.\" Copyright (C) 2001 Information-technology Promotion Agency (IPA) .\" Copyright (C) 2001-2003 .\" National Institute of Advanced Industrial Science and Technology (AIST) .\" This file si aprt of the m17n library documentation. .\" Permission is granted to copy, distribute and/or modify this document .\" under the terms of the GNU Free Documentation License, Version 1.2 or .\" any later version published by the Free Software Foundation; with no .\" Invariant Section, Front-Cover Texts "The m17n library documentation", .\" and no Back-Cover Texts. A copy of the license is included in the .\" appendix entitled "GNU Free Documentation License". .TH "Code Conversion" 3m17n "14 Jul 2007" "" "Version 1.4.0" "" "The m17n Library" \" -*- nroff -*- .ad l .nh .SH NAME Code Conversion \- Coding system objects and API for them. .PP .SS "Data Structures" .in +1c .ti -1c .RI "struct \fBMConverter\fP" .br .RI "\fIStructure to be used in code conversion. \fP" .ti -1c .RI "struct \fBMCodingInfoISO2022\fP" .br .RI "\fIStructure for a coding system of type \fBMCODING_TYPE_ISO_2022\fP. \fP" .ti -1c .RI "struct \fBMCodingInfoUTF\fP" .br .RI "\fIStructure for extra information about a coding system of type \fBMCODING_TYPE_UTF\fP. \fP" .in -1c .SS "Variables: Symbols representing coding systems" .in +1c .ti -1c .RI "\fBMSymbol\fP \fBMcoding_us_ascii\fP" .br .RI "\fISymbol for the coding system US-ASCII. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_iso_8859_1\fP" .br .RI "\fISymbol for the coding system ISO-8859-1. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_utf_8\fP" .br .RI "\fISymbol for the coding system UTF-8. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_utf_8_full\fP" .br .RI "\fISymbol for the coding system UTF-8-FULL. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_utf_16\fP" .br .RI "\fISymbol for the coding system UTF-16. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_utf_16be\fP" .br .RI "\fISymbol for the coding system UTF-16BE. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_utf_16le\fP" .br .RI "\fISymbol for the coding system UTF-16LE. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_utf_32\fP" .br .RI "\fISymbol for the coding system UTF-32. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_utf_32be\fP" .br .RI "\fISymbol for the coding system UTF-32BE. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_utf_32le\fP" .br .RI "\fISymbol for the coding system UTF-32LE. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding_sjis\fP" .br .RI "\fISymbol for the coding system SJIS. \fP" .in -1c .SS "Variables: Parameter keys for mconv_define_coding()." .in +1c .ti -1c .RI "\fBMSymbol\fP \fBMtype\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMcharsets\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMflags\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMdesignation\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMinvocation\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMcode_unit\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMbom\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMlittle_endian\fP" .br .in -1c .SS "Variables: Symbols representing coding system types." .in +1c .ti -1c .RI "\fBMSymbol\fP \fBMutf\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMiso_2022\fP" .br .in -1c .SS "Variables: Symbols appearing in the value of #Mflags parameter." .in +1c .ti -1c .RI "\fBMSymbol\fP \fBMreset_at_eol\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMreset_at_cntl\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMeight_bit\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMlong_form\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMdesignation_g0\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMdesignation_g1\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMdesignation_ctext\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMdesignation_ctext_ext\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMlocking_shift\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMsingle_shift\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMsingle_shift_7\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMeuc_tw_shift\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMiso_6429\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMrevision_number\fP" .br .ti -1c .RI "\fBMSymbol\fP \fBMfull_support\fP" .br .in -1c .SS "Variables: etc" Remaining variables. .in +1c .ti -1c .RI "\fBMSymbol\fP \fBMmaybe\fP" .br .RI "\fISymbol whose name is 'maybe'. \fP" .ti -1c .RI "\fBMSymbol\fP \fBMcoding\fP" .br .RI "\fIThe symbol \fCMcoding\fP. \fP" .in -1c .SS "Enumerations" .in +1c .ti -1c .RI "enum \fBMConversionResult\fP { \fBMCONVERSION_RESULT_SUCCESS\fP, \fBMCONVERSION_RESULT_INVALID_BYTE\fP, \fBMCONVERSION_RESULT_INVALID_CHAR\fP, \fBMCONVERSION_RESULT_INSUFFICIENT_SRC\fP, \fBMCONVERSION_RESULT_INSUFFICIENT_DST\fP, \fBMCONVERSION_RESULT_IO_ERROR\fP }" .br .RI "\fICodes that represent the result of code conversion. \fP" .ti -1c .RI "enum \fBMCodingType\fP { \fBMCODING_TYPE_CHARSET\fP, \fBMCODING_TYPE_UTF\fP, \fBMCODING_TYPE_ISO_2022\fP, \fBMCODING_TYPE_MISC\fP }" .br .RI "\fITypes of coding system. \fP" .ti -1c .RI "enum \fBMCodingFlagISO2022\fP { \fBMCODING_ISO_RESET_AT_EOL\fP = 0x1, \fBMCODING_ISO_RESET_AT_CNTL\fP = 0x2, \fBMCODING_ISO_EIGHT_BIT\fP = 0x4, \fBMCODING_ISO_LONG_FORM\fP = 0x8, \fBMCODING_ISO_DESIGNATION_G0\fP = 0x10, \fBMCODING_ISO_DESIGNATION_G1\fP = 0x20, \fBMCODING_ISO_DESIGNATION_CTEXT\fP = 0x40, \fBMCODING_ISO_DESIGNATION_CTEXT_EXT\fP = 0x80, \fBMCODING_ISO_LOCKING_SHIFT\fP = 0x100, \fBMCODING_ISO_SINGLE_SHIFT\fP = 0x200, \fBMCODING_ISO_SINGLE_SHIFT_7\fP = 0x400, \fBMCODING_ISO_EUC_TW_SHIFT\fP = 0x800, \fBMCODING_ISO_ISO6429\fP = 0x1000, \fBMCODING_ISO_REVISION_NUMBER\fP = 0x2000, \fBMCODING_ISO_FULL_SUPPORT\fP = 0x3000, \fBMCODING_ISO_FLAG_MAX\fP }" .br .RI "\fIBit-masks to specify the detail of coding system whose type is MCODING_TYPE_ISO_2022. \fP" .in -1c .SS "Functions" .in +1c .ti -1c .RI "\fBMSymbol\fP \fBmconv_define_coding\fP (const char *name, \fBMPlist\fP *plist, int(*resetter)(\fBMConverter\fP *), int(*decoder)(const unsigned char *, int, \fBMText\fP *, \fBMConverter\fP *), int(*encoder)(\fBMText\fP *, int, int, unsigned char *, int, \fBMConverter\fP *), void *extra_info)" .br .RI "\fIDefine a coding system. \fP" .ti -1c .RI "\fBMSymbol\fP \fBmconv_resolve_coding\fP (\fBMSymbol\fP symbol)" .br .RI "\fIResolve coding system name. \fP" .ti -1c .RI "int \fBmconv_list_codings\fP (\fBMSymbol\fP **symbols)" .br .RI "\fIList symbols representing coding systems. \fP" .ti -1c .RI "\fBMConverter\fP * \fBmconv_buffer_converter\fP (\fBMSymbol\fP name, const unsigned char *buf, int n)" .br .RI "\fICreate a code converter bound to a buffer. \fP" .ti -1c .RI "\fBMConverter\fP * \fBmconv_stream_converter\fP (\fBMSymbol\fP name, FILE *fp)" .br .RI "\fICreate a code converter bound to a stream. \fP" .ti -1c .RI "int \fBmconv_reset_converter\fP (\fBMConverter\fP *converter)" .br .RI "\fIReset a code converter. \fP" .ti -1c .RI "void \fBmconv_free_converter\fP (\fBMConverter\fP *converter)" .br .RI "\fIFree a code converter. \fP" .ti -1c .RI "\fBMConverter\fP * \fBmconv_rebind_buffer\fP (\fBMConverter\fP *converter, const unsigned char *buf, int n)" .br .RI "\fIBind a buffer to a code converter. \fP" .ti -1c .RI "\fBMConverter\fP * \fBmconv_rebind_stream\fP (\fBMConverter\fP *converter, FILE *fp)" .br .RI "\fIBind a stream to a code converter. \fP" .ti -1c .RI "\fBMText\fP * \fBmconv_decode\fP (\fBMConverter\fP *converter, \fBMText\fP *mt)" .br .RI "\fIDecode a byte sequence into an M-text. \fP" .ti -1c .RI "\fBMText\fP * \fBmconv_decode_buffer\fP (\fBMSymbol\fP name, const unsigned char *buf, int n)" .br .RI "\fIDecode a buffer area based on a coding system. \fP" .ti -1c .RI "\fBMText\fP * \fBmconv_decode_stream\fP (\fBMSymbol\fP name, FILE *fp)" .br .RI "\fIDecode a stream input based on a coding system. \fP" .ti -1c .RI "int \fBmconv_encode\fP (\fBMConverter\fP *converter, \fBMText\fP *mt)" .br .RI "\fIEncode an M-text into a byte sequence. \fP" .ti -1c .RI "int \fBmconv_encode_range\fP (\fBMConverter\fP *converter, \fBMText\fP *mt, int from, int to)" .br .RI "\fIEncode a part of an M-text. \fP" .ti -1c .RI "int \fBmconv_encode_buffer\fP (\fBMSymbol\fP name, \fBMText\fP *mt, unsigned char *buf, int n)" .br .RI "\fIEncode an M-text into a buffer area. \fP" .ti -1c .RI "int \fBmconv_encode_stream\fP (\fBMSymbol\fP name, \fBMText\fP *mt, FILE *fp)" .br .RI "\fIEncode an M-text to write to a stream. \fP" .ti -1c .RI "int \fBmconv_getc\fP (\fBMConverter\fP *converter)" .br .RI "\fIRead a character via a code converter. \fP" .ti -1c .RI "int \fBmconv_ungetc\fP (\fBMConverter\fP *converter, int c)" .br .RI "\fIPush a character back to a code converter. \fP" .ti -1c .RI "int \fBmconv_putc\fP (\fBMConverter\fP *converter, int c)" .br .RI "\fIWrite a character via a code converter. \fP" .ti -1c .RI "\fBMText\fP * \fBmconv_gets\fP (\fBMConverter\fP *converter, \fBMText\fP *mt)" .br .RI "\fIRead a line using a code converter. \fP" .in -1c .SH "Detailed Description" .PP The m17n library represents a character encoding scheme (CES) of coded character sets (CCS) as an object called \fIcoding\fP \fIsystem\fP. Application programs can add original coding systems. .PP To \fIencode\fP means converting code-points to character codes and to \fIdecode\fP means converting character codes back to code-points. .PP Application programs can decode a byte sequence with a specified coding system into an M-text, and inversely, can encode an M-text into a byte sequence. .SH "Data Structure Documentation" .SS MConverter .PP Structure to be used in code conversion. .PP .ad l .nh .PP \fBFIELD DOCUMENTATION:\fP .PP .PP \fBint \fBMConverter::lenient\fP\fP .PP Set the value to nonzero if the conversion should be lenient. By default, the conversion is strict (i.e. not lenient). .PP If the conversion is strict, the converter stops at the first invalid byte (on decoding) or at the first character not supported by the coding system (on encoding). If this happens, \fCMConverter->result\fP is set to \fCMCONVERSION_RESULT_INVALID_BYTE\fP or \fCMCONVERSION_RESULT_INVALID_CHAR\fP accordingly. .PP If the conversion is lenient, on decoding, an invalid byte is kept per se, and on encoding, an invalid character is replaced with '' (if the character is a Unicode character) or with '' (otherwise). .PP \fBint \fBMConverter::last_block\fP\fP .PP Set the value to nonzero before decoding or encoding the last block of the byte sequence or the character sequence respectively. The value influences the conversion as below. .PP On decoding, in the case that the last few bytes are too short to form a valid byte sequence: .PP If the value is nonzero, the conversion terminates by error (MCONVERSION_RESULT_INVALID_BYTE) at the first byte of the sequence. .PP If the value is zero, the conversion