Siemens SINUMERIK 840D sl Operating Manual page 87

Constructs
Meta charac‐
ters
Quantifier
Using quantifiers, you can specify how many times a specific component of a regular
expression must occur in order for a found character string to be considered a match. A
quantification expression is valid for the character or character set which is located directly in
front of it.
Meta charac‐
ters
SINUMERIK Integrate Create MyConfig - Diff, Expert, Topo
Operating Manual, 11/2016, A5E36537479B-AD
Several regular expressions can be combined to form a single one using alternation
|
(logical OR).
Example: cat|dog|tiger. (cat or dog or tiger)
The match to the far left has priority.
The grouping is used to combine parts of regular expressions and to limit the range
( )
of validity of an alternation.
Example: _(abc|xyz)_
The meta character for the beginning of the line does not describe a character in the
^
actual sense, but instead a position in a line.
Example: ^[aA] requires a lower-case a or upper-case A at the beginning of the line.
The ^ character in square brackets has a different meaning, it is used as negation
of the character string.
The meta character for the end of the line does not describe a character in the actual
$
sense, but instead a position in a line.
Example: [aA]$ requires a lower-case a or an upper-case A at the end of the line.
Requires a null or a match.
?
Example: _? or (abc|xyz)?.
Requires one or any number of matches.
+
Example: a+ or [0-9]+.
Requires null or any number of matches.
*
Example: \w* or (abc)*.
Requires precisely n matches.
{n}
Example: (abc){2}.
Requires a minimum of n matches, but there can also be more.
{n,}
Example: (abc){2,}.
Requires at least n matches, however a maximum of m matches.
{n,m}
Example: \w {2,17}.
Create MyConfig - Diff
A Use of regular expressions in Diff
Description
Description
87