A regular term describes a certain quantity of character strings. These terms are determined with syntactic rules.

Character Description
x The letter “x”
[abc] a, b, or c
[^abc] Each character except a, b, or c
[a-z] Each small letter
. An arbitrary character
? The previous term must appear only once or not at all {0,1}
+ The previous term can appear once or as often as requiered {1,∞}
* The previous term can appear as often as requiered but does not have to appear at all {0,∞}
Repeals the meaning of the following character (e.g. “.” stands for “.”)

 

Examples:

Regular Term
Description
.*\.csv All character strings, that end with “.csv”
[a-zA-Z0-9]*\.xls Any number of letters and numerical digits, and ending with “.xls”
Sensor.* All character strings, that begin with Sensor and end at will (Sensor1, SensorX, SensorSynavision)
file.\.txt All character strings, that begin with file, have any additional character and end with “.txt” (Datei1.txt, DateiP.txt)
A[0-9]*\.csv All character strings, that begin with “A”, have any number of additional numerical digits and end with “.csv” (A0192.csv, A.csv, A4.csv)