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Old 07-16-2006, 06:37 PM   #1
richikiki
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Question perl regular expression a char match


Hi guys,

I want how to validate a string line searching for any character which is not defined as:
PHP Code:
from a to z
from A to Z
from 0 to 9
. (point
- (-)
"\" (back slash) finally
[white space] 
In this case I'm looking in the whole string line give me a error message if find any char which is not in my list. I'm using this:

Code:
#!/usr/bin/perl
...
...

   if( $mystring !~ m/[a-zA-Z_0-9\.\-\\]|[ ]|/ ) # if $mystring has a non-defined char
   {
       print "Error";
   }
Does any one know what im doing wrong?
I guess my regular expressions

Regards
 
Old 07-16-2006, 11:08 PM   #2
xhi
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well it looks close.. why is there an underscore in there?

it might work like this .. maybe..
[a-zA-Z0-9\.\-\\ ]
 
Old 07-16-2006, 11:51 PM   #3
koobi
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this should work. you dont have to escape a hyphen if it's the first char
Code:
/[-a-zA-Z0-9\.\\\ ]+/
also, if there's a modifier to make it case insensitive, you can exclude either the a-z or A-Z
Code:
/[-a-z0-9\.\\\ ]+/i

if you want those chars to appear in that exact same order, the expression has to be changed but i'm not sure if that's what you want.

Last edited by koobi; 07-16-2006 at 11:53 PM.
 
Old 07-16-2006, 11:53 PM   #4
homey
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I wonder if you would might use [\w\s]+ instead.
For example:
Code:
#!/usr/bin/perl
# Example: ./myscript This is \^ test!
# Example: ./myscript There aren\'t \~ 33 Numbers \ HEre.

foreach $mystring (@ARGV) {
   if( $mystring !~ m/([\w\s]+)/ ) # if $mystring has a non-defined char
   {
       print "$mystring is not defined\n";
   }
}
 
Old 07-16-2006, 11:57 PM   #5
koobi
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Quote:
Originally Posted by homey
I wonder if you would might use [\w\s]+ instead.
For example:
Code:
#!/usr/bin/perl
# Example: ./myscript This is \^ test!
# Example: ./myscript There aren\'t \~ 33 Numbers \ HEre.

foreach $mystring (@ARGV) {
   if( $mystring !~ m/([\w\s]+)/ ) # if $mystring has a non-defined char
   {
       print "$mystring is not defined\n";
   }
}

but \w includes an underscore as well, doesn't it?
 
Old 07-17-2006, 01:32 AM   #6
richikiki
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Unhappy

Thanks guys,

but still not working

I try this:

Code:
$mystring = "!20060710,NONE,NONE,GROUP_INC,Swap,Senior Unsecured,CDS SDA,NONE,100y,0.12,0.12"
it has "!", ",". which are suppouse to not be allow on my check function. Im using this:

Code:
foreach $mystring (@ARGV)
   {
       	if( $mystring !~ m/[a-zA-Z_0-9\-\.\\ ]+/i )
         {
             print "\nError\n";
         }
   }
Nothing happen I dont know why the regular expression seems ok.
Maybe something with m/expr/option. the option are i, g, e but not sure which one is the right one, I try all them.

I'm allowing the next chars:
PHP Code:
From a to z
From A to Z
"_" [undescore]
From 0 to 9
"-" [hypen] or is this [dash]?
"." (point
"\" [back slash] and
" " [white space] 
 
Old 07-18-2006, 09:01 AM   #7
bigearsbilly
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your logic is wrong.
!~ is the NOT of =~
you are finding if NOT ANY legal chars are there.
you need a positive search for illegal chars (think about it)

Code:
          if $mystring =~ /[^-.A-Za-z0-9\s]/ ;

Last edited by bigearsbilly; 07-18-2006 at 09:03 AM.
 
Old 07-18-2006, 10:08 PM   #8
richikiki
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Lightbulb

Thanks bigearsbilly,

At the end I went to search for the chars that I dont want because my logic seems wrong.
I did the next then:

Code:
if( $mystring =~ m/[!"#\$\%&'()\*\+\,\-\/:<=>\?\@\[\\\]\^\`\{\|\}\~]+/g )# ch
ar ";" is valid after sustitution of "," for ";".
   {
        print "Error on line: $i a invalid char found aborting the parsing\n";
   }
I guess the above is different for what I was doing before, the negation of the regular expression.
All this because it could contained corrupted data which come from the excel file.Thats way I'm looking for any weird char.

I don't thing it could get control char data from the excel file isnt .
Thanks everybody for your comments.
I love this site.
 
Old 07-19-2006, 04:37 AM   #9
bigearsbilly
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Quote:
Originally Posted by richikiki
At the end I went to search for the chars that I dont want because my logic seems wrong.
I think it's generally agreed better to have a white list rather than a black list.
i.e. I think the first match is better as you never know what you've missed
with the second method.

 
  


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