Suggested One liners

[Utsav Barman]

du -ah / 2>/dev/null | sort -hr | less

du is in the GNU coreutils, so it’s installed on most distros. It returns a list of all directories in the specified directory (/ in this case) with their disk usage, tallied up at the end as well.

-a makes it return files as well.

-h makes it return in human readable format (7.2G instead of 7200000000).

sort -hr sorts it based on size (-human readable and -reversed)

less lets you scroll through the output.

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-r and -I options for grep searches recursively in the path you give it and ignores binary files, respectively:

$ grep -inrI 'some text' /path/to/dir
/path/to/dir/file1:10: this has some text on line 10
/path/to/dir/other_file:2: list of awesome textiles:
/path/to/dir/subdir/.hidden_file:537: sOme TExt ThaT is HidDEn
In bash, using $(< /path/to/file) instead of $(cat /path/to/file) when you want the contents of a file as a variable. The first form is faster according to bash(1).

Also in bash, arithmetic expansion using $((...)):

$ var1=1
$ var2=2
$ echo $((var1 + var2))
3
Slight nitpick, my understanding is that $(command) syntax is preferred over command syntax these day. It flows better with the rest of the language. Plus you can nest them nicely with $(command1 $(command2)).