patterns.sgml   [plain text]

<!-- ##### SECTION Title ##### -->
Glob-style pattern matching

<!-- ##### SECTION Short_Description ##### -->
matches strings against patterns containing '*' (wildcard) and '?' (joker).

<!-- ##### SECTION Long_Description ##### -->
<para>
The <function>g_pattern_match*</function> functions match a string 
against a pattern containing '*' and '?' wildcards with similar semantics 
as the standard <function>glob()</function> function: '*' matches an
arbitrary, possibly empty, string, '?' matches an arbitrary character.
</para>
<para>
Note that in contrast to <function>glob()</function>, the '/' character
<emphasis>can</emphasis> be matched by the wildcards, there are no
'[...]' character ranges and '*' and '?' can <emphasis>not</emphasis>
be escaped to include them literally in a pattern. 
</para>
<para>
When multiple strings must be matched against the same pattern, it
is better to compile the pattern to a #GPatternSpec using 
g_pattern_spec_new() and use g_pattern_match_string() instead of 
g_pattern_match_simple().  This avoids the overhead of repeated 
pattern compilation.
</para>

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<para>

</para>

<!-- ##### STRUCT GPatternSpec ##### -->
<para>
A <structname>GPatternSpec</structname> is the 'compiled' form of a pattern.
This structure is opaque and its fields cannot be accessed directly.
</para>


<!-- ##### FUNCTION g_pattern_spec_new ##### -->
<para>
Compiles a pattern to a #GPatternSpec.
</para>

@pattern: a zero-terminated UTF-8 encoded string.
@Returns: a newly-allocated #GPatternSpec.


<!-- ##### FUNCTION g_pattern_spec_free ##### -->
<para>
Frees the memory allocated for the #GPatternSpec.
</para>

@pspec: a #GPatternSpec.


<!-- ##### FUNCTION g_pattern_spec_equal ##### -->
<para>
Compares two compiled pattern specs and returns whether they
will match the same set of strings.
</para>

@pspec1: a #GPatternSpec.
@pspec2: another #GPatternSpec.
@Returns: Whether the compiled patterns are equal.


<!-- ##### FUNCTION g_pattern_match ##### -->
<para>
Matches a string against a compiled pattern. Passing the correct length of the
string given is mandatory. The reversed string can be omitted by passing %NULL,
this is more efficient if the reversed version of the string to be matched is
not at hand, as g_pattern_match() will only construct it if the compiled pattern
requires reverse matches.
</para>
<para>
Note that, if the user code will (possibly) match a string against a multitude 
of patterns containing wildcards, chances are high that some patterns will 
require a reversed string. In this case, it's more efficient to provide the 
reversed string to avoid multiple constructions thereof in the various calls to
g_pattern_match().
</para>
<para>
Note also that the reverse of a UTF-8 encoded string can in general 
<emphasis>not</emphasis> be obtained by <function>g_strreverse()</function>.
This works only if the string doesn't contain any multibyte characters.
Glib doesn't currently offer a function to reverse UTF-8 encoded strings.
</para>

@pspec: a #GPatternSpec.
@string_length: the length of @string.
@string: the UTF-8 encoded string to match.
@string_reversed: the reverse of @string or %NULL.
@Returns: %TRUE if @string matches @pspec.


<!-- ##### FUNCTION g_pattern_match_string ##### -->
<para>
Matches a string against a compiled pattern. If the string is to
be matched against more than one pattern, consider using
g_pattern_match() instead while supplying the reversed string.
</para>

@pspec: a #GPatternSpec.
@string: the UTF-8 encoded string to match.
@Returns: %TRUE if @string matches @pspec.


<!-- ##### FUNCTION g_pattern_match_simple ##### -->
<para>
Matches a string against a pattern given as a string.
If this function is to be called in a loop, it's more efficient to compile
the pattern once with g_pattern_spec_new() and call g_pattern_match_string()
repetively.
</para>

@pattern: the UTF-8 encoded pattern.
@string: the UTF-8 encoded string to match.
@Returns: %TRUE if @string matches @pspec.