Parameters | Utilities | File Filter Expression

File Filter Expression
Specify a filter, using regular expression syntax, by which to filter files.
This feature relies on the SAS PRXPARSE function, which uses metacharacters in constructing a Perl regular expression. This expression is applied to the whole filename including the extension. A few of the most common uses are given below.
Single alphanumeric string. The filter “dat” (without the quotation marks) would show all .dat files but also .sas7bdat files or any filename that contains “dat”.
Single file extension. To display .dat files only, you can specify “\.dat” (without the quotation marks). Note the backslash (\) preceding the period. The period normally is interpreted as a metacharacter, which matches any single character, so the backlash overrides the normal use of the period metacharacter and instead forces interpretation of the literal period.
Multiple file extensions. To display files with .txt, .dat, or .abc extensions only, specify “\.txt|\.dat|\.abc” (without the quotation marks). Note the use of the vertical bar (|) as an OR operator.
Specific file base and extension. To display any .txt file starting with the word “test” in its base (such as test001.txt, test002.txt, testnnn.txt), specify “^test*\.txt” (without the quotation marks). Note the use of the caret (^) to indicate that matches should be made at the beginning of the filename (this avoids displaying a file such as firsttest001.txt).
The examples above only touch the surface of what is possible using the powerful regular expression syntax. Refer to the SAS Online Documentation for the PRXPARSE function for additional details.
To Specify a File Filter Expression: