remove first line in bash

Question

Do you have a method to quickly remove the first line of a file in bash shell ? I mean using sed or stuff like that.

Answer 1

One-liners in reverse order of length, portable unless noted.

sed (needs GNU sed for -i):

sed -i 1d file

ed (needs e.g. bash for $'...' expansion and here string):

ed file <<< $'1d\nw\nq'

awk:

awk NR\>1 infile > outfile

tail:

tail -n +2 infile > outfile

read + cat:

(read x; cat > outfile) < infile

bash built-ins:

while IFS= read -r; do ((i++)) && printf %s\\n "$REPLY" >> outfile; done < infile

Answer 2

$ tail -n +2 <<< $'1\n2\n3'
2
3

Answer 3

Using dd

fn="The-BIG-FILE.txt"
fll=$(( $(head -n 1 $fn | wc -c) + 1))
dd if="$fn" of="${fn}.out" bs=1M iflags=skip_bytes skip=$fll
echo "Files differ by $(( $(find $fn* -printf "%s - \n" ; echo "0") )) bytes. First line of $fn is $fll bytes."

Add any iflags= and oflags= you might need - with commas separating them.