Commands by PeekNPoke (0)

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What's this? 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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Perl Simple Webserver
First we accept a socket and fork the server. Then we overload the new socket as a code ref. This code ref takes one argument, another code ref, which is used as a callback. The callback is called once for every line read on the socket. The line is put into $_ and the socket itself is passed in to the callback. Our callback is scanning the line in $_ for an HTTP GET request. If one is found it parses the file name into $1. Then we use $1 to create an new IO::All file object... with a twist. If the file is executable("-x"), then we create a piped command as our IO::All object. This somewhat approximates CGI support. Whatever the resulting object is, we direct the contents back at our socket which is in $_[0].

Last month
Work out last months value

Perl Command Line Interpreter
Can also just use the debug mode like this.

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

dd with progress bar and statistics
Will automatically take the size of the file but longer, usefull only if in an function.

Create an audio test CD of sine waves from 1 to 99 Hz
This command creates and burns a gapless audio CD with 99 tracks. Each track is a 30 second sine wave, the first is 1 Hz, the second 2 Hz, and so on, up to 99 Hz. This is useful for testing audio systems (how low can your bass go?) and for creating the constant vibrations needed to make non-Newtonian fluids (like cornstarch and water) crawl around. Note, this temporarily creates 500MB of .cdda files in the current directory. If you don't use the "rm" at the end of the command, you can burn more disks using $ cdrdao write cdrdao.toc Prerequisites: a blank CD-R in /dev/cdrw, sox (, and cdrdao ( I'm also assuming a recent version of bash for the brace expansion (which just looks nicer than using seq(1), but isn't necessary).

Count number of files in subdirectories
For each directory from the current one, list the counts of files in each of these directories. Change the -maxdepth to drill down further through directories.

Create colorized html file from Vim or Vimdiff
While editing a source file in vim, or using vimdiff to compare two or more files, the ':TOhtml' command can be used to export each buffer as an html file, including syntax highlighting and vimdiff colorization. If you are in insert mode in vim, you will have to type :TOhtml This will open a new buffer filled with html, which you can then save.

List apache2 virtualhosts
Lists virtualhosts currently enabled for apache2, showing the ServerName:port, conf file and DocumentRoot

Print one . instead of each line
this version only uses shell builtins

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