Commands by bjomape (1)

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

Create a list of binary numbers
If you should happen to find yourself needing some binary numbers, this is a quickie way of doing it. If you need more digits, just add more "{0..1}" sequences for each digit you need. You can assign them to an array, too, and access them by their decimal equivalent for a quickie binary to decimal conversion (for larger values it's probably better to use another method). Note: this works in bash, ksh and zsh. For zsh, though, you'll need to issue a setopt KSH_ARRAYS to make the array zero-based. $ binary=({0..1}{0..1}{0..1}{0..1}) $ echo ${binary[9]}

repeat any string or char n times without spaces between
(here is character '+' repeated 80 times) Sometimes needed to enhance the title of the script.

Increment the filename of png in a given directory by one

split source code to page with numbers

Schedule Nice Background Commands That Won't Die on Logout - Alternative to nohup and at
Check out the usage of 'trap', you may not have seen this one much. This command provides a way to schedule commands at certain times by running them after sleep finishes sleeping. In the example 'sleep 2h' sleeps for 2 hours. What is cool about this command is that it uses the 'trap' builtin bash command to remove the SIGHUP trap that normally exits all processes started by the shell upon logout. The 'trap 1' command then restores the normal SIGHUP behaviour. It also uses the 'nice -n 19' command which causes the sleep process to be run with minimal CPU. Further, it runs all the commands within the 2nd parentheses in the background. This is sweet cuz you can fire off as many of these as you want. Very helpful for shell scripts.

Tar files matching a certain wildcard
This is a shortcut to tar up all files matching a wildcard. Tar doesn't have the --include (apparently).

Tree based ps view "painted" by ccze

return external ip
curl inet-ip.info -> 113.33.232.62\n curl inet-ip.info/ip -> 113.33.232.62 curl inet-ip.info/json -> JSON print curl inet-ip.info/json/indent -> JSON pretty print curl inet-ip.info/yaml -> YAML format curl inet-ip.info/toml -> TOML format http://inet-ip.info

Chronometer in hour format
Shorter and faster...

Tail a log-file over the network
Netcat is used to serve a log-file over a network on port 1234. Point a browser to the specified server/port combo to view log-file updates in real-time.


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: