Bash

Find the location of a script, no matter how it's referenced when run

DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )" 
echo $DIR

Convert files/text to hex and back

I had a weird looking filename in a backup and found the following while trying to figure out what the character might be.

[user@host photos]$ ls | xxd -g1
0000000: ef 80 a3 33 2e 70 6e 67 0a                       ...3.png.
[user@host photos]$ xxd -g1 -r
0000000: ef 80 a3 33 2e 70 6e 67 0a                       ...3.png.
3.png

xxd is part of vim-common on CentOS and it's better than od because -r will reverse the hex dump and convert it to a binary file!

replace file extensions without sed

for i in *.sh; do echo "${i%.sh}.bat"; done