Commands using grep (1,935)

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Job Control
You're running a script, command, whatever.. You don't expect it to take long, now 5pm has rolled around and you're ready to go home... Wait, it's still running... You forgot to nohup it before running it... Suspend it, send it to the background, then disown it... The ouput wont go anywhere, but at least the command will still run...

Merge AVI-files without recoding
Useful for when you download movies split into < 700mb parts. Credit to rich @ http://superuser.com/questions/318640/merge-avi-files-without-recoding-in-mac-os-x-lion mencoder is generally included with mplayer. MacPorts: $sudo port install mplayer

Count the number of characters in a string from the standard input.

lines in file2 that are not in file1

Sort all running processes by their memory & CPU usage
you can also pipe it to "tail" command to show 10 most memory using processes.

Trigger a command each time a file is created in a directory (inotify)
Listens for events in the directory. Each created file is displayed on stdout. Then each fileline is read by the loop and a command is run. This can be used to force permissions in a directory, as an alternative for umask. More details: http://en.positon.org/post/A-solution-to-the-umask-problem%3A-inotify-to-force-permissions

processes per user counter
enumerates the number of processes for each user. ps BSD format is used here , for standard Unix format use : ps -eLf |awk '{$1} {++P[$1]} END {for(a in P) if (a !="UID") print a,P[a]}'

Generat a Random MAC address
Original author unknown (I believe off of a wifi hacking forum). Used in conjuction with ifconfig and cron.. can be handy (especially spoofing AP's)

Slow Down Command Output
( Or $ ls -lat|lolcat -a if you like it in technicolor - apt install lolcat if needed )

a function to find the fastest DNS server
http://public-dns.info gives a list of online dns servers. you need to change the country in url (br in this url) with your country code. this command need some time to ping all IP in list.


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