String Substitution question

[LtCommander]

This could be a stupid question but I am really stuck!

I am doing
$content=~ s/$m//sig;

The problem is that $m may have all sorts of escape sequence
characters, brackets and so on. So, sometimes, $content doesn't have
$match removed. So, I do this:

$m =~ s/\(/\\(/sig;
$m =~ s/\)/\\)/sig;
$m =~ s/\[/\\[/sig;
$m =~ s/\]/\\]/sig;
$m =~ s/\?/\\?/sig;
$m =~ s/\*/\\*/sig;
$m =~ s/\./\\./sig;
$m =~ s/\$/\\\$/sig;
$m =~ s/\+/\\+/sig;
$m =~ s/\_/\\_/sig;
$m =~ s/\-/\\-/sig;
and then
$content=~ s/$m//sig;

Is there a better way of doing this?

Thanks a lot for any help.

VInce

 

[Mirco Wahab]

I am doing
$content=~ s/$m//sig;

The problem is that $m may have all sorts of escape sequence
characters, brackets and so on. So, sometimes, $content doesn't have
$match removed. So, I do this:

$m =~ s/\(/\\(/sig;
...
$m =~ s/\-/\\-/sig;
and then
$content=~ s/$m//sig;

try:

my @stuff = qw'( ) [ ] ? * . $ + _ -';
my $m = join '|', map "\Q$_\E", @stuff;

$content =~ s/$m//g;


maybe it does what you want ...

Regards

M.

 

[Mirco Wahab]

I am doing
$content=~ s/$m//sig;

The problem is that $m may have all sorts of escape sequence
characters, brackets and so on. So, sometimes, $content doesn't have
$match removed. So, I do this:

$m =~ s/\(/\\(/sig;
...
$m =~ s/\-/\\-/sig;
and then
$content=~ s/$m//sig;

try:

my @stuff = qw'( ) [ ] ? * . $ + _ -';
my $m = join '|', map "\Q$_\E", @stuff;

$content =~ s/$m//g;

the above looks somehow inefficient after a moment - ,
so better try (Perl's '|' alternation is slow)

my @stuff = qw'( ) [ ] ? * . $ + _ -';
my $m = '[' . (join '', map quotemeta, @stuff) . ']';

$content =~ s/$m//g;


Regards

M.

 

[Paul Lalli]

This could be a stupid question but I am really stuck!

I am doing
$content=~ s/$m//sig;

The problem is that $m may have all sorts of escape sequence
characters, brackets and so on. So, sometimes, $content doesn't have
$match removed. So, I do this:

$m =~ s/\(/\\(/sig;
$m =~ s/\)/\\)/sig;
$m =~ s/\[/\\[/sig;
$m =~ s/\]/\\]/sig;
$m =~ s/\?/\\?/sig;
$m =~ s/\*/\\*/sig;
$m =~ s/\./\\./sig;
$m =~ s/\$/\\\$/sig;
$m =~ s/\+/\\+/sig;
$m =~ s/\_/\\_/sig;
$m =~ s/\-/\\-/sig;
and then
$content=~ s/$m//sig;

Is there a better way of doing this?

Dear god yes.

Just do:
$content =~ s/\Q$m\E//sig;

Look up what that does in:
perldoc -f quotemeta
perldoc perlre

Paul Lalli

 

[Tad McClellan]

$m =~ s/\(/\\(/sig;
$m =~ s/\)/\\)/sig;
$m =~ s/\[/\\[/sig;
$m =~ s/\]/\\]/sig;
$m =~ s/\?/\\?/sig;
$m =~ s/\*/\\*/sig;
$m =~ s/\./\\./sig;
$m =~ s/\$/\\\$/sig;
$m =~ s/\+/\\+/sig;
$m =~ s/\_/\\_/sig;
$m =~ s/\-/\\-/sig;

OH! I see it, it's a pony!

Bzzzt! It's a camel.

With two humps.

 

[Guest]

This could be a stupid question but I am really stuck!

I am doing
$content=~ s/$m//sig;

The problem is that $m may have all sorts of escape sequence
characters, brackets and so on. So, sometimes, $content doesn't have
$match removed. So, I do this:

$m =~ s/\(/\\(/sig;
$m =~ s/\)/\\)/sig;
$m =~ s/\[/\\[/sig;
$m =~ s/\]/\\]/sig;
$m =~ s/\?/\\?/sig;
$m =~ s/\*/\\*/sig;
$m =~ s/\./\\./sig;
$m =~ s/\$/\\\$/sig;
$m =~ s/\+/\\+/sig;
$m =~ s/\_/\\_/sig;
$m =~ s/\-/\\-/sig;
and then
$content=~ s/$m//sig;

Is there a better way of doing this?

Thanks a lot for any help.

VInce

Yes:

$content =~ s/\Q$m\E//ig;

Read the docs:
perldoc perlre
perldoc -f quotemeta

 

[Dr.Ruud]

Mirco Wahab schreef:

my @stuff = qw'( ) [ ] ? * . $ + _ -';
my $m = '[' . (join '', map quotemeta, @stuff) . ']';

Alternatives:

my $m = q:[: . quotemeta( q)[]?*.$+_-: ) . q:]: ;


$ perl -wle'
my $m = q:][()?*.$+_-: ;
print qr/[$m]/
'
(?-xism:[][()?*.$+_-])

 

[Mirco Wahab]

Alternatives:
my $m = q:[: . quotemeta( q)[]?*.$+_-: ) . q:]: ;

Of course, dropping the @stuff makes things smaller ;-)

$ perl -wle'
my $m = q:][()?*.$+_-: ;
print qr/[$m]/
'
(?-xism:[][()?*.$+_-])

OK, but wouldn't this throw an 'unmatched ] bracket'
or something when used on strings with '] ['

No, it doesn't. I did *not* expect this would work:

my $content = '
Hello ( zszs ) hs $ jjs + owow - kshs ? hhshs [ tetet [] hshs!
';

my $m = '][()?*.$+_-';
$content =~ s/[$m]//g;
print $content;


.... and still roll my eyes!

Thanks for clearing this up,

M.

 

[LtCommander]

Thank you all for replying. This seems very basic yet I guess you miss
some things when you are self-taught.
Also, thanks for the pony + camel humor!!

Vince

This could be a stupid question but I am really stuck!

I am doing
$content=~ s/$m//sig;

The problem is that $m may have all sorts of escape sequence
characters, brackets and so on. So, sometimes, $content doesn't have
$match removed. So, I do this:

$m =~ s/\(/\\(/sig;
$m =~ s/\)/\\)/sig;
$m =~ s/\[/\\[/sig;
$m =~ s/\]/\\]/sig;
$m =~ s/\?/\\?/sig;
$m =~ s/\*/\\*/sig;
$m =~ s/\./\\./sig;
$m =~ s/\$/\\\$/sig;
$m =~ s/\+/\\+/sig;
$m =~ s/\_/\\_/sig;
$m =~ s/\-/\\-/sig;
and then
$content=~ s/$m//sig;

Is there a better way of doing this?

Thanks a lot for any help.

VInceYes:

$content =~ s/\Q$m\E//ig;

Read the docs:
perldoc perlre
perldoc -f quotemeta