Delete first line of file if it's empty

Question

How can I delete the first (!) line of a text file if it\'s empty, using e.g. sed or other standard UNIX tools. I tried this command:

sed \'/^$/d\' < somefile         


        

Answer 1

The simplest thing in sed is:

sed '1{/^$/d}'

Note that this does not delete a line that contains all blanks, but only a line that contains nothing but a single newline. To get rid of blanks:

sed '1{/^ *$/d}'

and to eliminate all whitespace:

sed '1{/^[[:space:]]*$/d}'