glib.CharacterSet.CharacterSet Class Reference

List of all members.

Detailed Description

Description File Name Encodings Historically, Unix has not had a defined encoding for file names: a file name is valid as long as it does not have path separators in it ("/").

However, displaying file names may require conversion: from the character set in which they were created, to the character set in which the application operates. Consider the Spanish file name "Presentacin.sxi". If the application which created it uses ISO-8859-1 for its encoding, then the actual file name on disk would look like this: Character: P r e s e n t a c i n . s x i Hex code: 50 72 65 73 65 6e 74 61 63 69 f3 6e 2e 73 78 69 However, if the application use UTF-8, the actual file name on disk would look like this: Character: P r e s e n t a c i n . s x i Hex code: 50 72 65 73 65 6e 74 61 63 69 c3 b3 6e 2e 73 78 69 Glib uses UTF-8 for its strings, and GUI toolkits like GTK+ that use Glib do the same thing. If you get a file name from the file system, for example, from readdir(3) or from g_dir_read_name(), and you wish to display the file name to the user, you will need to convert it into UTF-8. The opposite case is when the user types the name of a file he wishes to save: the toolkit will give you that string in UTF-8 encoding, and you will need to convert it to the character set used for file names before you can create the file with open(2) or fopen(3). By default, Glib assumes that file names on disk are in UTF-8 encoding. This is a valid assumption for file systems which were created relatively recently: most applications use UTF-8 encoding for their strings, and that is also what they use for the file names they create. However, older file systems may still contain file names created in "older" encodings, such as ISO-8859-1. In this case, for compatibility reasons, you may want to instruct Glib to use that particular encoding for file names rather than UTF-8. You can do this by specifying the encoding for file names in the G_FILENAME_ENCODING environment variable. For example, if your installation uses ISO-8859-1 for file names, you can put this in your ~/.profile: export G_FILENAME_ENCODING=ISO-8859-1 Glib provides the functions g_filename_to_utf8() and g_filename_from_utf8() to perform the necessary conversions. These functions convert file names from the encoding specified in G_FILENAME_ENCODING to UTF-8 and vice-versa. Figure1, Conversion between File Name Encodings illustrates how these functions are used to convert between UTF-8 and the encoding for file names in the file system. Figure1.Conversion between File Name Encodings Checklist for Application Writers This section is a practical summary of the detailed description above. You can use this as a checklist of things to do to make sure your applications process file name encodings correctly. If you get a file name from the file system from a function such as readdir(3) or gtk_file_chooser_get_filename(), you do not need to do any conversion to pass that file name to functions like open(2), rename(2), or fopen(3) those are "raw" file names which the file system understands. If you need to display a file name, convert it to UTF-8 first by using g_filename_to_utf8(). If conversion fails, display a string like "Unknown file name". Do not convert this string back into the encoding used for file names if you wish to pass it to the file system; use the original file name instead. For example, the document window of a word processor could display "Unknown file name" in its title bar but still let the user save the file, as it would keep the raw file name internally. This can happen if the user has not set the G_FILENAME_ENCODING environment variable even though he has files whose names are not encoded in UTF-8. If your user interface lets the user type a file name for saving or renaming, convert it to the encoding used for file names in the file system by using g_filename_from_utf8(). Pass the converted file name to functions like fopen(3). If conversion fails, ask the user to enter a different file name. This can happen if the user types Japanese characters when G_FILENAME_ENCODING is set to ISO-8859-1, for example.


