strings.sgml

GLib是GTK+和GNOME工程的基础底层核心程序库

<!-- ##### SECTION Title ##### -->
Strings

<!-- ##### SECTION Short_Description ##### -->
text buffers which grow automatically as text is added.

<!-- ##### SECTION Long_Description ##### -->
<para>
A #GString is similar to a standard C string, except that it grows automatically
as text is appended or inserted. Also, it stores the length of the string, so
can be used for binary data with embedded nul bytes.
</para>

<!-- ##### SECTION See_Also ##### -->
<para>

</para>

<!-- ##### STRUCT GString ##### -->
<para>
The #GString struct contains the public fields of a #GString.
The <structfield>str</structfield> field points to the character data.
It may move as text is added.
The <structfield>len</structfield> field contains the length of the string,
not including the terminating nul character.
</para>
<para>
The <structfield>str</structfield> field is nul-terminated and so can be used as an ordinary C
string. But it may be moved when text is appended or inserted into the
string.
</para>

@str: 
@len: 
@allocated_len: 

<!-- ##### FUNCTION g_string_new ##### -->
<para>
Creates a new #GString, initialized with the given string.
</para>

@init: the initial text to copy into the string.
@Returns: the new #GString.


<!-- ##### FUNCTION g_string_new_len ##### -->
<para>
Creates a new #GString with @len bytes of the @init buffer.  Because a length is
provided, @init need not be nul-terminated, and can contain embedded nul bytes.
</para>

@init: initial contents of string.
@len: length of @init to use.
@Returns: a new #GString.


<!-- ##### FUNCTION g_string_sized_new ##### -->
<para>
Creates a new #GString, with enough space for @dfl_size characters.
This is useful if you are going to add a lot of text to the string and
don't want it to be reallocated too often.
</para>

@dfl_size: the default size of the space allocated to hold the string.
@Returns: the new #GString.


<!-- ##### FUNCTION g_string_assign ##### -->
<para>
Copies the characters from one #GString into another, destroying any previous
contents. It is rather like the standard <function>strcpy()</function> function, except that
you do not have to worry about having enough space to copy the string.
</para>

@string: the destination #GString. Its current contents are destroyed.
@rval: the source #GString.
@Returns: the destination #GString.


<!-- ##### MACRO g_string_sprintf ##### -->
<para>
Writes a formatted string into a #GString.
This is similar to the standard <function>sprintf()</function> function,
except that the #GString buffer automatically expands to contain the results.
The previous contents of the #GString are destroyed. This
function has been renamaed to g_string_printf().
</para>

<!-- # Unused Parameters # -->
@string: a #GString.
@format: the string format. See the <function>sprintf()</function>
documentation.
@Varargs: the parameters to insert into the format string.


<!-- ##### MACRO g_string_sprintfa ##### -->
<para>
Appends a formatted string onto the end of a #GString.
This function is is similar to g_string_sprintf() except that
the text is appended to the #GString. The function has been
renamed to g_string_append_printf().
</para>

<!-- # Unused Parameters # -->
@string: a #GString.
@format: the string format. See the <function>sprintf()</function>
documentation.
@Varargs: the parameters to insert into the format string.


<!-- ##### FUNCTION g_string_printf ##### -->
<para>
Writes a formatted string into a #GString.
This is similar to the standard <function>sprintf()</function> function,
except that the #GString buffer automatically expands to contain the results.
The previous contents of the #GString are destroyed.
</para>

@string: a #GString.
@format: the string format. See the <function>printf()</function>
documentation.
@Varargs: the parameters to insert into the format string.


<!-- ##### FUNCTION g_string_append_printf ##### -->
<para>
Appends a formatted string onto the end of a #GString.
This function is is similar to g_string_printf() except that
the text is appended to the #GString.
</para>

@string: a #GString.
@format: the string format. See the <function>printf()</function>
documentation.
@Varargs: the parameters to insert into the format string.


<!-- ##### FUNCTION g_string_append ##### -->
<para>
Adds a string onto the end of a #GString, expanding it if necessary.
</para>

@string: a #GString.
@val: the string to append onto the end of the #GString.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_append_c ##### -->
<para>
Adds a character onto the end of a #GString, expanding it if necessary.
</para>

@string: a #GString.
@c: the character to append onto the end of the #GString.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_append_unichar ##### -->
<para>

</para>

@string: 
@wc: 
@Returns: 


<!-- ##### FUNCTION g_string_append_len ##### -->
<para>
Appends @len bytes of @val to @string. Because @len is provided, 
@val may contain embedded nuls and need not be nul-terminated.
</para>

@string: a #GString.
@val: bytes to append.
@len: number of bytes of @val to use.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_prepend ##### -->
<para>
Adds a string on to the start of a #GString, expanding it if necessary.
</para>

@string: a #GString.
@val: the string to prepend on the start of the #GString.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_prepend_c ##### -->
<para>
Adds a character onto the start of a #GString, expanding it if necessary.
</para>

@string: a #GString.
@c: the character to prepend on the start of the #GString.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_prepend_unichar ##### -->
<para>

</para>

@string: 
@wc: 
@Returns: 


<!-- ##### FUNCTION g_string_prepend_len ##### -->
<para>
Prepends @len bytes of @val to @string. Because @len is provided, 
@val may contain embedded nuls and need not be nul-terminated.
</para>

@string: a #GString.
@val: bytes to prepend.
@len: number of bytes in @val to prepend.
@Returns: the #GString passed in.


<!-- ##### FUNCTION g_string_insert ##### -->
<para>
Inserts a copy of a string into a #GString, expanding it if necessary.
</para>

@string: a #GString.
@pos: the position to insert the copy of the string.
@val: the string to insert.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_insert_c ##### -->
<para>
Inserts a character into a #GString, expanding it if necessary.
</para>

@string: a #GString.
@pos: the position to insert the character.
@c: the character to insert.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_insert_unichar ##### -->
<para>

</para>

@string: 
@pos: 
@wc: 
@Returns: 


<!-- ##### FUNCTION g_string_insert_len ##### -->
<para>
Inserts @len bytes of @val into @string at @pos.  Because @len is provided, @val
 may contain embedded nuls and need not be nul-terminated. If @pos is -1, bytes are inserted at the end of the string.
</para>

@string: a #GString.
@pos: position in @string where insertion should happen, or -1 for at the end.
@val: bytes to insert.
@len: number of bytes of @val to insert.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_erase ##### -->
<para>
Removes @len characters from a #GString, starting at position @pos.
The rest of the #GString is shifted down to fill the gap.
</para>

@string: a #GString.
@pos: the position of the characters to remove.
@len: the number of characters to remove, or -1 to remove all
      following characters.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_truncate ##### -->
<para>
Cuts off the end of the GString, leaving the first @len characters.
</para>

@string: a #GString.
@len: the new size of the #GString.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_set_size ##### -->
<para>

</para>

@string: 
@len: 
@Returns: 


<!-- ##### FUNCTION g_string_free ##### -->
<para>
Frees the memory allocated for the #GString.
If @free_segment is %TRUE it also frees the character data.
</para>

@string: a #GString.
@free_segment: if %TRUE the actual character data is freed as well.
@Returns: 


<!-- ##### FUNCTION g_string_up ##### -->
<para>
Converts a #GString to upper case.
</para>

@string: a #GString.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_down ##### -->
<para>
Converts a #GString to lower case.
</para>

@string: a #GString.
@Returns: the #GString.


<!-- ##### FUNCTION g_string_hash ##### -->
<para>
Creates a hash code for @str; for use with #GHashTable.
</para>

@str: a string to hash.
@Returns: hash code for @str.


<!-- ##### FUNCTION g_string_equal ##### -->
<para>
Compares two strings for equality, returning %TRUE if they are equal. 
For use with #GHashTable.
</para>

@v: a #GString.
@v2: another #GString.
@Returns: %TRUE if they strings are the same length and contain the same bytes.