Hide

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.

Hide

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:

Hide

News

2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.
Hide

Tags

Hide

Functions

Backup a file with a date-time stamp

Terminal - Backup a file with a date-time stamp
buf() { cp -v $1 ${1/${1%%.*}/$f-$(date +"%Y%m%d_%H%M%S")};}
2010-12-15 12:16:03
User: unefunge
Functions: cp date
0
Backup a file with a date-time stamp

even shorter (infix) version.

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
buf () { cp $1{,$(date +%Y%m%d_%H%M%S)}; }
2010-12-14 14:02:03
User: unefunge
Functions: cp date
2

1. you don't need to prepend the year with 20 - just use Y instead of y

2. you may want to make your function a bit more secure:

buf () { cp ${1?filename not specified}{,$(date +%Y%m%d_%H%M%S)}; }

buf () { filename=$1; filetime=$(date +%Y%m%d_%H%M%S); cp ${filename} ${filename}_${filetime}; }
2010-12-14 13:19:52
User: dopeman
Functions: cp date
1
buf myfile.txt

This is useful when you are making small but frequent changes to a file. It keeps things organised and clear for another administrator to see what changed and at what time. An overview of changes can be deduced using a simple:

ls -ltr
buf () { oldname=$1; if [ "$oldname" != "" ]; then datepart="$(date +%Y-%m-%d).bak"; firstpart=`echo $oldname | cut -d "." -f 1`; newname=`echo $oldname | sed s/$firstpart/$firstpart.$datepart/`; cp -iv ${oldname} ${newname}; fi }
2012-08-15 08:31:44
User: juliushibert
Functions: cp cut sed
1

Appends the input file with the date format YYYY-MM-DD.bak. Also runs silently if you remove the -v on the cp at the end of the function.

buf() { f=${1%%.*};e=${1/$f/};cp -v $1 $f-$(date +"%Y%m%d_%H%M%S")$e;}
2010-12-15 09:50:04
User: unefunge
Functions: cp date
0

"infix" version in bash (4.x+)

Remove -v to make it silent.

BTW: The OP forgot to use "cat" and "nmap" ;-) I had a good laugh though.

buf () {oldname=$1; if [ "$oldname" != "" ]; then datepart=$(date +%Y-%m-%d); firstpart=`echo $oldname | cut -d "." -f 1`; newname=`echo $oldname | sed s/$firstpart/$firstpart.$datepart/`; cp -i ${oldname} ${newname}; fi }
2010-12-14 19:58:34
User: Seebi
Functions: cp cut date sed
-3

This backup function preserve the file suffix allowing zsh suffix aliases and desktop default actions to work with the backup file too.

Know a better way?

If you can do better, submit your command here.

Your point of view

You must be signed in to comment.

Related sites and podcasts