Re: Reg exp questions

UPDATE: I originally misread the question... I thought the OP wanted to replace |, but the OP really wants to replace ().

\s should not be used in the REPLACEMENT part of s///

use warnings;
use strict;

my $str = 'a|b|c d    e  ';
$str =~ s/[\s|]/_/g;
print "$str\n";

$str = "w\nx\ny\nz";
$str =~ s/\n/ /g;
print "$str\n";

__END__

a_b_c_d____e__
w x y z
[download]

Here is an explanation of your 1st regex (Tip #9 from the Basic debugging checklist):

The regular expression:

(?-imsx:\s|\(|\))

matches as follows:
  
NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  \s                       whitespace (\n, \r, \t, \f, and " ")
----------------------------------------------------------------------
 |                        OR
----------------------------------------------------------------------
  \(                       '('
----------------------------------------------------------------------
 |                        OR
----------------------------------------------------------------------
  \)                       ')'
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------
[download]

Comment on Re: Reg exp questions Select or Download Code

Replies are listed 'Best First'.
Re^2: Reg exp questions by carolw (Sexton) on Nov 07, 2014 at 19:27 UTC
and if I have one space before the end of the $str and one (, one ), this doesn't work with or without / for () `$str =~ s/()[\s]/_/;` [download]	[reply] [d/l]
Re^3: Reg exp questions by toolic (Bishop) on Nov 07, 2014 at 19:31 UTC
Show your exact input strings, and your expected output strings. http://sscce.org	[reply]
Re^4: Reg exp questions by carolw (Sexton) on Nov 07, 2014 at 19:38 UTC
my $str = 'dfsldjf(djfls)jfslfk kfds\nfjsldf'; output: dfsldjf_djfls_jfslfk_kfds fjsldf	[reply]
Re^5: Reg exp questions by toolic (Bishop) on Nov 07, 2014 at 19:48 UTC
Re^6: Reg exp questions by carolw (Sexton) on Nov 07, 2014 at 20:37 UTC
Some notes below your chosen depth have not been shown here
Re^6: Reg exp questions by carolw (Sexton) on Nov 08, 2014 at 19:59 UTC
Some notes below your chosen depth have not been shown here
Re^2: Reg exp questions by carolw (Sexton) on Nov 08, 2014 at 19:33 UTC
How to combine the expressions? for ex, if I want to replace ()[] by the same char, how to can i combine it? `$str =~ s/()[]/"/g;`	[reply] [d/l]
Re^3: Reg exp questions by ww (Archbishop) on Nov 08, 2014 at 19:48 UTC
Quoting is in M$Win style: `C:\>perl -E "my $str='abc()[]xyz'; $str =~ s/[()\[\]]{1}/\"/g; say $st +r; abc""""xyz` [download] IOW, use a character class and escaping; both of which can be found in perldoc's perlre* pages. Note that the quantifier is redundant here, but could be useful were you trying to substitute two-at-a-time. OTOH, the /g modifier is NOT optional for this use case. `C:\>perl -E "my $str='a)bc([]xyz'; $str =~ s/[()\[\]]{2}/\"/g; say $st +r; a)bc"]xyz` [download] `++$anecdote ne $data`	[reply] [d/l] [select]