Commands by dadi (1)

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Calculate N!

Get the size of all the directories in current directory (Sorted Human Readable)
This allows the output to be sorted from largest to smallest in human readable format.

Help shell find freshly installed applications (re: PATH)
Immediately after installing things into your PATH (e.g. under /usr/bin), currently open shells cannot find them ("zsh: command not found"). Use rehash to get the shell to rescan available executables.

floating point operations in shell scripts
Calculator for shell. Similar performance and basic usage as 'bc', but with more advanced features. Not installed on most systems by default.

Generate random password on Mac OS X
Feel free to put this in your ~/.profile: $ random(){ cat /dev/urandom | env LC_CTYPE=C tr -dc $1 | head -c $2; echo; } Then use it to generate passwords: $ random [:alnum:] 16 Or DNA sequences: $ random ACGT 256

Add existing user to a group

Determine whether a CPU has 64 bit capability or not
Check if you have 64bit by looking for "lm" in cpuinfo. lm stands for "long mem". This can also be used without being root.

Convert mkv to SVCD/DivX
ffmpeg supports mkv

Count number of files in subdirectories
For each directory from the current one, list the counts of files in each of these directories. Change the -maxdepth to drill down further through directories.

Convert from octal format to umask
Umask is obtained subtracting 7 from each cypher of octal format. I store octal perm format in an array,then for each element of array I subtract 7. The result is the umask.


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