Static Public Member Functions

static char[] convert (char[] str, int len, char[] toCodeset, char[] fromCodeset, uint *bytesRead, uint *bytesWritten, GError **error)
 Converts a string from one character set to another.
static char[] convertWithFallback (char[] str, int len, char[] toCodeset, char[] fromCodeset, char[] fallback, uint *bytesRead, uint *bytesWritten, GError **error)
 Converts a string from one character set to another, possibly including fallback sequences for characters not representable in the output.
static char[] localeToUtf8 (char[] opsysstring, int len, uint *bytesRead, uint *bytesWritten, GError **error)
 Converts a string which is in the encoding used for strings by the C runtime (usually the same as that used by the operating system) in the current locale into a UTF-8 string.
static char[] filenameToUtf8 (char[] opsysstring, int len, uint *bytesRead, uint *bytesWritten, GError **error)
 Converts a string which is in the encoding used by GLib for filenames into a UTF-8 string.
static char[] filenameFromUtf8 (char[] utf8string, int len, uint *bytesRead, uint *bytesWritten, GError **error)
 Converts a string from UTF-8 to the encoding GLib uses for filenames.
static char[] filenameFromUri (char[] uri, char **hostname, GError **error)
 Converts an escaped ASCII-encoded URI to a local filename in the encoding used for filenames.
static char[] filenameToUri (char[] filename, char[] hostname, GError **error)
 Converts an absolute filename to an escaped ASCII-encoded URI, with the path component following Section 3.3.
static int getFilenameCharsets (char ***charsets)
 Determines the preferred character sets used for filenames.
static char[] filenameDisplayName (char[] filename)
 Converts a filename into a valid UTF-8 string.
static char[] filenameDisplayBasename (char[] filename)
 Returns the display basename for the particular filename, guaranteed to be valid UTF-8.
static char ** uriListExtractUris (char[] uriList)
 Splits an URI list conforming to the text/uri-list mime type defined in RFC 2483 into individual URIs, discarding any comments.
static char[] localeFromUtf8 (char[] utf8string, int len, uint *bytesRead, uint *bytesWritten, GError **error)
 Converts a string from UTF-8 to the encoding used for strings by the C runtime (usually the same as that used by the operating system) in the current locale.
static int getCharset (char **charset)
 Obtains the character set for the current locale; you might use this character set as an argument to g_convert(), to convert from the current locale's encoding to some other encoding.


Member Function Documentation

static char [] glib.CharacterSet.CharacterSet.convert ( char[]  str,
int  len,
char[]  toCodeset,
char[]  fromCodeset,
uint bytesRead,
uint bytesWritten,
GError **  error 
) [static]

Converts a string from one character set to another.

Note that you should use g_iconv() for streaming conversions[2]. str: the string to convert len: the length of the string, or -1 if the string is nul-terminated[1]. to_codeset: name of character set into which to convert str from_codeset: character set of str. bytes_read: location to store the number of bytes in the input string that were successfully converted, or NULL. Even if the conversion was successful, this may be less than len if there were partial characters at the end of the input. If the error G_CONVERT_ERROR_ILLEGAL_SEQUENCE occurs, the value stored will the byte offset after the last valid input sequence. bytes_written: the number of bytes stored in the output buffer (not including the terminating nul). error: location to store the error occuring, or NULL to ignore errors. Any of the errors in GConvertError may occur. Returns: If the conversion was successful, a newly allocated nul-terminated string, which must be freed with g_free(). Otherwise NULL and error will be set.

static char [] glib.CharacterSet.CharacterSet.convertWithFallback ( char[]  str,
int  len,
char[]  toCodeset,
char[]  fromCodeset,
char[]  fallback,
uint bytesRead,
uint bytesWritten,
GError **  error 
) [static]

Converts a string from one character set to another, possibly including fallback sequences for characters not representable in the output.

Note that it is not guaranteed that the specification for the fallback sequences in fallback will be honored. Some systems may do a approximate conversion from from_codeset to to_codeset in their iconv() functions, in which case GLib will simply return that approximate conversion. Note that you should use g_iconv() for streaming conversions[2]. str: the string to convert len: the length of the string, or -1 if the string is nul-terminated[1]. to_codeset: name of character set into which to convert str from_codeset: character set of str. fallback: UTF-8 string to use in place of character not present in the target encoding. (The string must be representable in the target encoding). If NULL, characters not in the target encoding will be represented as Unicode escapes or . bytes_read: location to store the number of bytes in the input string that were successfully converted, or NULL. Even if the conversion was successful, this may be less than len if there were partial characters at the end of the input. bytes_written: the number of bytes stored in the output buffer (not including the terminating nul). error: location to store the error occuring, or NULL to ignore errors. Any of the errors in GConvertError may occur. Returns: If the conversion was successful, a newly allocated nul-terminated string, which must be freed with g_free(). Otherwise NULL and error will be set.

static char [] glib.CharacterSet.CharacterSet.filenameDisplayBasename ( char[]  filename  )  [static]

Returns the display basename for the particular filename, guaranteed to be valid UTF-8.

The display name might not be identical to the filename, for instance there might be problems converting it to UTF-8, and some files can be translated in the display. If GLib can not make sense of the encoding of filename, as a last resort it replaces unknown characters with U+FFFD, the Unicode replacement character. You can search the result for the UTF-8 encoding of this character (which is "\357\277\275" in octal notation) to find out if filename was in an invalid encoding. You must pass the whole absolute pathname to this functions so that translation of well known locations can be done. This function is preferred over g_filename_display_name() if you know the whole path, as it allows translation. filename: an absolute pathname in the GLib file name encoding Returns: a newly allocated string containing a rendition of the basename of the filename in valid UTF-8 Since 2.6

static char [] glib.CharacterSet.CharacterSet.filenameDisplayName ( char[]  filename  )  [static]

Converts a filename into a valid UTF-8 string.

