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Convert all JPEG images to MP4
Source: http://superuser.com/a/624574

Indent a one-liner.
Bash builtin type also indents the function.

Extract audio from start to end position from a video
mplayer -vc null -vo null -ao pcm Firefly\ ep\ 10.avi -ss 195 -endpos 246 Will create file audiodump.wav with audio from second 195 to second 246 (the opnening theme).

Efficient count files in directory (no recursion)
$ time perl -e 'if(opendir D,"."){@a=readdir D;print $#a - 1,"\n"}' 205413 real 0m0.497s user 0m0.220s sys 0m0.268s $ time { ls |wc -l; } 205413 real 0m3.776s user 0m3.340s sys 0m0.424s ********* ** EDIT: turns out this perl liner is mostly masturbation. this is slightly faster: $ find . -maxdepth 1 | wc -l sh-3.2$ time { find . -maxdepth 1|wc -l; } 205414 real 0m0.456s user 0m0.116s sys 0m0.328s ** EDIT: now a slightly faster perl version $ perl -e 'if(opendir D,"."){++$c foreach readdir D}print $c-1,"\n"' sh-3.2$ time perl -e 'if(opendir D,"."){++$c foreach readdir D}print $c-1,"\n"' 205414 real 0m0.415s user 0m0.176s sys 0m0.232s

benchmark web server with apache benchmarking tool
-n 9000 : Number of requests to perform for the benchmarking session -c 900 : Number of multiple requests to perform at a time

Continuously listen on a port and respond with a fixed message with netcat (and respond to kill signals)
`while true`: do forever `nc -l -p 4300 -c 'echo hello'`: this is the but anything can go here really `test $? -gt 0 && break`: this checks the return code for ctrl^c or the like and quite the loop, otherwise in order to kill the loop you'd have to get the parent process id and kill it.

Find installed network devices
Find installed network devices.

Find directory depth
Returns a the directory depth.

Short one line while loop that outputs parameterized content from one file to another
The above is an example of grabbing only the first column. You can define the start and end points specifically by chacater position using the following command: $ while read l; do echo ${l:10:40}; done < three-column-list.txt > column-c10-c40.txt Of course, it doesn't have to be a column, or extraction, it can be replacement $ while read l; do echo ${l/foo/bar}; done < list-with-foo.txt > list-with-bar.txt Read more about parameter expansion here: http://wiki.bash-hackers.org/syntax/pe Think of this as an alternative to awk or sed for file operations

Sort content of a directory including hidden files.
This command sorts the content including hidden files in human readable format of the current directory.


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