Insert newline before first line

Question

I am trying to insert a newline before the first line of text in a file. The only solution i have found so far is this:

sed -e '1 i
')

I do not like to have an actual newline in my shell script. Can this be solved any other way using the standard (GNU) UNIX utilities?

Answer 1

Here's a pure sed solution with no specific shell requirements:

sed -e '1 s|^|\n|'

EDIT:

Please note that there has to be at least one line of input for this (and anything else using a line address) to work.

Answer 2

对于品种：

echo | cat - file

Answer 3

单引号字符串前的$将导致bash解释其中的转义序列。

sed -e '1 i'$'\n'

Answer 4

You could use awk:

$ awk 'FNR==1{print ""} 1' file

Which will work with any number of files.