Extended maintenance of Ruby versions 1.8.7 and 1.9.2 ended on July 31, 2014. Read more

In Files

  • encoding.c
  • transcode.c

Encoding

Public Class Methods

aliases → {"alias1" => "orig1", "alias2" => "orig2", ...} click to toggle source

Returns the hash of available encoding alias and original encoding name.

Encoding.aliases
#=> {"BINARY"=>"ASCII-8BIT", "ASCII"=>"US-ASCII", "ANSI_X3.4-1986"=>"US-ASCII",
      "SJIS"=>"Shift_JIS", "eucJP"=>"EUC-JP", "CP932"=>"Windows-31J"}
 
               static VALUE
rb_enc_aliases(VALUE klass)
{
    VALUE aliases[2];
    aliases[0] = rb_hash_new();
    aliases[1] = rb_ary_new();
    st_foreach(enc_table.names, rb_enc_aliases_enc_i, (st_data_t)aliases);
    return aliases[0];
}
            
compatible?(str1, str2) → enc or nil click to toggle source

Checks the compatibility of two strings. If they are compatible, means concatenatable, returns an encoding which the concatenated string will be. If they are not compatible, nil is returned.

Encoding.compatible?("\xa1".force_encoding("iso-8859-1"), "b")
#=> #<Encoding:ISO-8859-1>

Encoding.compatible?(
  "\xa1".force_encoding("iso-8859-1"),
  "\xa1\xa1".force_encoding("euc-jp"))
#=> nil
 
               static VALUE
enc_compatible_p(VALUE klass, VALUE str1, VALUE str2)
{
    rb_encoding *enc;

    if (!enc_capable(str1)) return Qnil;
    if (!enc_capable(str2)) return Qnil;
    enc = rb_enc_compatible(str1, str2);
    if (!enc) return Qnil;
    return rb_enc_from_encoding(enc);
}
            
default_external → enc click to toggle source

Returns default external encoding.

It is initialized by the locale or -E option.

 
               static VALUE
get_default_external(VALUE klass)
{
    return rb_enc_default_external();
}
            
default_external = enc click to toggle source

Sets default external encoding.

 
               static VALUE
set_default_external(VALUE klass, VALUE encoding)
{
    rb_warning("setting Encoding.default_external");
    rb_enc_set_default_external(encoding);
    return encoding;
}
            
default_internal → enc click to toggle source

Returns default internal encoding.

It is initialized by the source internal_encoding or -E option.

 
               static VALUE
get_default_internal(VALUE klass)
{
    return rb_enc_default_internal();
}
            
default_internal = enc or nil click to toggle source

Sets default internal encoding. Or removes default internal encoding when passed nil.

 
               static VALUE
set_default_internal(VALUE klass, VALUE encoding)
{
    rb_warning("setting Encoding.default_internal");
    rb_enc_set_default_internal(encoding);
    return encoding;
}
            
find(string) → enc click to toggle source
find(symbol) → enc

Search the encoding with specified name. name should be a string or symbol.

Encoding.find("US-ASCII")  #=> #<Encoding:US-ASCII>
Encoding.find(:Shift_JIS)  #=> #<Encoding:Shift_JIS>

Names which this method accept are encoding names and aliases including following special aliases

“external”

default external encoding

“internal”

default internal encoding

“locale”

locale encoding

“filesystem”

filesystem encoding

An ArgumentError is raised when no encoding with name. Only Encoding.find("internal") however returns nil when no encoding named “internal”, in other words, when Ruby has no default internal encoding.

 
               static VALUE
enc_find(VALUE klass, VALUE enc)
{
    return rb_enc_from_encoding(to_encoding(enc));
}
            
list → [enc1, enc2, ...] click to toggle source

Returns the list of loaded encodings.

Encoding.list
#=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>,
      #<Encoding:ISO-2022-JP (dummy)>]

Encoding.find("US-ASCII")
#=> #<Encoding:US-ASCII>

Encoding.list
#=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>,
      #<Encoding:US-ASCII>, #<Encoding:ISO-2022-JP (dummy)>]
 
               static VALUE
enc_list(VALUE klass)
{
    VALUE ary = rb_ary_new2(0);
    rb_ary_replace(ary, rb_encoding_list);
    return ary;
}
            
locale_charmap → string click to toggle source

Returns the locale charmap name.

Debian GNU/Linux
  LANG=C
    Encoding.locale_charmap  #=> "ANSI_X3.4-1968"
  LANG=ja_JP.EUC-JP
    Encoding.locale_charmap  #=> "EUC-JP"

SunOS 5
  LANG=C
    Encoding.locale_charmap  #=> "646"
  LANG=ja
    Encoding.locale_charmap  #=> "eucJP"

The result is highly platform dependent. So ::find may cause an error. If you need some encoding object even for unknown locale, ::find(“locale”) can be used.

