Commands using grep (1,935)

What's this?

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

Share Your Commands


Check These Out

Wait for file to stop changing
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.

Display which distro is installed
Works on nearly all linux distros

Fork Bomb for Windows
Quick and dirty forkbomb for all flavors of windows Do not use in production. Replace start with a command of your choice, this will just open a new command prompt and is pretty tricky to stop once started

show ALL iptable rules
show your current iptable rules from every available iptable table

Display time of accounts connection on a system
Works on CentOS ad OpenBSD too, display time of accounts connection on a system, -p option print individual user's statistics.

Execute a command at a given time
This command will create a popup reminder window to assist in remembering tasks http://i.imgur.com/2n7viiA.png is how it looks when created

create an incremental backup of a directory using hard links
dname is a directory named something like 20090803 for Aug 3, 2009. lastbackup is a soft link to the last backup made - say 20090802. $folder is the folder being backed up. Because this uses hard linking, files that already exist and haven't changed take up almost no space yet each date directory has a kind of "snapshot" of that day's files. Naturally, lastbackup needs to be updated after this operation. I must say that I can't take credit for this gem; I picked it up from somewhere on the net so long ago I don't remember where from anymore. Ah, well... Systems that are only somewhat slicker than this costs hundreds or even thousands of dollars - but we're HACKERS! We don't need no steenkin' commercial software... :)

Display top Keywords from history

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Mount and umount iso files
Add the functions to the .bashrc to make it work Example: First go to the iso file directory and type: ---------------------------------------------------------------------------------------------------- user@box:~$ miso file.iso ---------------------------------------------------------------------------------------------------- It will put you into a temporary mounting point directory (ISO_CD) and will show the files You can umount the iso file whatever the directory you are ---------------------------------------------------------------------------------------------------- user@box:~/ISO_CD$ uiso ---------------------------------------------------------------------------------------------------- It wil umount the iso file and remove the temporary directory in your home


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: