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May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

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Commands using date from sorted by
Terminal - Commands using date - 171 results
echo "$(obase=16; echo "$(date +%s)" | bc | xxd -r -p | base32)"
stf=$(date +%s.%N);for ((;;));do ctf=$( date +%s.%N );echo -en "\r$(date -u -d "0 $ctf sec - $stf sec" "+%H:%M:%S.%N")";done
stf=$(date +%s.%N);st=${stf/.*/};sn=%{stf/*./};for ((;;));do ctf=$( date +%s.%N );ct=${ctf/.*/};cn=${ctf/*./}; dtf=$(echo "scale=3; $ctf-$stf" | bc); dt=${dtf/.*/}; dt=${dt:=0};echo -en "\r$(date -u -d @$dt "+%H:%M:%S.${dtf/*./}")";done
stf=$(date +%s.%N);st=${stf/.*/};sn=%{stf/*./};for ((;;));do ctf=$( date +%s.%N );ct=${ctf/.*/};cn=${ctf/*./}; echo -en "\r$(echo "scale=3; $ctf-$stf" | bc)";done
2017-01-26 13:20:30
User: glaudiston
Functions: date echo
Tags: chronometer

A way for tracking times in bash

while true ; do fswebcam -d /dev/video0 -r 1280x1024 -F 15 - | uuencode $(date +\%Y\%m\%d\%H\%M).jpeg | mail -s "Video surveillance" [email protected] ; sleep 300 ; done
2016-08-09 14:22:45
User: pascalv
Functions: date mail sleep true uuencode

This takes a picture (with the web cam) every 5 minutes, and send the picture to your e-mail.

Some systems support

mail -a "References: "

so that all video surveillance emails are grouped in a single email thread.

To keep your inbox clean, it is still possible to filter and move to trash video surveillance emails (and restore these emails only if you really get robbed!)

For instance with Gmail, emails sent to [email protected] can be filtered with "Matches: DeliveredTo:[email protected]"

curl --silent --head "${url}" | grep 'Last-Modified:' | cut -c 16- | date -f - +'%s'
2016-06-02 22:20:55
User: odoepner
Functions: cut date grep

This command line assumes that "${url}" is the URL of the web resource.

It can be useful to check the "freshness" of a download URL before a GET request.

sajb {$ip="";$old=0;while(1){$up=test-connection -quiet -count 1 $ip;if($up-ne$old){$s=(date -u %s).split('.')[0]+' '+(date -f s).replace('T',' ')+' '+$ip+' '+$(if($up){'Up'}else{'Down'});echo $s|out-file -a $home\ping.txt;$old=$up}sleep 10}}

IMPORTANT: You need Windows PowerShell to run this command - in your Windows Command Prompt, type


Uses sajb to start a PowerShell background job that pings an IP host every 10 seconds.

Any changes in the host's Up/Down state is time-stamped and logged to a file.

Date/time stamps are logged in two formats: Unix and human-readable.

A while(1) loop repeats the test every 10 seconds by using the sleep command.

See the Sample Output for more detail.

I use this command to log Up/Down events of my Motorola SB6141 cable modem (

To end the logging, close the PowerShell window or use the "exit" command.

while(1){while((date -f ss)%10-gt0){sleep -m 300} echo "$(date -u %s) $((curl|%{$_ -replace '\D+\n',''})">>modemlog.txt;sleep 1;echo .}
2015-12-24 02:12:10
User: omap7777
Functions: date echo sleep

IMPORTANT: You need Windows PowerShell to run this command - in your Windows Command Prompt, type


Create a log file of your Motorola Surfboard SB6141 downstream signal strengths.

Uses the built-in curl to request signal strength data from your SB6141 cable modem.

HTML page has the signal strength numbers for the 8 downstreams.

Some HTML/DOM processing parses out the 8 values from the above page.

The eight extracted signal strengths are then logged to a file.

