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

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Copy ssh keys to user@host to enable password-less ssh logins.
Alternative for machines without ssh-copy-id

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

List of reverse DNS records for a subnet
This command uses nmap to perform reverse DNS lookups on a subnet. It produces a list of IP addresses with the corresponding PTR record for a given subnet. You can enter the subnet in CDIR notation (i.e. /24 for a Class C)). You could add "--dns-servers x.x.x.x" after the "-sL" if you need the lookups to be performed on a specific DNS server. On some installations nmap needs sudo I believe. Also I hope awk is standard on most distros.

Suspend an ssh session.
This must be typed before any other characters have been entered on the line. Use fg, as usual, to resume the ssh session.

Create a simple video contact sheet using the vcs bash script
Assumes you've downloaded Toni Corvera's vcs script (http://p.outlyer.net/vcs), have it in your PATH, and have installed the script's dependencies. Generates a video contact sheet of 24 thumbnails and 3 thumbnails per column. The bold font and white-on-black color scheme keeps the text readable at the chosen 70% JPEG compression quality, which keeps the file size at a manageable level. You can go even lower with the quality and get a good looking result.

Windows telnet
Check if TCP port is reacheable

Get your public ip using dyndns

Get the 10 biggest files/folders for the current direcotry
This command simply outputs 10 files in human readable, that takes most space on your disk in current directory.

apt-get upgrade with bandwidth limit
in Debian-based systems apt-get could be limited to the specified bandwidth in kilobytes using the apt configuration options(man 5 apt.conf, man apt-get). I'd quote man 5 apt.conf: "The used bandwidth can be limited with Acquire::http::Dl-Limit which accepts integer values in kilobyte. The default value is 0 which deactivates the limit and tries uses as much as possible of the bandwidth..." "HTTPS URIs. Cache-control, Timeout, AllowRedirect, Dl-Limit and proxy options are the same as for http..."


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: