Re^2: Tweak for my Perl Regex that screens for digits only

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Re^3: Tweak for my Perl Regex that screens for digits only by Roy Johnson (Monsignor) on Jan 25, 2006 at 18:48 UTC
You want to list all the alternatives, separated by vertical bars. For individual character alternatives, you can create a character class (a list or range of characters inside square brackets). For example: `/^(?:[-()\d\s]\|[Ee]xt\.)$/` [download] matches a series of (any combination of) only hyphen, left-paren, right-paren, digits, whitespace, or Ext. or ext. Updated: added the hyphen. Note that a hyphen, if it appears in a character class, must be the first listed character (so that it doesn't look like part of a character range). Caution:* Contents may have been coded under pressure.	[reply] [d/l]
Re^4: Tweak for my Perl Regex that screens for digits only by hackermike (Novice) on Jan 25, 2006 at 20:09 UTC
THANKS ROY! Apologies for being slow to acknowledge your reply. I goofed on first testing your code but then on inspection cleared that up and find that your regex does exactly as expected and is what I wanted, simply, and effectively, Although I would like to get the hyphen included with the permissible characters, and wonder whether it will require the escape backslash? Thank you for your very kind condsideration of this hapless hacker! Mike I WROTE: I have this regex in my simple perl script handling a html form: `unless ($FORM{'phone'} =~ /\s$$\.\d+\-\s/) {` [download] ... the point of which is to disallow text in the field whilst allowing for various punctuation styles. Hoping to avoid re-inventing the whole system, I'd like to be able to allow certain text, i.e. ext. or Ext. Any ideas? thx, mike YOU WROTE: You want to list all the alternatives, separated by vertical bars. For individual character alternatives, you can create a character class (a list or range of characters inside square brackets). For example: /^(?:()\d\s\|Eext\.)*$/ matches a series of (any combination of) only left-paren, right-paren, digits, whitespace, or Ext. or ext.	[reply] [d/l]
Re^4: Tweak for my Perl Regex that screens for digits only by hackermike (Novice) on Jan 25, 2006 at 20:50 UTC
`/^(?:[-()\d\s]\|[Ee]xt\.)*$/` matches a series of (any combination of) only hyphen, left-paren, right-paren, digits, whitespace, or Ext. or ext. Updated: added the hyphen. Note that a hyphen, if it appears in a character class, must be the first listed character (so that it doesn't look like part of a character range). THANKS! My seeking help with making the ext. permissible actually solved two problems, as ikegami pointed out, my poor effort was not even doing what I thought it would! Now if there only some way for perl to limit the number of characters in a text field, (not a text area and not the phone field)so they can't enter whole paragraphs in the title field............ Mike	[reply] [d/l]
Re^5: Tweak for my Perl Regex that screens for digits only by Roy Johnson (Monsignor) on Jan 25, 2006 at 20:57 UTC
You can truncate a string variable to whatever length you like by using substr. `substr($text_field, 100) = '' if length($text_field) > 100;` [download] will truncate `$text_field` to 100 chars. Or you could have your program just abort if it received an oversized field. Caution: Contents may have been coded under pressure.	[reply] [d/l] [select]
Re^6: Tweak for my Perl Regex that screens for digits only by hackermike (Novice) on Jan 26, 2006 at 07:48 UTC
Re^7: Tweak for my Perl Regex that screens for digits only by Roy Johnson (Monsignor) on Jan 26, 2006 at 15:52 UTC
Some notes below your chosen depth have not been shown here
Re^3: Tweak for my Perl Regex that screens for digits only by ikegami (Patriarch) on Jan 25, 2006 at 19:35 UTC
When text or letters are input the regex generates an error msg, Disallowing is a form of validation. And your regexp doesn't disallow what you claim it disallows. If there's a digit anywhere in the string, it doesn't generate an error message. `foreach ( '416-967-1111', 'I had 2 glasses of orange juice with my breakfast', 'I had two glasses of orange juice with my breakfast', ) { unless (/\s$$\.\d+\-\s/) { print("error message\n"); } else { print("no error message\n"); } }` [download] outputs `no error message no error message error message` [download] rather than the desired `no error message error message error message` [download]	[reply] [d/l] [select]
Re^4: Tweak for my Perl Regex that screens for digits only by hackermike (Novice) on Jan 25, 2006 at 20:34 UTC
Thanks for your reply-- I only meant to say that I'm not trying to validate that the submitted numbers are in fact a phone number. You are correct, the "regex" I hacked up does not do what I thought it did. I did not test sufficient possibilites. Thanks for pointing that out. Clearly I needed even more assistance than I asked for. It's been something of a ,necessary) game deterring the spammers. I don't want to deter the legit posters with too many hurdles, and yet make it too much work for the spammers to be working my forms. The testing I could think of indicates Roy's regex will allow whatever numbers are entered but no text other than the ext. thx Mike	[reply]
Re^5: Tweak for my Perl Regex that screens for digits only by ikegami (Patriarch) on Jan 25, 2006 at 20:49 UTC
Maybe you should consider a statistical approach. You could use an absolute tolerance: `my $good_chars = $FORM{'phone'} =~ tr/-()0-9. //; $good_chars += 3 if $FORM{'phone'} =~ /ext/i; if (length($FORM{'phone'} - $good_chars) > 4) { # Accept <= 4 bad # Bad phone number! ... }` [download] or a relative tolerance: `my $good_chars = $FORM{'phone'}) =~ tr/-()0-9. //; $good_chars += 3 if $FORM{'phone'} =~ /ext/i; if ($good_chars / length($FORM{'phone'} < 0.80) { # Accept <= 20% bad # Bad phone number! ... }` [download] It would probably be more reliable than trying to find out all the valid characters.	[reply] [d/l] [select]


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