Grep the number of occurences in a file, counting multiple hits per line

When you need to bulk rename files you can not call "mv *.foo *.bar" to change the extension of all .foo files to bar (because bash resolves wildcards and replaces them with the list of matched files).

This works on linuxes who use the ...

The tree command will show you the contents of a directory and all its sub directories as a tree:

>tree
.
├── a
│   ├── file_1.txt
│   └── file_2.txt
└── b
    ├── c
    │   └── even_more.txt
    └── more.txt

3 directories, 4 files

If...

$RANDOM on bash returns a random integer between 0 and 32767.

echo $RANDOM
9816
echo $RANDOM
30922

If you want to limit that to a certain maximum, you can just compare against the modulus of that maximum + 1. \
For example, the fo...

When you drag a file from a Nautilus window into a terminal window, the file's path will be pasted into the terminal. This also works with multiple files.

Call geordi clean from a project root to remove unused and unnecessary files inside it.

This script is part of our geordi gem on github. In Geordi > 1.2 you can call geordi clean.

From the shell:

ls -l | wc -l

If you want to manually check if e-mail delivery works on a machine by sending an e-mail you can run the following:
mail -s Test someone@example.com < /dev/null

This will send an empty e-mail with "Test" as its subject to `someone@example.com...

When you do a bitwise copy using the dd tool you will not see any output until it completes or an error occurs.
However, you can send a command signal to the process to have it show its progress so far.

From another terminal, simply call (be ro...

This can be helpful when you need the latest file inside a directory for processing in a shell script:

ls -1tr * | tail -1

Used switches

The -1 switch makes ls return 1 file per line, -t orders by modification time and...