Re: Sorting a File which contains numbers

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Re^2: Sorting a File which contains numbers by johngg (Canon) on Oct 30, 2006 at 14:50 UTC
Your solution is going to fail as soon as you encounter numbers that are more than single-digits because the default sort that you use is lexical, not numeric. Consider `perl -le '@arr = (2, 17, 8, 5, 26); print for sort @arr;'` [download] produces `17 2 26 5 8` [download] whereas `perl -le '@arr = (2, 17, 8, 5, 26); print for sort {$a <=> $b} @arr;'` [download] does a numerical sort and produces `2 5 8 17 26` [download] To sort descending numerically change the anonymous `sort` routine to `{$b <=> $a}` rather than using `reverse`. Cheers, JohnGG	[reply] [d/l] [select]

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perl -le '@arr = (2, 17, 8, 5, 26);
print for sort @arr;'
[download]

produces

17
2
26
5
8
[download]

whereas

perl -le '@arr = (2, 17, 8, 5, 26);
print for sort {$a <=> $b} @arr;'
[download]

does a numerical sort and produces

2
5
8
17
26
[download]

To sort descending numerically change the anonymous sort routine to {$b <=> $a} rather than using reverse.

Cheers,

JohnGG