Commands by mrtheplague (3)

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Show permissions of current directory and all directories upwards to /
Useful if a different user cannot access some directory and you want to know which directory on the way misses the x bit.

Find broken symlinks
Locate broken symlinks in the current directory. Also useful, to remove broken links: $ find . -type l ! -exec test -e {} \; -print0 | xargs -0 rm

Basic sed usage with xargs to refactor a node.js depdendency

get all Google ipv4 subnets for a iptables firewall for example
a bit shorter, parenthesis not needed but added for clarity

Rotate a video file by 90 degrees CW

Manipulate the metadata when the photo was taken, this will shift with +15hours + 30min

Matrix Style
Solves "tr" issues with non C-locales under BSD-like systems (like OS X)

Maximum PNG compression with optipng, advpng, and advdef
optipng and advancecomp (for the the advpng and advdef tools) are the best FOSS tools for losslessly compressing PNGs. With the above tool chain, you can cut off as much as 20% off a PNG's file size.

Find files and calculate size of result in shell
Use find's internal stat to get the file size then let the shell add up the numbers.

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.


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