Ordering and creating an Unix file

I have an data file in Unix which contains the following records:

1

2

3

4

5

6

I will pass a parameter based on which a new file should be created. For example, it the parameter value is 2, the new file will be:

1 2

3 4

5 6

Similarly, if the parm is 3, then:

1 2 3

4 5 6

Can s开发者_Python百科omeone give me some hints on how to do this?

Thanks, Visakh

You can use this perl one-liner:

perl -e "map chomp, @a=<>; print join(' ', splice @a,0,2).$/ while @a;" <(seq 6)
# 1 2
# 3 4
# 5 6

perl -e "map chomp, @a=<>; print join(' ', splice @a,0,3).$/ while @a;" <(seq 6)
# 1 2 3
# 4 5 6

This you can easily incorporate into a shell script:

n=3
perl -e "map chomp, @a=<>; print join(' ', splice @a,0,$n).$/ while @a;" <file>

#!/usr/bin/perl -w

# formatter.pl

use strict;
use warnings;

my $newlineCnt = $ARGV[1];
if (! defined $newlineCnt) { $newlineCnt = 1; }

my $idx = 0;
while (<>) {
    if ($idx == $newlineCnt) { print "\n"; $idx = 0; }
    $idx++;
    print "$_ ";
}

On the command line, leaving out the parameter defaults to 1:

$ formatter.pl < testData.txt
1
2
3
4
5
6

On the command line, specifying 2 as the test parameter:

$ formatter.pl 2 < testData.txt
1 2
3 4
5 6