Commands by parsa (1)

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Screensaver
Console screensaver.

Count occurrences per minute in a log file
The cut should match the relevant timestamp part of the logfile, the uniq will count the number of occurrences during this time interval.

Extract multiple tar files at once in zsh
tar doesn't support wildcard for unpacking (so you can't use tar -xf *.tar) and it's shorter and simpler than for i in *.tar;do tar -xf $i;done (or even 'for i in *.tar;tar -xf $i' in case of zsh) -i says tar not to stop after first file (EOF)

sum a column of numbers

Backup a file with a date-time stamp
Appends the input file with the date format YYYY-MM-DD.bak. Also runs silently if you remove the -v on the cp at the end of the function.

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

using `!#$' to referance backward-word
expand to: cp /work/host/phone/ui/main.cpp /work/target/phone/ui/main.cpp !# The entire command line typed so far.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Search some text from all files inside a directory

Change user within ssh session retaining the current MIT cookie for X-forwarding
When you remotely log in like "ssh -X userA:host" and become a different user with "su UserB", X-forwarding will not work anymore since /home/UserB/.Xauthority does not exist. This will use UserA's information stored in .Xauthority for UserB to enable X-forwarding. Watch http://prefetch.net/blog/index.php/2008/04/05/respect-my-xauthority/ for details.


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