CODEWITHSUNDEEP
bashawk
VDC
VDC

Reputation: 1449

How to add a column from a file to another file

I have a file with two columns as

1 1
2 3
3 4

and a file with one column as

6
7
9

I would like to add the second file in the first one. The output should be:

1 1 6
2 3 7
3 4 9

Upvotes: 34

Views: 75422

Answers (3)

TrueY
TrueY

Reputation: 7610

A pure solution can be:

echo -e "1 1\n2 3\n3 4" >onefile
echo -e "6\n7\n9" >twofile

exec 3<twofile
while read x; do read -u 3 y; echo $x $y; done <onefile
# exec 3<&- # Close the file, if not needed

or on a more general way:

exec {fd}<twofile
while read x; do read -u $fd y; echo $x $y; done <onefile
# exec $fd<&- # Close the file, if not needed

Output:

1 1 6
2 3 7
3 4 9

Upvotes: 3

jaypal singh
jaypal singh

Reputation: 77105

awk 'NR==FNR{a[NR]=$0;next}{print a[FNR],$0}' file1 file2

Note: Will work with files of same length. If file lengths' are different, go with sudo_O's solution.

Just for the heck of it, here is an awk command that I think should simulate paste. Purely for fun though, if I were you I would still go with sudo_O's solution (or may be not!)

awk 'NR==FNR{a[++y]=$0;next}{b[++x]=$0}
END{z=x>y?x:y;while(++i<=z){print a[i],b[i]}}' file1 file2

Upvotes: 12

Chris Seymour
Chris Seymour

Reputation: 85795

$ pr -mts' ' file1 file2
1 1 6
2 3 7
3 4 9

$ paste -d' ' file1 file2
1 1 6
2 3 7
3 4 9

Upvotes: 50

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