Get Directory Recursive Last Modified Date – Bash Script Guide

bashfilesshell-scripttimestamps

I would like to know a command or function in linux bash to get the timestamp (and maybe format its output) of the last modified file inside a directory.

Let's say I have /path/mydir and this directory has a big bunch of files inside. Given its path, I want to output the timestamp of the most recent modified file.

I guess that the procedure could be do a foreach file recursive, check them all and update a variable with the most recent time each time a more recent one is found.

Edit: Sorry for the confusion but I wanted to intend the Epoch timestamp 🙂

Best Answer

One option: use GNU find to recurse through all files; print timestamp with filepath and sort by date:

find /path/mydir -type f -printf "%T+\t%p\n" | sort | tail -1

For just the epoch timestamp,

find /path/mydir -type f -printf "%T@\n" | sort | tail -1

Related Solutions

Shell – Leap seconds and date

I didn't find a simple solution to my question, so I've written a small Bash script to solve it. You need to download the leap seconds file given in the link below and put it with the script or change the path to it. I didn't write utc2unix.sh yet, but it's very easy to adapt. Do not hesitate to comment/give suggestions...

unix2utc.sh:

#!/bin/bash

# Convert a Unix timestamp to the real number of seconds
# elapsed since the epoch.

# Note: this script only manage additional leap seconds

# Download leap-seconds.list from
# https://github.com/eggert/tz/blob/master/leap-seconds.list

# Get current timestamp if nothing is given as first param
if [ -z $1 ]; then
    posix_time=$(date --utc +%s)
else
    posix_time=$1
fi

# Get the time at which leap seconds were added
seconds_list=$(grep -v "^#" leap-seconds.list | cut -f 1 -d ' ')

# Find the last leap second (see the content of leap-seconds.list)
# 2208988800 seconds between 01-01-1900 and 01-01-1970:
leap_seconds=$(echo $seconds_list | \
               awk -v posix_time="$posix_time" \
               '{for (i=NF;i>0;i--)
                   if (($i-2208988800) < posix_time) {
                    print i-1; exit
                    }
                } END {if (($(i+1)-2208988800) == posix_time) 
                    print "Warning: POSIX time ambiguity:",
                            posix_time,
                          "matches 2 values in UTC time!",
                          "The smallest value is given." | "cat 1>&2"
                }')
# echo $leap_seconds

# Add the leap seconds to the timestamp
seconds_since_epoch=$(($posix_time + $leap_seconds))

echo $seconds_since_epoch

Just some tests:

date --utc +%s && ./unix2utc.sh -> today and at least until June 2015 the difference is 25 sec.
./unix2utc.sh 78796799 -> 78796799
./unix2utc.sh 78796801 -> 78796802
./unix2utc.sh 78796800 -> 78796800 + on stderr: Warning: POSIX time ambiguity: 78796800 matches 2 consecutive values in UTC time! Only the smallest value is given.

Shell – CLI equivalent of Gnome’s recent files feature

This will take the recently-used files referenced in ~/.local/share/recently-used.xbel (or rather, ${XDG_DATA_HOME}/recently-used.xbel), and link them all into a directory called ~/recent:

#!/bin/sh
set -e
mkdir -p ~/recent
rm -f ~/recent/*       # Make sure you don’t have anything you care about here
xmlstarlet sel -t -m '/xbel/bookmark[starts-with(@href, "file://")]' \
    -v 'substring(@href, 8)' -n ${XDG_DATA_HOME:-~/.local/share}/recently-used.xbel |
python -c "import sys, urllib as ul;
sys.stdout.write(ul.unquote(sys.stdin.read().replace('\n', '\0')));" |
xargs -0 ln -st ~/recent

This uses XMLStarlet to extract the file URIs from the list of recently-used documents (ignoring other URIs), feeds them to a Python script which replaces newlines with nul characters and then unquotes the escaped URIs (e.g. + or %20 instead of space), and finally feeds that to xargs which splits all the file names and feeds them to ln (the GNU variant) to create symbolic links.

Note that links will be created regardless of whether the target file still exists; it often happens that the list of recently-used files includes temporary files which have since been deleted.

Best Answer

Related Solutions

Shell – Leap seconds and date

Shell – CLI equivalent of Gnome’s recent files feature

Related Question