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commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. 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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News

May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!
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Functions

Commands by pooderbill from sorted by
Terminal - Commands by pooderbill - 4 results
tail +### MYFILE
2015-04-23 11:49:15
User: pooderbill
Functions: tail
1

Useful for finding newly added lines to a file, tail + can be used to show only the lines starting at some offset. A syslog scanner would look at the file for the first time, then record the end_of_file record number using wc -l. Later (hours, days), scan only at the lines that were added since the last scan.

view + LOGFILE
2015-04-21 11:23:01
User: pooderbill
-1

view is the command: vi -r which opens a file in read-only mode. The + character jumps to the bottom of the logfile where the most relevant information starts. Other aliases can be created for commonly viewed logfiles.

ps -fC PROCESSNAME
2015-04-20 13:09:44
User: pooderbill
Functions: ps
Tags: grep function ps
14

ps and grep is a dangerous combination -- grep tries to match everything on each line (thus the all too common: grep -v grep hack). ps -C doesn't use grep, it uses the process table for an exact match. Thus, you'll get an accurate list with: ps -fC sh rather finding every process with sh somewhere on the line.

alias noc="awk 'NF && ! /^[[:space:]]*#/'"
2014-09-07 00:50:57
User: pooderbill
Functions: alias
1

The shortest and most complete comment/blank line remover...

Any line where the first non-whitespace character is # (ie, indented # comments), and all null and blank lines are removed. Use the alias as a filter:

noc /etc/hosts

or

grep server /etc/hosts | noc

Change to nawk depending awk versions.