The Softek Barcode Reader SDK and our BardecodeFiler Windows application both use ‘regex’ pattern matching for matching barcode values. We often get asked advice on how to build a regex so we thought a short guide to the basics might be useful.<\/p>\n
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Here is a simple example:<\/p>\n
^\\d{5}$<\/p>\n
So let’s break it down:<\/p>\n
^ means the start of the barcode<\/p>\n
$ means the end of the barcode<\/p>\n
\\d means any digit 0 to 9 and the {5} after means that the digit should be repeated 5 times.<\/p>\n
So this will match a barcode with value 12345 but will not match 1234 or 123456<\/p>\n
If you miss out the ^ and $ symbols then the barcode just needs to contain 5 digits somewhere. In this case a barcode of value 123456 would also match because it contains 5 consecutive digits.<\/p>\n
If you want to match between 4 and 6 digits you would use \\d{4,6} rather than \\d{5}.<\/p>\n
You could also use \\d+ to match 1 or more digits or \\d* to match 0 to any number of digits.<\/p>\n
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In addition to \\d you could also use:<\/p>\n
\\s to match anything that is white space<\/p>\n
\\S to match anything that is not white space<\/p>\n
\\D to match anything that is not a digit<\/p>\n
\\w to match A-Z a-z 0-9 and _ (underscore)<\/p>\n
\\W to match anything that is not included in \\w<\/p>\n
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You can also match a specific set of characters using []. For example, if your barcodes all begin with 3 letters A, B and C in any order followed by 5 digits (e.g ABC12345 or CBA98765) then you could use:<\/p>\n
^[A-C]{3}\\d{5}$<\/p>\n
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If your barcodes all start with a fixed pattern such as POD, followed say by 8 digits then you would use:<\/p>\n
^POD\\d{8}$<\/p>\n
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The above hardly scratches the surface of what a regex can do but there are plenty of resources available:<\/p>\n
For a more extensive basic guide try the following link:<\/p>\n