The conversion is not necessarily reversible, so you should keep the original around and use the return value of this function only for display purposes. Unlike g_filename_to_utf8(), the result is guaranteed to be non-NULL even if the filename actually isn't in the GLib file name encoding. If GLib can not make sense of the encoding of filename, as a last resort it replaces unknown characters with U+FFFD, the Unicode replacement character. You can search the result for the UTF-8 encoding of this character (which is "\357\277\275" in octal notation) to find out if filename was in an invalid encoding. If you know the whole pathname of the file you should use g_filename_display_basename(), since that allows location-based translation of filenames. filename: a pathname hopefully in the GLib file name encoding Returns: a newly allocated string containing a rendition of the filename in valid UTF-8 Since 2.6

static char [] glib.CharacterSet.CharacterSet.filenameFromUri ( char[]  uri,
char **  hostname,
GError **  error 
) [static]

Converts an escaped ASCII-encoded URI to a local filename in the encoding used for filenames.

uri: a uri describing a filename (escaped, encoded in ASCII). hostname: Location to store hostname for the URI, or NULL. If there is no hostname in the URI, NULL will be stored in this location. error: location to store the error occuring, or NULL to ignore errors. Any of the errors in GConvertError may occur. Returns: a newly-allocated string holding the resulting filename, or NULL on an error.

static char [] glib.CharacterSet.CharacterSet.filenameFromUtf8 ( char[]  utf8string,
int  len,
uint bytesRead,
uint bytesWritten,
GError **  error 
) [static]

Converts a string from UTF-8 to the encoding GLib uses for filenames.

Note that on Windows GLib uses UTF-8 for filenames; on other platforms, this function indirectly depends on the current locale. utf8string: a UTF-8 encoded string. len: the length of the string, or -1 if the string is nul-terminated. bytes_read: location to store the number of bytes in the input string that were successfully converted, or NULL. Even if the conversion was successful, this may be less than len if there were partial characters at the end of the input. If the error G_CONVERT_ERROR_ILLEGAL_SEQUENCE occurs, the value stored will the byte offset after the last valid input sequence. bytes_written: the number of bytes stored in the output buffer (not including the terminating nul). error: location to store the error occuring, or NULL to ignore errors. Any of the errors in GConvertError may occur. Returns: The converted string, or NULL on an error.

static char [] glib.CharacterSet.CharacterSet.filenameToUri ( char[]  filename,
char[]  hostname,
GError **  error 
) [static]

Converts an absolute filename to an escaped ASCII-encoded URI, with the path component following Section 3.3.

of RFC 2396. filename: an absolute filename specified in the GLib file name encoding, which is the on-disk file name bytes on Unix, and UTF-8 on Windows hostname: A UTF-8 encoded hostname, or NULL for none. error: location to store the error occuring, or NULL to ignore errors. Any of the errors in GConvertError may occur. Returns: a newly-allocated string holding the resulting URI, or NULL on an error.

static char [] glib.CharacterSet.CharacterSet.filenameToUtf8 ( char[]  opsysstring,
int  len,
uint bytesRead,
uint bytesWritten,
GError **  error 
) [static]

Converts a string which is in the encoding used by GLib for filenames into a UTF-8 string.

Note that on Windows GLib uses UTF-8 for filenames; on other platforms, this function indirectly depends on the current locale. opsysstring: a string in the encoding for filenames len: the length of the string, or -1 if the string is nul-terminated[1]. bytes_read: location to store the number of bytes in the input string that were successfully converted, or NULL. Even if the conversion was successful, this may be less than len if there were partial characters at the end of the input. If the error G_CONVERT_ERROR_ILLEGAL_SEQUENCE occurs, the value stored will the byte offset after the last valid input sequence. bytes_written: the number of bytes stored in the output buffer (not including the terminating nul). error: location to store the error occuring, or NULL to ignore errors. Any of the errors in GConvertError may occur. Returns: The converted string, or NULL on an error.

static int glib.CharacterSet.CharacterSet.getCharset ( char **  charset  )  [static]

Obtains the character set for the current locale; you might use this character set as an argument to g_convert(), to convert from the current locale's encoding to some other encoding.

