# Created on savesnippets.com · https://savesnippets.com/3JRsfhKaoaxrje
s="hello-world-foo-bar"

# Substring (offset, length)
echo "${s:6}"            # world-foo-bar
echo "${s:6:5}"          # world

# Find & replace
echo "${s/-/_}"          # hello_world-foo-bar  (first occurrence)
echo "${s//-/_}"         # hello_world_foo_bar  (all occurrences)
echo "${s/#hello/HI}"    # HI-world-foo-bar      (only if prefix)
echo "${s/%bar/BAZ}"     # hello-world-foo-BAZ   (only if suffix)

# Strip prefix / suffix
file="path/to/config.json"
echo "${file##*/}"       # config.json    (everything after last /)
echo "${file%/*}"        # path/to        (everything before last /)
echo "${file##*.}"       # json           (extension)
echo "${file%.*}"        # path/to/config (sans extension)