SHELL

bash remove first character

# removes the FIRST character
cut -c2-
# removes the FIRST 5 characters
cut -c6-
# removes the LAST 3 characters
rev | cut -c4- | rev
# returns the charcaters INBETWEEN the 2. and 4. character
cut -c2-4

bash remove first line

tail -n +2 "$FILE"