Commands by pholz (2)

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

Go to parent directory of filename edited in last command
Uses the last argument of the last executed command, and gets the directory name from it. Use $!:t for the filename alone, without the dirname.

Count Files in a Directory with Wildcards.
Remove the '-maxdepth 1' option if you want to count in directories as well

check open ports without netstat or lsof

Display all shell functions set in the current shell environment
Uses the shell builtin `declare` with the '-f' flag to output only functions to grep out only the function names. You can use it as an alias or function like so: alias shfunctions="builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ \(\)'" shfunctions () { builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ \(\)'; }

find unreadable file

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Runs previous command but replacing
Replaces the first instance of 'foo' with 'bar'. To replace all instances of 'foo' with 'bar': !!:gs/foo/bar/

Watch the progress of 'dd'
This version was mentioned in the comments. Credits go to flatcap.

Count the total amount of hours of your music collection
First the find command finds all files in your current directory (.). This is piped to xargs to be able to run the next shell pipeline in parallel. The xargs -P argument specifies how many processes you want to run in parallel, you can set this higher than your core count as the duration reading is mainly IO bound. The -print0 and -0 arguments of find and xargs respectively are used to easily handle files with spaces or other special characters. A subshell is executed by xargs to have a shell pipeline for each file that is found by find. This pipeline extracts the duration and converts it to a format easily parsed by awk. ffmpeg reads the file and prints a lot of information about it, grep extracts the duration line. cut and sed cut out the time information, and tr converts the last . to a : to make it easier to split by awk. awk is a specialized programming language for use in shell scripts. Here we use it to split the time elements in 4 variables and add them up.


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