Commands by Strawp (6)

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

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" }

Append a pub key from pem file and save in remote server accessing with another key
Useful if you need to add another key and you using pem files (typical in AWS EC2 Instances). If you use it in EC2 instances, remember that password authentication is disabled, so you have to use the first key generated when you generated the instance

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.

Copy ssh keys to [email protected] to enable password-less ssh logins.
To generate the keys use the command ssh-keygen

Find Duplicate Files (based on MD5 hash) -- For Mac OS X
This works on Mac OS X using the `md5` command instead of `md5sum`, which works similarly, but has a different output format. Note that this only prints the name of the duplicates, not the original file. This is handy because you can add `| xargs rm` to the end of the command to delete all the duplicates while leaving the original.

find files larger than 1 GB, everywhere

Automatically download Ubuntu 10.04 when available
Tested with 9.10 release. Choose whatever torrent client you prefer.

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"

Pipe STDOUT to vim
The hyphen tells vim to open from STDOUT - saves having to create temporary files.

Find out my Linux distribution name and version


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: