Re^5: An overlapping regex capture

No, you got the error saying that $filename.fa is uninitialized.

So perl saw that as a variable name while you intended to only use $filename instead.

In order to delimit the variable name you can use this syntax: "${filename}.fa".

Good luck, hexcoder

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Re^6: An overlapping regex capture by haukex (Archbishop) on Jun 22, 2017 at 12:40 UTC
No, you got the error saying that $filename.fa is uninitialized. So perl saw that as a variable name ... Sorry, but that's not correct in this case, a dot does end the variable name being interpolated. As the OP is using strict, that would have caught the error anyway. Your advice does apply for other characters though. `$ perl -wMstrict -le 'my $fn="x"; print "$fn.y"' x.y $ perl -wMstrict -le 'my $fn="x"; print "$fn_y"' Global symbol "$fn_y" requires explicit package name (did you forget t +o declare "my $fn_y"?) at -e line 1. Execution of -e aborted due to compilation errors. $ perl -w -le 'my $fn="x"; print "$fn_y"' Name "main::fn_y" used only once: possible typo at -e line 1. Use of uninitialized value $fn_y in string at -e line 1. $ perl -wMstrict -le 'my $fn="x"; print "${fn}_y"' x_y` [download]	[reply] [d/l]

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Re^6: An overlapping regex capture
by haukex (Archbishop) on Jun 22, 2017 at 12:40 UTC

No, you got the error saying that $filename.fa is uninitialized. So perl saw that as a variable name ...

Sorry, but that's not correct in this case, a dot does end the variable name being interpolated. As the OP is using strict, that would have caught the error anyway. Your advice does apply for other characters though.

$ perl -wMstrict -le 'my $fn="x"; print "$fn.y"'
x.y
$ perl -wMstrict -le 'my $fn="x"; print "$fn_y"'
Global symbol "$fn_y" requires explicit package name (did you forget t
+o declare "my $fn_y"?) at -e line 1.
Execution of -e aborted due to compilation errors.
$ perl -w        -le 'my $fn="x"; print "$fn_y"'
Name "main::fn_y" used only once: possible typo at -e line 1.
Use of uninitialized value $fn_y in string at -e line 1.
$ perl -wMstrict -le 'my $fn="x"; print "${fn}_y"'
x_y
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