duplicate the line of a text file to the same line

powah · 01-11-2007, 05:05 PM

How to duplicate the line of a text file to the same line with a space inserted between them?

e.g.
input text file:
12
34
hello
/usr/xyz

output text file:
12 12
34 34
hello hello
/usr/xyz /usr/xyz

FnordPerfect · 01-11-2007, 05:15 PM

Which language? Mind if I talk bash?

Code:

#!/bin/sh

if [ ! $# -eq 2 ]; then
 echo "Syntax: $0 input_file output_file"
 exit 1
fi

if [ -f "$1" ]; then
  input_file="$1"
else
  echo "Input file \"$1\" does not exist."
  exit 2
fi

output_file="$2"

while read i
do
  echo "$i $i"
done <$input_file >$output_file

Save this in a script named to your likings, eg. insert-space.sh
then type insert-space.sh ./input_text_file.txt ./output_text_file.txt

PS: of course, this will give confusing output, if a line in the input file countains spaces...

gilead · 01-11-2007, 05:24 PM

Also using the shell (with sed) you could do the following (the data is in a file called data):

Code:

$ cat data
12
34
hello
/usr/xyz
$ sed -e 's/..*/& &/' data
12 12
34 34
hello hello
/usr/xyz /usr/xyz

jschiwal · 01-11-2007, 05:27 PM

You could use sed as well.
sed 's/.*/& &/' inputfile >outputfile

jlinkels · 01-11-2007, 08:27 PM

cat inputfile | awk '{print $0 " " $0}' > outputfile

jlinkels