dategrep - print lines matching a date range
dategrep --start "12:00" --end "12:15" syslog dategrep --end "12:15" --format "%b %d %H:%M:%S" syslog dategrep --last-minutes 5 syslog cat syslog | dategrep --end "12:15"
Do you even remember how often in your life you needed to find lines in a log file falling in a date range? And how often you build brittle regexs in grep to match entries spanning over a hour change?
dategrep hopes to solve this problem once and for all.
If dategrep works on a normal file, it can do a binary search to find the first and last line to print pretty efficiently. dategrep can also read from stdin and compressed files, but as it can't do any seeking in those files, we have to parse every line until we find the first falling in our date range. But at least we don't have to wait for the pipe to be closed. As soon as we find the first date not in the range, dategrep terminates.
See UPGRADING if you used dategrep before. dategrep sees currently a lot of change, so this version might be less reliable as version 0.58. Please submit bug reports if anything unusual happens.
But just let me show you a few examples.
Without any parameter dategrep matches all lines from epoch to the time it started. In this case it's just a glorified cat that knows when to stop.
dategrep syslog
But things start to get interesting if you add the start and end options.
dategrep --start 12:00 --end 12:15 syslog
If you leave one out it again either defaults to epoch or now.
dategrep --end 12:15 syslog
Dategrep knows how to handle common time formats like apaches standard english format and rsyslog. If you need to handle a new format, you can use --format:
dategrep --format "%b %d %H:%M:%S" syslog
If your like me, you often need to call dategrep from cron and need to get all lines from the last five minutes. So there's an easy shortcut for that.
dategrep --last-minutes 5 syslog
Pipes or zipped files can also be handled, but those will be slower to filter. It's often more efficient to just search on an unzipped file or redirect the lines from the pipe to file first. But nothing is stopping you to just call dategrep directly.
cat syslog | dategrep --end 12:15 dategrep --end 12:15 syslog.gz
Print all lines from DATESPEC inclusively. Defaults to Jan 1, 1970 00:00:00 GMT.
The following time formats are understood:
All dates formats without date specifiers default to today.
Additional it's possible to express offsets against dates by using the special syntax $date truncate ... add ..., for example
--from "now truncate 1h add 17m" --to "now truncate 1h add 1h17m"
would search entries from 16:17 to 17:17 if the current time was 17:30.
Print all lines until DATESPEC exclusively. Defaults to the current time. See --start for a list of possible formats for DATESPEC.
Print all lines from MINUTES minutes ago until the beginning of the current minute. So if we have 19:25:43 and MINUTES is five, dategrep will print all lines from 19:20:00 to 19:24:59.
Defines a time format that is used to parse the input lines for a date. The time format string can contain the conversion specifications described in the strptime(3) manual page. Currently only the specifiers "AaBbcHMSdDIlmnYzZRrTFehkCyXx%" are supported.
This option can be given multiple times. In this case dategrep tries every format in the order given until it can match a line.
Without a user supplied format, dategrep tries all time formats it knows about.
Alternatively you can supply the format via the environment variable DATEGREP_DEFAULT_FORMAT.
Print all lines between the start and end line even if they are not timestamped.
Ignore all lines without timestamp. Disables --multiline.
SIZE of the intervals used in the binary search. Defaults to the native blocksize of the file's filesystem or 8129.
Print lines sorted by timestamp even if the timestamps in the input files are overlapping.
Sort files in the order of the first line with a timestamp. For example: If you have a common logrotate configuration, you probably have files like syslog, syslog.1, syslog.2 etc. For dategrep to work we need those files in reverse order: syslog.2, syslog.1, syslog. This options handles that for you.
Shows a short help message
Shows the complete man page in your pager.
Default for the --format parameter. The syntax is described there.
dategrep has only minimal support for compressed files. If any file in ARGV has an extension like .z,.gz,.bz2,.bz, dategrep will call zcat or bzcat respectively and read from it like from stdin.
dategrep expects the files to be sorted. If the timestamps are not ascending, dategrep might be exiting before the last line in its date range is printed.
Compressed files are just piped into dategrep via bzcat or zcat.
strptime(3)
It is possible to install this script via perl normal install routines.
perl Build.PL && ./Build && ./Build install
Or via CPAN:
cpan App::dategrep
dategrep after version 0.58 uses a new library to parse dates. Most time conversion specifiers are compatible, but it's probably better to check the manual for valid specifiers. In addition the format for specifying date offsets has changed.
Copyright 2014 Mario Domgoergen <mario@domgoergen.com>
<mario@domgoergen.com>
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.
To install App::dategrep, copy and paste the appropriate command in to your terminal.
cpanm
cpanm App::dategrep
CPAN shell
perl -MCPAN -e shell install App::dategrep
For more information on module installation, please visit the detailed CPAN module installation guide.