1' of https://github.com/rudimeier/util-linux:
misc: no more errtryh()
mkfs.cramfs: add --help and --version
more: add --help and --version
whereis: add --help and --version
login: add --help and --version
fsck: add --help and --version
setarch: use errtryhelp()
dmesg: do not accept any non-option arguments
blkid: use errtryhelp instead of errtryh
misc: remove superfluous null pointer checks for optarg
uuidd: remove unused define
'dmesg foo' is no valid syntax and gives an error now.
BTW we avoid the "dead increment of argc and argv.
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
As buf is passed as a signed char buffer in fwrite_hex, fprintf will
print every byte from 0x80 as a signed-extended int causing each of
these bytes to be printed as "\xffffff80" and such, which can be pretty
confusing. Force fprintf to use the argument as a char to make it print
only 2 digits, e.g. "\x80".
Signed-off-by: Ivan Delalande <colona@arista.com>
When extended console is enabled, the kernel doesn't internally
concatenate message fragments, this change adds log fragment
concatenation to dmesg: instead of being printed as separate messages,
fragments are combined onto one line and printed with the timestamp of
the first line.
This doesn't work in all cases - such as if another message is logged in
between two fragment lines, but in this case the behavior matches the
previous output format (printed on the separate lines).
[kzak@redhat.com: - rename kmsg_read_buf to kmsg_saved_size,
- minor coding style fixes]
Signed-off-by: Vinnie Magro <vmagro@fb.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
* clean up function names
* add functions to temporary redirect to the pager and then restore
original terminal output
Signed-off-by: Karel Zak <kzak@redhat.com>
Fix various typos in error messages, warnings, debug strings,
comments and names of static functions.
Signed-off-by: Sebastian Rasmussen <sebras@gmail.com>
The --show-delta is off by default, which means it can be only on when user
has requested to see these time stamps. The --notime option should not turn
the delta outputing off, because then option order matters and no-one wants
that. Example of the old output:
$ dmesg --notime --show-delta | sed -n 's/ version.*//p; q'
[< 0.000000>] Linux
$ dmesg --show-delta --notime | sed -n 's/ version.*//p; q'
Linux
Addresses: https://bugs.launchpad.net/bugs/1544595
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
sys-utils/dmesg.c:650:9: warning: declaration of 's' shadows a previous local [-Wshadow]
sys-utils/dmesg.c:619:12: warning: shadowed declaration is here [-Wshadow]
And since the code had to be touched deprecate loop printing one character
at a time, in favour of printf and instruction to repeat spaces the number
required.
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
The message "stat failed %s" seems to say that stat() failed to
do something, or failed to pass a test, but of course it means
that the statting of something failed. So say so. Also make
two very similar messages equal to this one.
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>
Karel Zak
Yuri Chornoivan
Konstantin Khlebnikov
Sami Kerola
Ruediger Meier
J William Piggott
Prarit Bhargava
Ivan Delalande
Vinnie Magro
Yuri Chornoivan
Sebastian Rasmussen
Benno Schulenberg