(Frequently g_locale_to_utf8() and g_locale_from_utf8() are nice shortcuts, though.) The return value is TRUE if the locale's encoding is UTF-8, in that case you can perhaps avoid calling g_convert(). The string returned in charset is not allocated, and should not be freed. charset: return location for character set name Returns: TRUE if the returned charset is UTF-8 [1] Note that some encodings may allow nul bytes to occur inside strings. In that case, using -1 for the len parameter is unsafe. [2] Despite the fact that byes_read can return information about partial characters, the g_convert_... functions are not generally suitable for streaming. If the underlying converter being used maintains internal state, then this won't be preserved across successive calls to g_convert(), g_convert_with_iconv() or g_convert_with_fallback(). (An example of this is the GNU C converter for CP1255 which does not emit a base character until it knows that the next character is not a mark that could combine with the base character.)

static int glib.CharacterSet.CharacterSet.getFilenameCharsets ( char ***  charsets  )  [static]

Determines the preferred character sets used for filenames.

The first character set from the charsets is the filename encoding, the subsequent character sets are used when trying to generate a displayable representation of a filename, see g_filename_display_name(). On Unix, the character sets are determined by consulting the environment variables G_FILENAME_ENCODING and G_BROKEN_FILENAMES. On Windows, the character set used in the GLib API is always UTF-8 and said environment variables have no effect. G_FILENAME_ENCODING may be set to a comma-separated list of character set names. The special token "@locale" is taken to mean the character set for the current locale. If G_FILENAME_ENCODING is not set, but G_BROKEN_FILENAMES is, the character set of the current locale is taken as the filename encoding. If neither environment variable is set, UTF-8 is taken as the filename encoding, but the character set of the current locale is also put in the list of encodings. The returned charsets belong to GLib and must not be freed. Note that on Unix, regardless of the locale character set or G_FILENAME_ENCODING value, the actual file names present on a system might be in any random encoding or just gibberish. charsets: return location for the NULL-terminated list of encoding names Returns: TRUE if the filename encoding is UTF-8. Since 2.6

static char [] glib.CharacterSet.CharacterSet.localeFromUtf8 ( char[]  utf8string,
int  len,
uint bytesRead,
uint bytesWritten,
GError **  error 
) [static]

Converts a string from UTF-8 to the encoding used for strings by the C runtime (usually the same as that used by the operating system) in the current locale.

utf8string: a UTF-8 encoded string len: the length of the string, or -1 if the string is nul-terminated[1]. bytes_read: location to store the number of bytes in the input string that were successfully converted, or NULL. Even if the conversion was successful, this may be less than len if there were partial characters at the end of the input. If the error G_CONVERT_ERROR_ILLEGAL_SEQUENCE occurs, the value stored will the byte offset after the last valid input sequence. bytes_written: the number of bytes stored in the output buffer (not including the terminating nul). error: location to store the error occuring, or NULL to ignore errors. Any of the errors in GConvertError may occur. Returns: The converted string, or NULL on an error.

static char [] glib.CharacterSet.CharacterSet.localeToUtf8 ( char[]  opsysstring,
int  len,
uint bytesRead,
uint bytesWritten,
GError **  error 
) [static]

Converts a string which is in the encoding used for strings by the C runtime (usually the same as that used by the operating system) in the current locale into a UTF-8 string.

opsysstring: a string in the encoding of the current locale. On Windows this means the system codepage. len: the length of the string, or -1 if the string is nul-terminated[1]. bytes_read: location to store the number of bytes in the input string that were successfully converted, or NULL. Even if the conversion was successful, this may be less than len if there were partial characters at the end of the input. If the error G_CONVERT_ERROR_ILLEGAL_SEQUENCE occurs, the value stored will the byte offset after the last valid input sequence. bytes_written: the number of bytes stored in the output buffer (not including the terminating nul). error: location to store the error occuring, or NULL to ignore errors. Any of the errors in GConvertError may occur. Returns: The converted string, or NULL on an error.

static char** glib.CharacterSet.CharacterSet.uriListExtractUris ( char[]  uriList  )  [static]

Splits an URI list conforming to the text/uri-list mime type defined in RFC 2483 into individual URIs, discarding any comments.

The URIs are not validated. uri_list: an URI list Returns: a newly allocated NULL-terminated list of strings holding the individual URIs. The array should be freed with g_strfreev(). Since 2.6


SourceForge.net Logo DSource.org Logo digitalmars.com Logo