Commands by qistoph (3)

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Remove all files but one starting with a letter(s)
Remove everything in current directory except files starting with "ca".

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" }

Rename all .jpeg and .JPG files to .jpg

Parallel file downloading with wget
xargs can be used in this manner to download multiple files at a time, and xargs will in this case run 10 processes at a time and initiate a new one when the number running falls below 10.

a fast way to repeat output a byte
I'm both a one-liner fan and a haskell learner

Convert JSON to YAML (unicode safe)
If you tried the other Python version of Convert JSON to YAML and you end up with lines that has "!!python/unicode", this version of the command is for you.

Replace all tabs with spaces in an application
Note that this assumes the application is an SVN checkout and so we have to throw away all the .svn files before making the substitution.

Repeat a command until stopped
In this case it runs the command 'curl localhost:3000/site/sha' waiting the amount of time in sleep, ie: 1 second between runs, appending each run to the console. This works well for any command where the output is less than your line width This is unlike watch, because watch always clears the display.

Print number of mb of free ram
This will show the amount of physical RAM that is left unused by the system.

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.


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