HFS: File masks: Difference between revisions

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== Cos'è? ==
== What is it? ==


Una maschera file ('''''"file mask"''''') denota un set di files.<br>Un esempio potrebbe essere il seguente: <tt>*.jpg;*.gif</tt>.<br>Questo modello denota ogni file con estensione .jpeg e .gif. <br>
A file mask denotes a set of files. It is usually something like this: <tt>*.jpg;*.gif</tt>. This example denotes any jpeg and gif files.  
Ricorda che i caratteri usati nei nomi dei files non sono '''''"case sensitive"''''': per cui <tt>*.jpg</tt> e <tt>*.JPG</tt> (cioè scritto in minuscolo e/o maiuscolo) riferisce esattamente allo stesso set di files.
Remember that the characters used in filenames are not case sensitive: so <tt>*.jpg</tt> and <tt>*.JPG</tt> refer to exactly the same set of files.


== Come funziona? ==
== How does it work? ==


L'esempio precedente mostra una ''doppia'' maschera file.<br>Presenta due elementi separati da punto e virgola (;): ''*.jpg''
The example above shows a ''double'' file mask. It has two atoms separated by the semicolon: ''*.jpg''
e ''*.gif''.<br>Il punto e virgola è utilizzato per unire maschere multiple essendo, infatti, un carattere'' "speciale"''.<br>Nelle maschere file possono esistere esclusivamente tre tipi di carattere speciale: ''';''' '''*''' e '''?'''.
and ''*.gif''. The semicolon is used to merge multiple masks: it is a ''special'' character.
There are only three special characters in file masks: ''';''' '''*''' and '''?'''.


== L'asterisco (*) ==
== The star (*) ==


The star (also called "asterisk") stands for ''any string'' of characters. If the mask contains only the star, it matches ANY file.
The star (also called "asterisk") stands for ''any string'' of characters. If the mask contains only the star, it matches ANY file.
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but also ''A.jpg''.
but also ''A.jpg''.


== Il punto interrogativo (?) ==
== The question mark (?) ==


This stands for a ''single character''. Something like <tt>A?B</tt> matches any filename that is three characters long and starts with an A and ends with a B. The length is fixed to three characters because ? can be replaced by
This stands for a ''single character''. Something like <tt>A?B</tt> matches any filename that is three characters long and starts with an A and ends with a B. The length is fixed to three characters because ? can be replaced by
only one character. Thus the ? does not match the null string as the * does.
only one character. Thus the ? does not match the null string as the * does.
==Inverting the logic (\) ==
So you want to hide filetypes, instead of showing specific filetypes?
Insert a backslash <tt>\</tt> before <tt>*.ext</tt> to achieve opposite logic with the filter, and hide the filetypes you do not want visible to users. E.g <tt>\*.db;*.ini</tt>

Latest revision as of 10:48, 8 February 2008

What is it?

A file mask denotes a set of files. It is usually something like this: *.jpg;*.gif. This example denotes any jpeg and gif files. Remember that the characters used in filenames are not case sensitive: so *.jpg and *.JPG refer to exactly the same set of files.

How does it work?

The example above shows a double file mask. It has two atoms separated by the semicolon: *.jpg and *.gif. The semicolon is used to merge multiple masks: it is a special character. There are only three special characters in file masks: ; * and ?.

The star (*)

The star (also called "asterisk") stands for any string of characters. If the mask contains only the star, it matches ANY file.

If you put an A before the star A*, it matches any file starting with an A.

If you put an A after the star *A, it matches any file ending with an A.

A*B matches any file starting with an A and ending with a B. The example above shows *.jpg : it matches any file ending with .jpg (that is, jpeg images). jpeg files are relatively unusual because they sometimes end with .jpeg and more rarely with .jpe . (The part of a filename that comes after the period is called the file "extension", and is normally limited to three characters.) You could use the mask .jp* to match all types of jpeg files.

The star also matches the null string: A*.jpg matches files like A1.jpg , Adfgg.jpg but also A.jpg.

The question mark (?)

This stands for a single character. Something like A?B matches any filename that is three characters long and starts with an A and ends with a B. The length is fixed to three characters because ? can be replaced by only one character. Thus the ? does not match the null string as the * does.


Inverting the logic (\)

So you want to hide filetypes, instead of showing specific filetypes?

Insert a backslash \ before *.ext to achieve opposite logic with the filter, and hide the filetypes you do not want visible to users. E.g \*.db;*.ini