What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

Universal configuration monitoring and system of record for IT.

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:



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!

Top Tags





Commands using cal from sorted by
Terminal - Commands using cal - 18 results
: $(cal [$month $year]) ; echo $_
YYYY=2014; MM=02; for d in $(cal $MM $YYYY | grep "^ *[0-9]"); do DD=$(printf "%02d" $d); echo $YYYY$MM$DD; done
2014-02-06 11:31:57
User: fibo
Functions: cal echo grep printf
Tags: cal for loop

Edit YYYY and MM at the beginning of the command with the year and month you want.

Note that `DD=$(printf "%02d" $d)` will pad single digit integers with a leading zero.

Substitute `echo $YYYY$MM$DD` at the end of the line with the command you want to launch, for instance

script.pl --yyyymmdd $YYYY$MM$DD

for y in {2009..2013}; do cal $y; done
cal | grep -E --color "\b`date +%e`\b|$"
2012-06-27 20:30:40
User: donjuanica
Functions: cal grep
Tags: calendar

The cal command is handy, but sometimes you want to quickly see today's date highlighted. That's why I came up with this quick command.

Much like http://www.commandlinefu.com/commands/view/1342/show-this-months-calendar-with-todays-date-highlighted but cleaner and more succinct.

cal 04 2012 | awk '{ $7 && X=$7 } END { print X }'
2012-05-06 23:43:21
User: flatcap
Functions: awk cal

If your locale has Monday as the first day of the week, like mine in the UK, change the two $7 into $6

cal 04 2012 | awk 'NF <= 7 { print $7 }' | grep -v "^$" | tail -1
2012-05-03 16:57:45
User: javidjamae
Functions: awk cal grep tail

This is a little trickier than finding the last Sunday, because you know the last Sunday is in the first position of the last line. The trick is to use the NF less than or equal to 7 so it picks up all the lines then grep out any empty lines.

cal | egrep -e '^ [0-9]|^[0-9]' | tr '\n' ' ' | awk '{print $NF}'
2012-04-16 11:58:09
User: gouverney
Functions: awk cal egrep tr

Returns last day of current month. Useful to implement a bash script backup based on a GFS strategy.

cal | grep -C7 --color=auto $(date +%d)
2011-11-29 11:35:41
User: cjp64
Functions: cal date grep

Slightly shorter to type

cal |grep -A7 -B7 --color=auto $(date +%d)
2011-11-26 22:13:12
User: 4fthawaiian
Functions: cal date grep

Displays the same output as "cal", but with the current day highlighted (probably dependent on gnu grep, as I'm not sure other grep's support the "--color=auto" option). Tested and working on Ubuntu 11 and OSX Lion.

cal | sed -E "2,8s/(^|[^0-9])($(date +%e))( |$)/\1$(echo "\033[0;36m\2\033[0m")\3/g"
2011-04-30 03:16:31
User: iridium172
Functions: cal sed

Colors a the current date in cal output

cal -y
2009-09-02 12:57:23
User: andrepuel
Functions: cal

Show today date on a yearly calendar.

for y in $(seq 2009 2011); do cal $y; done
2009-07-10 10:07:46
Functions: cal seq
Tags: bash seq cal

print multiple increasing years using cal - calendar -. You can also try

seq Start Increment End
for y in 2009 2010 2011; do cal $y; done
cal -y | tr '\n' '|' | sed "s/^/ /;s/$/ /;s/ $(date +%e) / $(date +%e | sed 's/./#/g') /$(date +%m | sed s/^0//)" | tr '|' '\n'
cal 09 1752
2009-04-22 00:13:19
User: flux
Functions: cal
Tags: date fun

The British Government entering in the Gregorian era.

cal -3
2009-04-02 17:40:38
User: haivu
Functions: cal
Tags: PIM

the -3 show the previous, current, and next month.

cal | grep --before-context 6 --after-context 6 --color -e " $(date +%e)" -e "^$(date +%e)"
2009-03-04 06:46:52
User: haivu
Functions: cal grep
Tags: PIM


* The date command evaluated to today's date with blank padded on the left if single digit

* The grep command search and highlight today's date

* The --before-context and --after-context flags displays up to 6 lines before and after the line containing today's date; thus completes the calendar.

I have tested this command on Mac OS X Leopard and Xubuntu 8.10

cal [[month] year]