A small while-loop watches the clock & repeats the process every 10 seconds.

while true; do (echo -n $(date +"%F %T"):\ ; xwininfo -id $(xprop -root|grep "ACTIVE_WINDOW("|cut -d\ -f 5) | grep "Window id" | cut -d\" -f 2 ) >> logfile; sleep 60; done
2015-09-23 23:00:14
User: BeniBela
Functions: cut date echo grep sleep

This logs the titles of the active windows, thus you can monitor what you have done during which times. (it is not hard to also log the executable name, but then it is gets too long)

[ $(date +"%H") -lt 7 ] && echo you should probably be sleeping...
sed -i.$(date +%F@%T) 's/^LogLevel warn/LogLevel debug/g' httpd.conf
2015-07-22 14:47:26
User: zlemini
Functions: date sed

httpd.conf [email protected]:43:20

if [[ $(expr $(date +%s) - $(stat -c %X /var/lib/apt/periodic/update-success-stamp)) -gt 86400 ]]; then sudo apt-get update fi
2015-05-12 14:45:11
User: gargolito
Functions: date expr stat sudo

I have this in my .bash_aliases and call it before running apt-get install or apt-get upgrade


alias apt-install='apt-update; apt-get install'

alias apt-upgrade='apt-update; apt-get upgrade'

function apt-update () {

if [[ $(expr $(date +%s) - $(stat -c %X /var/lib/apt/periodic/update-success-stamp)) -gt 86400 ]]; then

sudo apt-get update


echo apt is up to date



while [ $(( $(date +%s) - $(stat -c %Y FILENAME) )) -lt 10 ]; do sleep 1; done; echo DONE
2015-05-09 12:30:13
User: flatcap
Functions: date echo sleep stat

This loop will finish if a file hasn't changed in the last 10 seconds.


It checks the file's modification timestamp against the clock.

If 10 seconds have elapsed without any change to the file, then the loop ends.


This script will give a false positive if there's a 10 second delay between updates,

e.g. due to network congestion


How does it work?

'date +%s' gives the current time in seconds

'stat -c %Y' gives the file's last modification time in seconds

'$(( ))' is bash's way of doing maths

'[ X -lt 10 ]' tests the result is Less Than 10

otherwise sleep for 1 second and repeat


Note: Clever as this script is, inotify is smarter.

echo $(date +%m) past $(date +%H) | espeak
2015-05-09 12:24:13
User: hal8
Functions: date echo

s/espeak/say/ on a mac

clear; while sleep 1; do d=$(date +"%H:%M:%S"); e=$(echo "toilet -t -f mono12 $d");tput setaf 1 cup 0; eval $e; tput setaf 4 cup 8; eval "$e -F flop";tput cup 0; done
ssh [email protected] sudo date -s @`( date -u +"%s" )`
crontest () { date +'%M %k %d %m *' |awk 'BEGIN {ORS="\t"} {print $1+2,$2,$3,$4,$5,$6}'; echo $1;}
2015-03-12 19:56:56
User: CoolHand
Functions: awk date echo

usage = crontest "/path/to/bin"

This version of this function will echo back the entire command so it can be copied/pasted to crontab. Should be able to be automagically appended to crontab with a bit more work. Tested on bash and zsh on linux,freebsd,aix

for file in $(find /var/backup -name "backup*" -type f |sort -r | tail -n +10); do rm -f $file; done ; tar czf /var/backup/backup-system-$(date "+\%Y\%m\%d\%H\%M-\%N").tgz --exclude /home/dummy /etc /home /opt 2>&- && echo "system backup ok"
2014-09-24 14:04:11
User: akiuni
Functions: date echo file find rm sort tail tar
Tags: backup Linux cron

this command can be added to crontab so as to execute a nightly backup of directories and store only the 10 last backup files.

date -r 1390196676
function findOlderThan () { find . -mmin -$((($(date "+%s") - $(stat -c %Y $1))/60)) -type f ; }
2014-08-29 17:52:34
User: RobertDeRose
Functions: date find stat
Tags: find date stat

This function will find the modification time in unix_time of the given file, then calculate the number of minutes from now to then and then find all files modified in that range.

YEAR=2015; date -d${YEAR}0801-$(date -d${YEAR}0801+2days +%u)days +%b\ %e
2014-08-17 11:06:25
User: andreasS
Functions: date
Tags: date

Calculate Sysadmin day of any given year using 2 `date`. Code based on http://stackoverflow.com/a/5656859/196133

[ `curl 'http://crl.godaddy.com/gds5-16.crl' 2>/dev/null | openssl crl -inform DER -noout -nextupdate | awk -F= '{print $2}' | xargs -I{} date -d {} +%s` -gt `date -d '8 hours' +%s` ] && echo "OK" || echo "Expires soon"
2014-08-07 17:18:38
User: hufman
Functions: awk date echo xargs
Tags: openssl

Downloads a CRL file, determines the expiration time, and checks when it will expire

echo {-1..-5}days | xargs -n1 date +"%Y-%m-%d" -d
date -d @1268727836
2014-05-19 09:53:03
Functions: date

The easiest way to convert epoch date to human readable format.

$ date [email protected]'