60 second basic problem -.-

[stupot2212]

I know how simple this must be

But I have spent almost 5 hours now -.-

 

If it makes any difference, its for use within WHMCS custom fields validation..

 

 

All that I want, is to use a regular expression to check that my input field is :

A single word - no spaces and only lower case A to Z letters.. no spaces, no -'s no nothing

 

I am either really stupid or too tired.

Would appreciate any help very much

 

[cags]

if(preg_match("#^[a-z]+$#D", $input)) {
  echo "Valid";
}

[stupot2212]

Thankyou very much! 

 

#^[a-z]+$#D

 

I understand this much of it : ^[a-z]+$

I had actually tried that before

 

If anyone care's to explain the # and #D it would be beneficial for me and others

 

Thanks again man!

[salathe]

The # are delimiters, they delimit (mark the start and end points of) the regular expression contained within.  They are required because in the PCRE family of functions (preg_*) the regular expression is combined with some (optional) modifiers which affect the behaviour of the expression. The delimiters, regular expression and modifiers combined are called a pattern.

 

Given the pattern /hello/i then the parts are:

• Delimiter is /
  
• Regular expression is hello
  
• Modifier is i (makes the expression match case-insensitively)
  

 

The delimiters are most commonly one of /, ~, # or @. Far more characters are allowed as delimiters but it is not important at this stage to know precisely which ones.

 

The D modifier in cags' pattern affects the behaviour of the $ character in the regular expression. Normally (i.e., without the D modifier; lets ignore multiline mode and character classes for now) the $ matches the point right at the end of the subject string, or immediately before a newline at the end of the subject string if there is one.

 

To give an example: /def$/ matches the string "abcdef" and also "abcdef\n".  When the D modifier is used, the second example (with a trailing newline) will not be matched.  It is often used just to be that extra little bit sure that the subject string does not contain a trailing newline. An alternative, not wanting to confuse you, is to use the \z escape sequence which will only ever match at the very end of the subject string: /def\z/ will match "abcdef" but not "abcdef\n"

[newbtophp]

You may also find this useful:

 

http://www.phpguru.org/downloads/PCRE%20Cheat%20Sheet/PHP%20PCRE%20Cheat%20Sheet.pdf

 

[salathe]

You may also find this useful: …

 

Interestingly, that cheat sheet completely forgets to mention the D modifier.

[milliclark]

I think you have got the solution of your problem so nothing to say....