Shows a file without comments (at least those starting by #) - removes empty lines - removes lines starting by # or "some spaces/tabs then #'" Useful when you want to quickly see what you have to customize on a freshly installed application without reading the comments that sometimes are a full 1000 lines documentation :) While posting, I saw this http://www.commandlinefu.com/commands/view/1041/display-contents-of-a-file-wo-any-comments-or-blank-lines But it's dirty and incomplete, to my mind My original goal was to remove lines like "\t*#" but I can't figure out how to do a egrep '\t' on a command-line. Two workarounds if needed: egrep -v 'press control + V then TAB then #' /your/file or egrep -v -f some_file /your/file #where some_file contains what you want to exclude, example a really inserted TAB

The above is just a prove of concept based around the nested bash substitution. This could be useful in situations where you're in a directory with many filetypes but you only want to convert a few. for f in *.bmp *.jpg *.tga; do convert $f ${f%.*}.png; done or you can use ls | egrep to get more specific... but be warned, files with spaces will cause a ruckus with expansion but the bash for loop uses a space delimited list. for f in $(ls | egrep "bmp$|jpg$|tga$"); do convert $f ${f%.*}.png; done I'm guessing some people will still prefer doing it the sed way but I thought the concept of this one was pretty neat. It will help me remember bash substitutions a little better :-P Show Sample Output

This is the most straightforward approach: first regexp limits dictionary file to words with thirteen or more characters, second regexp discards any words that have a letter repeated. (Bonus challenge: Try doing it in a single regexp!) Show Sample Output

In general, this is actually not better than the "scrot -d4" command I'm listing it as an alternative to, so please don't vote it down for that. I'm adding this command because xwd (X window dumper) comes with X11, so it is already installed on your machine, whereas scrot probably is not. I've found xwd handy on boxen that I don't want to (or am not allowed to) install packages on. NOTE: The dd junk for renaming the file is completely optional. I just did that for fun and because it's interesting that xwd embeds the window title in its metadata. I probably should have just parsed the output from file(1) instead of cutting it out with dd(1), but this was more fun and less error prone. NOTE2: Many programs don't know what to do with an xwd format image file. You can convert it to something normal using NetPBM's xwdtopnm(1) or ImageMagick's convert(1). For example, this would work: "xwd | convert fd:0 foo.jpg". Of course, if you have ImageMagick already installed, you'd probably use import(1) instead of xwd. NOTE3: Xwd files can be viewed using the X Window UnDumper: "xwud <foo.xwd". ImageMagick and The GIMP can also read .xwd files. Strangely, eog(1) cannot. NOTE4: The sleep is not strictly necessary, I put it in there so that one has time to raise the window above any others before clicking on it. Show Sample Output

Does not print any line that either: - is empty - contains only spaces or tabs - starts with # - starts with spaces/tabs followed by a #

Needed to get the Mac of various devices on a solaris box, but didn't have root. This command used awk to display the Network device, the IP, and the MAC a line at a time.

Is the better option on a Open SuSE Box

I created this command to give me a quick overview of how many file types a directory, and all its subdirectories, contains. It works based off file extension, rather than file(1)'s magic output, because it ended up being more accurate and less confusing. Files that don't have an ext (README) are generally not important for me to want to count, but you're free to customize this fit your needs. Show Sample Output

If you have lots of subversion working copies in one directory and want to see in which repositories they are stored, this will do the trick. Can be convenient if you need to move to a new subversion server. Show Sample Output

Where COMMAND is the process(es) name. I prefer to get all states but you may add ESTABLISHED in the grep regex. lsof -c apache2 | egrep -o 'TCP.*ESTABLISHED.*$' -nP flags are optional and UDP is irrelevant for established connections Similar but using the process id: lsof -nP -p PID | egrep -o '(TCP|UDP).*$' Show Sample Output

Rename all mp4 files with crc32 information. Show Sample Output

Depending on your Apache access log configuration you may have to change the sum+=$11 to previous or next awk token. Beware, usually in access log last token is time of response in microseconds, penultimate token is size of response in bytes. You may use this command line to calculate sum and average of responses sizes. You can also refine the egrep regexp to match specific HTTP requests. Show Sample Output

A grep against ethtool to look for common errors and packet loss statistics which network drivers report in their private data, which is queried with ethool -S. This is the current grep used in xsos (https://github.com/ryran/xsos), which I originally contributed and has been improved by the community over time. Show Sample Output

Its possible to user a simple regex to extract de username from the finger command. The final echo its optional, just for remove the initial space Show Sample Output

Using egrep to search multiple patterns. Show Sample Output