Data manipulation using Perl script

Question

Input:

Col1 col2 col3 col4
aaa   15   23   A
bbb    7    5   B
ccc   43   10   C

Expected output

aaa  15  16
bbb   7   8
ccc  43  44

I know to get this using awk but I need to do this in Perl. I tried using an array in Perl like

 push(@output_array, $temp_array[0] . "\t" . $temp_array[1] .  "\n");

I don't know how to add 1 to the col2 and make it as col3. Can anybody help me out?

There's a program that's been distributed with Perl since forever called a2p for converting awk scripts to Perl. (There's also an s2p for converting sed scripts to Perl.) Maybe that would help? — Jonathan Leffler
– Jonathan Leffler, Commented May 12, 2014 at 4:17

Miller · Accepted Answer · 2014-05-12 04:20:46Z

4

In a perl oneliner

perl -lane 'print join("\t", @F[0,1], $F[1] + 1)' file.txt

If you want to truncate a header row:

perl -lane 'print join("\t", @F[0,1], $. == 1 ? $F[2] : $F[1] + 1)' file.txt

If you want to completely remove a header row:

perl -lane 'print join("\t", @F[0,1], $F[1] + 1) if $. > 1' file.txt

edited May 12, 2014 at 4:20

answered May 12, 2014 at 3:57

Miller

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5 Comments

sara Over a year ago

can you help me on how to do that using array?

salparadise Over a year ago

@F its an array. Gets invoked by using the "-a" command line switch. perldoc perlrun

sara Over a year ago

@Miller, the second one liner is not removing the header

Jonathan Leffler Over a year ago

@sara: it isn't trying to remove the header; it is echoing it with the heading of column 3 unchanged. If you don't want the first line printed, then add if $. > 1 between the close parenthesis and single quote of the first script.

Miller Over a year ago

@sara Added 3rd option for completely removing a header row instead of just truncating.

sara · Accepted Answer · 2014-05-12 05:28:50Z

0

push(@output_array, $temp_array[0] . "\t" , $temp_array[1] . "\t" , $temp_array[1] + 1 . "\n");

answered May 12, 2014 at 5:28

sara

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