- Regular expression data. Requires a regular expres-
- sion <STRONG>(char</STRONG> <STRONG>*)</STRONG> third argument; the data is valid if
- the regular expression matches it. Regular expres-
- sions are in the format of <STRONG><A HREF="regcomp.3x.html">regcomp(3x)</A></STRONG> and
- <STRONG><A HREF="regexec.3x.html">regexec(3x)</A></STRONG>. Please notice that the regular expres-
- sion must match the whole field. If you have for
- example an eight character wide field, a regular
- expression "^[0-9]*$" always means that you have to
- fill all eight positions with digits. If you want to
- allow fewer digits, you may use for example "^[0-9]*
- *$" which is good for trailing spaces (up to an empty
- field), or "^ *[0-9]* *$" which is good for leading
- and trailing spaces around the digits.
+ Regular expression data. Requires a regular expression <STRONG>(char</STRONG> <STRONG>*)</STRONG>
+ third argument; the data is valid if the regular expression
+ matches it. Regular expressions are in the format of <STRONG>regcomp</STRONG> and
+ <STRONG>regexec</STRONG>. Please notice that the regular expression must match the
+ whole field. If you have for example an eight character wide
+ field, a regular expression "^[0-9]*$" always means that you have
+ to fill all eight positions with digits. If you want to allow
+ fewer digits, you may use for example "^[0-9]* *$" which is good
+ for trailing spaces (up to an empty field), or "^ *[0-9]* *$"
+ which is good for leading and trailing spaces around the digits.