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Find Out My Linux Distribution Name and Version
Another way of do it in debian like distros, don't know if works for others

Perform sed substitution on all but the last line of input
In this simple example the command will add a comma to the end of every line except the last. I found this really useful when programatically constructing sql scripts. See sample output for example.

watch process stack, sampled at 1s intervals
This command repeatedly gets the specified process' stack using pstack (which is an insanely clever and tiny wrapper for gdb) and displays it fullscreen. Since it updates every second, you rapidly get an idea of where your program is stuck or spending time. The 'tac' is used to make the output grow down, which makes it less jumpy. If the output is too big for your screen, you can always leave the 'tac' off to see the inner calls. (Or, better yet--get a bigger screen.) Caveats: Won't work with stripped binaries and probably not well with threads, but you don't want to strip your binaries or use threads anyway.

quickest (i blv) way to get the current program name minus the path (BASH)
Useful in shell scripts when you're trying to get the shell script name without the full path - and easier than awking or cutting. Bash pattern matching and variable manip is fun.

Printout a list of field numbers (awk index) from a CSV file with headers as first line.
Useful to identify the field number in big CSV files with large number of fields. The index is the reference to use in processing with commands like 'cut' or 'awk' involved.

Print the IPv4 address of a given interface

Rename files in batch

Countdown Clock
Simple countdown clock that should be quite portable across any Bourne-compatible shell. I used to teach for a living, and I would run this code when it was time for a break. Usually, I would set "MIN" to 15 for a 15-minute break. The computer would be connected to a projector, so this would be projected on screen, front and center, for all to see.

one-line log format for svn
the output of svn log is annoying to grep, since it spreads the useful info over multiple lines. This compacts the output down to one line so eg you can grep for a comment and see the rev, date & committer straight away. Updated: MUCH shorter, easier to remember. Now it just replaces newlines with spaces, except on '---' lines.

list block devices
Shows all block devices in a tree with descruptions of what they are.


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