repeat string in a line using sed

I w开发者_开发知识库ould like to repeat each line's content of a file, any quick solution using sed.

supposed the input file is

abc

def

123

The expected ouput is:

abcabc

defdef

123123

sed 's \(.*\) \1\1 ' infile

This might work for you:

echo -e 'aaA\nbbB\nccC' | sed 's/.*/&&/'
aaAaaA
bbBbbB
ccCccC

sed 'h;G;s/\n//' file.txt

It's even simpler if you take advantage of the variable \0, which holds the string that was matched:

sed 's/.*/\0\0/'

Try this

awk '{print $0$0}' temp.txt