Commands by jmorganwalker (12)

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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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How to establish a remote Gnu screen session that you can re-connect to
Long before tabbed terminals existed, people have been using Gnu screen to open many shells in a single text terminal. Combined with ssh, it gives you the ability to have many open shells with a single remote connection using the above options. If you detach with "Ctrl-a d" or if the ssh session is accidentally terminated, all processes running in your remote shells remain undisturbed, ready for you to reconnect. Other useful screen commands are "Ctrl-a c" (open new shell) and "Ctrl-a a" (alternate between shells). Read this quick reference for more screen commands: http://aperiodic.net/screen/quick_reference

grep (or anything else) many files with multiprocessor power
xargs -P N spawns up to N worker processes. -n 40 means each grep command gets up to 40 file names each on the command line.

Display full tree information of a single process

Length of longest line of code
Here's an awk version.

Find the package that installed a command

Display a block of text: multi-line grep with perl
-n reads input, line by line, in a loop sending to $_ Equivalent to while () { mycode } -e execute the following quoted string (i.e. do the following on the same line as the perl command) the elipses .. operator behaves like a range, remembering the state from line to line.

Display which distro is installed
Works on Ubuntu

Copy ssh keys to user@host to enable password-less ssh logins.
To generate the keys use the command ssh-keygen

Compare two CSV files, discarding any repeated lines
The value for the sort command's -k argument is the column in the CSV file to sort on. In this example, it sorts on the second column. You must use some form of the sort command in order for uniq to work properly.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.


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