commandlinefu.com is the place to record those command-line gems that you return to again and again.
Delete that bloated snippets file you've been using and share your personal repository with the world. 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.
If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/
You can sign-in using OpenID credentials, or register a traditional username and password.
First-time OpenID users will be automatically assigned a username which can be changed after signing in.
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
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:
This function defines a command line calculator that handles everything pythons math module can handle, e.g. trigonometric functions, sqrt, log, erf, ... (see http://docs.python.org/library/math.html). It even knows about the constants pi and e.
You have a python script that slowly prints output, you want to pipe the output to grep or tee, and you are impatient and want to watch the results right away. Rather than modify your script (making it slightly less efficient), use the -u option to have the output unbuffered.
Will handle pretty much all types of CSV Files.
The ^M character is typed on the command line using Ctrl-V Ctrl-M and can be replaced with any character that does not appear inside the CSV.
Tips for simpler CSV files:
* If newlines are not placed within a csv cell then you can replace `map(repr, r)` with r
Just a small hack for ruby's environment.rb
on multihomed hosts, connected to several networks, could be usefull to know the source address (local ip address) used to reach the target host, this command does not require root priviledges.
The command use a TCP socket, if there is any error the command return an empty string, elsewhere return a valid ip address.
You need python-scapy package
You can use a site like http://www.jsonlint.com/ or use the command line to validate your long and complex json data. This is part of the simplejson package for python http://undefined.org/python/#simplejson.
Wrong json expression example:
echo '{ 1.2:3.4}' | python -m simplejson.tool
Expecting property name: line 1 column 2 (char 2)
The socket.gethostname() call returns the host name of the computer. The socket.gethostbyname_ex() call returns a list of three items: The host name, the list of aliases for this host, and a list of IP addresses. Recall that Python?s array starts with index 0, the socket.gethostbyname_ex(?)[2] expression refers to the list of IP addresses. Finally, the print statement prints out the IP addresses, one per line.
One can test their python regex matching using this shell function.
for e.g.
rgx_match "translate\s*\(([0-9-.]+),([0-9-.]+)\)" "translate(162.11517,76.817357)"
('162.11517', '76.817357')
srchpymod
for e.g.
srchpymod cairo Surface
['ImageSurface', 'PDFSurface', 'PSSurface', 'SVGSurface', 'Surface', 'SurfacePattern', 'XlibSurface']