User manual

mikroC PRO for PIC32
MikroElektronika
109
Metacharacters - Predened classes
\w - an alphanumeric character (including "_")
\W - a nonalphanumeric character
\d - a numeric character
\D - a non-numeric character
\s - any space (same as [\t\n\r\f])
\S - a non space
You may use \w, \d and \s within custom character classes.
Example:
routi\de - matches strings like 'routi1e', 'routi6e' and so on, but not 'routine', 'routime' and
so on.
Metacharacters - Word boundaries
A word boundary ("\b") is a spot between two characters that has an alphanumeric character ("\w") on one side,
and a nonalphanumeric character ("\W") on the other side (in either order), counting the imaginary characters off the
beginning and end of the string as matching a "\W".
\b - match a word boundary)
\B - match a non-(word boundary)
Metacharacters - Iterators
Any item of a regular expression may be followed by another type of metacharacters - iterators. Using this
metacharacters,you can specify number of occurences of previous character, metacharacter or subexpression.
* - zero or more (“greedy”), similar to {0,}
+ - one or more (“greedy”), similar to {1,}
? - zero or one (“greedy”), similar to {0,1}
{n} - exactly n times (“greedy”)
{n,} - at least n times (“greedy”)
{n,m} - at least n but not more than m times (“greedy”)
*? - zero or more (“non-greedy”), similar to {0,}?
+? - one or more (“non-greedy”), similar to {1,}?
?? - zero or one (“non-greedy”), similar to {0,1}?
{n}? - exactly n times (“non-greedy”)
{n,}? - at least n times (“non-greedy”)
{n,m}? - at least n but not more than m times (“non-greedy”)
So, digits in curly brackets of the form, {n,m}, specify the minimum number of times to match the item n and the
maximum m. The form {n} is equivalent to {n,n} and matches exactly n times. The form {n,} matches n or more
times. There is no limit to the size of n or m, but large numbers will chew up more memory and slow down execution.
If a curly bracket occurs in any other context, it is treated as a regular character.