ack/grep search and sort by modification date

Question

Is there any way to have ack sort the results found by date of modification? (ideally showing the date next to the result?). It doesn't look like ack has a date option, but just in case.

If this isn't possible with ack, how about grep or using a combination of tools?

Answer 1

Neither ack or grep have any notion of a file's modification dates. For that you'll need to generate the list of files first, and then sort them based on afterwards.

You can use xargs to run the output of either ack or grep into another command which will provide the modification dates. For the modification dates you can use stat to do that.

Example

$ grep -Rl awk * | xargs -n 1 stat --printf "%y ------ %n\n"
2013-11-12 10:06:16.000000000 -0500 ------ 100855/tst_ccmds.bash
2013-11-13 00:32:11.000000000 -0500 ------ 100911/cmd.bash
2013-11-23 03:16:17.000000000 -0500 ------ 102298/cmd.bash
2013-12-14 20:06:04.467708173 -0500 ------ 105159/cmd.txt
2013-12-16 03:20:48.166016538 -0500 ------ 105328/cmds.txt
2013-01-14 14:17:39.000000000 -0500 ------ 106932/red5-1.0.1.tar.gz

NOTE: This method will only show you the names of the files that matched your query along with the modification date.

Answer 2

With GNU tools:

grep -H something * | awk -F: '{"date -r \""$1"\" +\"%F %R\"" | getline d; print d,$0}' | sort -n

Or,

ack something | awk -F: '{"date -r \""$1"\" +\"%F %R\"" | getline d; print d,$0}' | sort -n

This uses awk to separate out the file name from the usual grep output and awk calls date to retrieve the files date. grep is given the -H option to assure that a filename is shown on output even if only one appears on the command line.

As an example of the output:

$ grep setupcon /etc/init.d/* | awk -F: '{"date -r \""$1"\" +\"%F %R\"" | getline d; print d,$0}' | sort -n
2011-12-05 12:05 /etc/init.d/keymap.sh:# If setupcon is present, then we've been superseded by console-setup.
2011-12-05 12:05 /etc/init.d/keymap.sh:if type setupcon >/dev/null 2>&1; then
2011-12-08 18:00 /etc/init.d/console-setup:     if setupcon --save; then
2011-12-08 18:00 /etc/init.d/console-setup:test -f /bin/setupcon || exit 0
2012-04-28 02:41 /etc/init.d/kbd:if which setupcon >/dev/null
2012-09-30 18:02 /etc/init.d/keyboard-setup:    if setupcon -k 2>/dev/null; then
2012-09-30 18:02 /etc/init.d/keyboard-setup:test -f /bin/setupcon || exit 0

Explanation of awk commands

• -F:

  This sets the field separator to : so that the first field is the file name. (We have to hope that the file name itself does not contain a colon.)

• "date -r \""$1"\" +\"%F %R\"" | getline d

  This runs date -r filename +"%F %R" to get the file's modification date in a form suitable for sorting. The date is stored in the variable d.

• print d,$0

  This prints the data followed by the line of output from grep.