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Please explain usage of m
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| Hi all:
Would you please tell me what this means:
$pstrtype = "0" unless ( $pstrtype =~ m#\S# );
My understanding: set $pstrtype to "0" if $pstrtype matches
non-whitespace character
Now, does it mean the match is true if $pstrtype
a.) contains non-whitespace characters in all positions of the string
b.) contains non-whitespace characters in first position of the string
c.) contains atleast one non-whitespace character in some position in
the string
Please help!
Thanks!
Anu M
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AM wrote:
> Hi all:
>
> Would you please tell me what this means:
> $pstrtype = "0" unless ( $pstrtype =~ m#\S# );
>
> My understanding: set $pstrtype to "0" if $pstrtype matches
> non-whitespace character
set $pstrtype to "0" UNLESS $pstrtype matches a non-whitespace
character
>
> Now, does it mean the match is true if $pstrtype
> a.) contains non-whitespace characters in all positions of the string
> b.) contains non-whitespace characters in first position of the string
> c.) contains atleast one non-whitespace character in some position in
> the string
>
> Please help!
>
> Thanks!
> Anu M
c. As there are no beginning of string (^) or end of string ($)
anchors, nor any
repitition quantifiers (+ or *). So, it matches any single
non-whitespace character.
It would appear that the value is set to '0' if the string if empty
or only contains
whitespace.
a.) contains non-whitespace characters in all positions of the string
$pstrtype = "0" unless ( $pstrtype =~ m#^\S+$# );
b.) contains non-whitespace characters in first position of the string
$pstrtype = "0" unless ( $pstrtype =~ m#^\S# );
HTH, Ken
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