1.1 KiB
1.1 KiB
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| Useful Commands |
[toc]
Imagemagick
Splitting PDF files
$ convert -density 600 (input.pdf) -crop 50x100% +repage (out.pdf)
-density: adjusts the quality of the resulting pdf. Higher values look better, but take longer to process
-crop 50x100%: this splits the pdf into "left" and "right". 100x50% would split into "top" and "bottom"
Find
Change filtered permissions
Using find with its exec switch one can set different permissions based on the usual find filters.
One example would be only changing file or directory permissions.
$ find (directory) -type f -exec chmod 744 {} +
Replacing -type f with -type d would execute the chmod for directories instead.
Various
Overwrite disk with pseudorandom data
Using openssl on CPUs with AES acceleration one can create pseudorandom data with high speeds.
Much faster than /dev/urandom at least
# openssl enc -aes-128-ctr -md sha512 -pbkdf2 -nosalt -pass file:/dev/urandom < /dev/zero | pv > (target disk)
Around 2GiB/s on my Ryzen 7 1700x if output to /dev/null