All commands (14,187)

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

Find Duplicate Files (based on size first, then MD5 hash)
Finds duplicates based on MD5 sum. Compares only files with the same size. Performance improvements on: $find -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate The new version takes around 3 seconds where the old version took around 17 minutes. The bottle neck in the old command was the second find. It searches for the files with the specified file size. The new version keeps the file path and size from the beginning.

find large files

VIM: when Ctrl-D and Ctrl-U only scroll one line, reset to default
Resets the scroll parameter to the default (half the rows in the current window). The scroll parameter can be inadvertently set to 1, e..g., if you type '1 Ctrl-D' or '1 Ctrl-U' in normal mode.

Set pcap & SUID Bit for priv. network programs (like nmap)

Make vim open in tabs by default (save to .profile)
I always add this to my .profile rc so I can do things like: "vim *.c" and the files are opened in tabs.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

put all lines in comment where de word DEBUG is found

Show the power of the home row on the Dvorak Keyboard layout
Quick and dirty command that counts how many words can be typed just using the home row on the Dvorak Simplified Keyboard layout from a dictionary file, in this case /usr/share/dict/words. According to the regular expression supplied, each word must contain all the keys on the Dvorak home row, and no other characters. For comparison, I've shown how many words are installed in my dictionary, how many can be typed with just the Dvorak home row and how many can be typed with just the QWERTY home row in the sample output. Nearly 10 times the amount. If you want to see the words, remove the -c switch, and each word will be printed out.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Create a thumbnail from a video file


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: