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. Show Sample Output

checks which files are not under version control, fetches the names and runs them through "svn add". WARNING: doesn't work with white spaces.

Purge all configuration files of removed packages Show Sample Output

Finds all corrupted jpeg files in current directory and its subdirectories. Displays the error or warning found. The jpeginfo is part of the jpeginfo package in debian. Should you wish to only get corrupted filenames, use cut to extract them : find ./ -name *jpg -exec jpeginfo -c {} \; | grep -E "WARNING|ERROR" | cut -d " " -f 1 Show Sample Output

This is a command that I find myself using all the time. It works like regular grep, but returns the paragraph containing the search pattern instead of just the line. It operates on files or standard input. grepp <PATTERN> <FILE> or <SOMECOMMAND> | grepp <PATTERN> Show Sample Output

This one uses dictionary.com

Though without infinite time and knowledge of how the site will be designed in the future this may stop working, it still will serve as a simple straight forward starting point. This uses the observation that the only item marked as strong on the page is the single logical line that includes the italicized fact. If future revisions of the page show failure, or intermittent failure, one may simply alter the above to read. wget randomfunfacts.com -O - 2>/dev/null | tee lastfact | grep \<strong\> | sed "s;^.*<i>\(.*\)</i>.*$;\1;" The file lastfact, can then be examined whenever the command fails.

Trick to avoid the form: grep process | grep - v grep Show Sample Output

Put it in your ~/.bashrc usage: google word1 word2 word3... google '"this search gets quoted"' Show Sample Output

Rather than chain a string of greps together and pipe them to awk, use awk to do all the work. In the above example, a string would be output to stdout if it matched pattern1 AND pattern2, but NOT pattern3.

usefull in case of abuser/DoS attacks. Show Sample Output

The trick here is to use the brackets [ ] around any one of the characters of the grep string. This uses the fact that [?] is a character class of one letter and will be removed when parsed by the shell. This is useful when you want to parse the output of grep or use the return value in an if-statement without having its own process causing it to erroneously return TRUE. Show Sample Output

greps for search word in directory and below (defaults to cd). -i case insensitive -n shows line number -H shows file name

Highlights the search pattern in red.

This helped me find a botnet that had made into my system. Of course, this is not a foolproof or guarantied way to find all of them or even most of them. But it helped me find it.

Define a function vert () { echo $1 | grep -o '.'; } Use it to print some column headers paste <(vert several) <(vert parallel) <(vert vertical) <(vert "lines of") <(vert "text can") <(vert "be used") <(vert "for labels") <(vert "for columns") <(vert "of numbers") Show Sample Output

no loop, only one call of grep, scrollable ("less is more", more or less...)

Proper screencast with audio using ffmpeg and x264, as per http://verb3k.wordpress.com/2010/01/26/how-to-do-proper-screencasts-on-linux/

When dealing with system resource limits like max number of processes and open files per user, it can be hard to tell exactly what's happening. The /etc/security/limits.conf file defines the ceiling for the values, but not what they currently are, while ulimit -a will show you the current values for your shell, and you can set them for new logins in /etc/profile and/or ~/.bashrc with a command like: ulimit -S -n 100000 >/dev/null 2>&1 But with the variability in when those files get read (login vs any shell startup, interactive vs non-interactive) it can be difficult to know for sure what values apply to processes that are currently running, like database or app servers. Just find the PID via "ps aux | grep programname", then look at that PID's "limits" file in /proc. Then you'll know for sure what actually applies to that process. Show Sample Output

This command uses ping to get the routers' IP addresses to the destination host as traceroute does. If you know what I mean..

..not guaranteed to always be accurate but fun to see how old you Linux installation is based on the root partitions file system creation date. Show Sample Output