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Dear Monks,
doing some exercises from the Alpaca book I noticed a strange behavior of the grep operator.
The exercise was to filter the files smaller than 1000 bytes.
This code (if called with C:\perl\bin>perl script.pl N:/TEMP/*):
#!/usr/bin/perl -l use strict; use warnings; @ARGV = map{glob} @ARGV; my @selection = grep { -s < 1000 } @ARGV; print for @selection;
produces the following error message:
Warning: Use of "-s" without parentheses is ambiguous at script.pl lin +e 7. Unterminated <> operator at script.pl line 7.
If I use the parenthesis it runs ok:
#!/usr/bin/perl -l use strict; use warnings; @ARGV = map{glob} @ARGV; my @selection = grep { (-s) < 1000 } @ARGV; print for @selection;
If I search for files bigger than 1000 the parentheses are not necessary.
It seems that perl interprets the less than sign as a part of a diamond operator.
In the answers part of the book however there is a line exact as my original line without parentheses:
my @smaller_than_1000 = grep { -s < 1000 } @ARGV;
Is it the windows peculiarity which I have here?
Thanks in advance!
VE

In reply to The "<" in the grep block by vagabonding electron

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