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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.

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Sort movies by length, longest first
Sort .avi movies by time length, print the longest first, and so on...

Test your bash skills.

Are the two lines anagrams?
This is just a slight alternative that wraps all of #7917 in a function that can be executed

Filter the output of a file continously using tail and grep
The OPs solution will work, however on some systems (bsd), grep will not filter the data, unless the --line-buffered option is enabled.

Optimal way of deleting huge numbers of files
Using xargs is better than: $ find /path/to/dir -type f -exec rm \-f {} \; as the -exec switch uses a separate process for each remove. xargs splits the streamed files into more managable subsets so less processes are required.

A one-line web server in Ruby
Here's how to serve a directory in one line of Ruby. Handy for sharing files at a conference, for example.

Route outbound SMTP connections through a addtional IP address rather than your primary

Generic shell function for modifying files in-place
Some commands (such as sed and perl) have options to support in-place editing of files, but many commands do not. This shell function enables any command to change files in place. See the sample output for many examples. The function uses plain sh syntax and works with any POSIX shell or derivative, including zsh and bash.

Format partition with ext4 but without a journal
For slow flash memory (cheap thumb drive), ext4 is the fastest stable file system for all use cases with no relevant exception: http://www.linuxplanet.com/linuxplanet/tutorials/7208/1 Since we can usually dispense with the benefits of a journal for this type of storage, this is a way to achieve the least awful I/O-speed. Disabling the journal for an existing ext4 partition can be achieved using $ tune2fs -O ^has_journal /dev/sdXN Note that it is often recommended to format removable flash media with ext2, due to the lack of a journal. ext4 has many advantages over ext2 even without the journal, with much better speed as one of the consequences. So the only usecase for ext2 would be compatibility with very old software.

Run command in an ftp session
By putting ! in front of a command, we are able to run it from an ftp session.


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