 
               VALUE
rb_locale_charmap(VALUE klass)
{
#if defined NO_LOCALE_CHARMAP
    return rb_usascii_str_new2("ASCII-8BIT");
#elif defined _WIN32 || defined __CYGWIN__
    const char *nl_langinfo_codeset(void);
    const char *codeset = nl_langinfo_codeset();
    char cp[sizeof(int) * 3 + 4];
    if (!codeset) {
        snprintf(cp, sizeof(cp), "CP%d", GetConsoleCP());
        codeset = cp;
    }
    return rb_usascii_str_new2(codeset);
#elif defined HAVE_LANGINFO_H
    char *codeset;
    codeset = nl_langinfo(CODESET);
    return rb_usascii_str_new2(codeset);
#else
    return Qnil;
#endif
}
            
name_list → ["enc1", "enc2", ...] click to toggle source

Returns the list of available encoding names.

Encoding.name_list
#=> ["US-ASCII", "ASCII-8BIT", "UTF-8",
      "ISO-8859-1", "Shift_JIS", "EUC-JP",
      "Windows-31J",
      "BINARY", "CP932", "eucJP"]
 
               static VALUE
rb_enc_name_list(VALUE klass)
{
    VALUE ary = rb_ary_new2(enc_table.names->num_entries);
    st_foreach(enc_table.names, rb_enc_name_list_i, (st_data_t)ary);
    return ary;
}
            

Public Instance Methods

ascii_compatible? → true or false click to toggle source

Returns whether ASCII-compatible or not.

Encoding::UTF_8.ascii_compatible?     #=> true
Encoding::UTF_16BE.ascii_compatible?  #=> false
 
               static VALUE
enc_ascii_compatible_p(VALUE enc)
{
    return rb_enc_asciicompat(enc_table.list[must_encoding(enc)].enc) ? Qtrue : Qfalse;
}
            
dummy? → true or false click to toggle source

Returns true for dummy encodings. A dummy encoding is an encoding for which character handling is not properly implemented. It is used for stateful encodings.

Encoding::ISO_2022_JP.dummy?       #=> true
Encoding::UTF_8.dummy?             #=> false
 
               static VALUE
enc_dummy_p(VALUE enc)
{
    return ENC_DUMMY_P(enc_table.list[must_encoding(enc)].enc) ? Qtrue : Qfalse;
}
            
inspect → string click to toggle source

Returns a string which represents the encoding for programmers.

Encoding::UTF_8.inspect       #=> "#<Encoding:UTF-8>"
Encoding::ISO_2022_JP.inspect #=> "#<Encoding:ISO-2022-JP (dummy)>"
 
               static VALUE
enc_inspect(VALUE self)
{
    VALUE str = rb_sprintf("#<%s:%s%s>", rb_obj_classname(self),
                      rb_enc_name((rb_encoding*)DATA_PTR(self)),
                      (enc_dummy_p(self) ? " (dummy)" : ""));
    ENCODING_CODERANGE_SET(str, rb_usascii_encindex(), ENC_CODERANGE_7BIT);
    return str;
}
            
name → string click to toggle source

Returns the name of the encoding.

Encoding::UTF_8.name      #=> "UTF-8"
 
               static VALUE
enc_name(VALUE self)
{
    return rb_usascii_str_new2(rb_enc_name((rb_encoding*)DATA_PTR(self)));
}
            
names → array click to toggle source

Returns the list of name and aliases of the encoding.

Encoding::WINDOWS_31J.names  #=> ["Windows-31J", "CP932", "csWindows31J"]
 
               static VALUE
enc_names(VALUE self)
{
    VALUE args[2];

    args[0] = (VALUE)rb_to_encoding_index(self);
    args[1] = rb_ary_new2(0);
    st_foreach(enc_table.names, enc_names_i, (st_data_t)args);
    return args[1];
}
            
replicate(name) → encoding click to toggle source

Returns a replicated encoding of enc whose name is name. The new encoding should have the same byte structure of enc. If name is used by another encoding, raise ArgumentError.

 
               static VALUE
enc_replicate(VALUE encoding, VALUE name)
{
    return rb_enc_from_encoding_index(
        rb_enc_replicate(StringValueCStr(name),
                         rb_to_encoding(encoding)));
}
            
name → string click to toggle source

Returns the name of the encoding.

Encoding::UTF_8.name      #=> "UTF-8"
 
               static VALUE
enc_name(VALUE self)
{
    return rb_usascii_str_new2(rb_enc_name((rb_encoding*)DATA_PTR(self)));
}
            

Commenting is here to help enhance the documentation. For example, code samples, or clarification of the documentation.

If you have questions about Ruby or the documentation, please post to one of the Ruby mailing lists. You will get better, faster, help that way.

If you wish to post a correction of the docs, please do so, but also file bug report so that it can be corrected for the next release. Thank you.

If you want to help improve the Ruby documentation, please visit Documenting-ruby.org.

blog comments powered by Disqus