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Regular Expressions

Regular expressions are defined search patterns that you can use to search for complex search expressions in a string list.

Regular expressions are often avoided, even by experienced programmers, because of their complexity and their very cryptic appearance - but they are very powerful search tools.

A few examples of the syntax of regular expressions

NameSyntaxDescription
Wildcard character.The dot represents a wildcard character. The expression str.ng, for example, will find string or strang.
Quantity of characters[ab]Searches for one of the specified characters. str[ia]ng, for example, will find string or strang, but not strung.
Character range[a-z]Searches for one of the characters in the specified range. str[a-j]ng, for example, will find string or strang, but not strung.
Characters outside of the range[^a-z]Searches for one of the characters that is not within the specified range. str[^a-j]ng, for example, will find strung, but not string.
Start of line.^Searches for a start of line. ^op will find op in open menu, but not in top menu.
End of line$Searches for an end of line. ^nu will find nu in open menu, but not in menu text.
0 or more matches*The preceding expression may appear never, once or several times. te+st will find tst, test or teeeest.
1 or more matches.+The preceding expression may appear once or several times. te+st will find test or teeeest, but not test.
Group()Puts a sub-expression into a group. (te)+st will find test or tetest, but not teest.
Or|Finds one of the specified sub-expressions, (stri|stra)ng finds string or strang.

The library for regular expressions used by SDL Passolo is fully compatible with the syntax of Perl 5. For further information on Perl and especially on regular expressions, please consult the Internet or relevant reference works.