Editing Regular Expressions

Regular expressions are used in [[Filename_Filters|filename filters]] as a way to filter files on either the client or server side.

There's no documentation anywhere about the type of regular expressions used by FileZilla, so the following is what I've been able to glean through experimentation.

Note that by selecting "None of the following" as a [[Filename_Filters|file filter criteria type]], you can effectively select those files that ''do'' match the specified criteria.

= Regular Expressions Match Anywhere In The Name =

Unless anchored to the beginning or the end of the file name, they will match if they occur anywhere inside the file name. See the '^' and '$' characters.

Thus, if your regular expression is 'x', then any filename that contains the letter x anywhere will match (beginning, middle, or end).

= All Non-Special Characters =

All characters not specified below will match exactly in the filename. Thus, the regular expression 'foo' will match "foobar", "barfoo", and "quxfoobaz".

= The '.' Character =

The '.' character matches any single character. Thus, 'd.t' matches both "dat" and "dot".

= The '*' Character =

The '*' character matches 0 or more of the preceding token. Thus, 'foo.*bar' matches both "fooquxbar" and "foobar". The regular expression 'ge*k' matches "gk", "gek", "geek", and "geeeeeeeeeeeeeeeek".

= The '?' Character =

The '?' character matches 0 or 1 of the preceding token. Thus, 'gee?k' matches "gek" and "geek", but not "gk" or "geeek".

= The '^' Character =

The '^' character matches the beginning of the filename. Thus, '^x' matches all file whose names begin with the letter 'x'.

= The '$' Character =

The '$' character matches the end of the filename. Thus, 'x$' matches all files whose names end with the letter 'x'.

= The '\' Character =

This character escapes the following token, so that it does not take on special meaning. For example, if you wanted to filter for files that begin with a period, then the regular expression '^\.' would accomplish that for you. If you had just specified '^.', you would have matched all files that began with any single character.