terminates successfully. Those bytes are stored in the converter as carryover and are prepended to the byte sequence of the further conversion. .PP On encoding, in the case that the coding system is context dependent: .PP If the value is nonzero, the conversion may produce a byte sequence at the end to reset the context to the initial state even if the source characters are zero. .PP If the value is zero, the conversion never produce such a byte sequence at the end. .PP \fBunsigned \fBMConverter::at_most\fP\fP .PP If the value is nonzero, it specifies at most how many characters to convert. .PP \fBint \fBMConverter::nchars\fP\fP .PP The following three members are to report the result of the conversion. .PP Number of characters most recently decoded or encoded. .PP \fBint \fBMConverter::nbytes\fP\fP .PP Number of bytes recently decoded or encoded. .PP \fBenum \fBMConversionResult\fP \fBMConverter::result\fP\fP .PP Result code of the conversion. .PP \fBvoid* \fBMConverter::ptr\fP\fP .PP .PP \fBdouble \fBMConverter::dbl\fP\fP .PP .PP \fBchar \fBMConverter::c\fP[256]\fP .PP .PP \fBunion { ... } \fBMConverter::status\fP\fP .PP Various information about the status of code conversion. The contents depend on the type of coding system. It is assured that \fCstatus\fP is aligned so that any type of casting is safe and at least 256 bytes of memory space can be used. .PP \fBvoid* \fBMConverter::internal_info\fP\fP .PP This member is for internally use only. An application program should never touch it. .SS MCodingInfoISO2022 .PP Structure for a coding system of type \fBMCODING_TYPE_ISO_2022\fP. .PP .ad l .nh .PP \fBFIELD DOCUMENTATION:\fP .PP .PP \fBint \fBMCodingInfoISO2022::initial_invocation\fP[2]\fP .PP Table of numbers of an ISO2022 code extension element invoked to each graphic plane (Graphic Left and Graphic Right). -1 means no code extension element is invoked to that plane. .PP \fBchar \fBMCodingInfoISO2022::designations\fP[32]\fP .PP Table of code extension elements. The Nth element corresponds to the Nth charset in \fBcharset_names\fP, which is an argument given to the \fBmconv_define_coding()\fP function. .PP If an element value is 0..3, it specifies a graphic register number to designate the corresponds charset. In addition, the charset is initially designated to that graphic register. .PP If the value is -4..-1, it specifies a graphic register number 0..3 respectively to designate the corresponds charset. Initially, the charset is not designated to any graphic register. .PP \fBunsigned \fBMCodingInfoISO2022::flags\fP\fP .PP Bitwise OR of \fCenum\fP \fCMCodingFlagISO2022\fP . .SS MCodingInfoUTF .PP Structure for extra information about a coding system of type \fBMCODING_TYPE_UTF\fP. .PP .ad l .nh .PP \fBFIELD DOCUMENTATION:\fP .PP .PP \fBint \fBMCodingInfoUTF::code_unit_bits\fP\fP .PP Specify bits of a code unit. The value must be 8, 16, or 32. .PP \fBint \fBMCodingInfoUTF::bom\fP\fP .PP Specify how to handle the heading BOM (byte order mark). The value must be 0, 1, or 2. The meanings are as follows: .PP 0: On decoding, check the first two byte. If they are BOM, decide endian by them. If not, decide endian by the member \fCendian\fP. On encoding, produce byte sequence according to \fCendian\fP with heading BOM. .PP 1: On decoding, do not handle the first two bytes as BOM, and decide endian by \fCendian\fP. On encoding, produce byte sequence according to \fCendian\fP without BOM. .PP 2: On decoding, handle the first two bytes as BOM and decide ending by them. On encoding, produce byte sequence according to \fCendian\fP with heading BOM. .PP If is 8, the value has no meaning. .PP \fBint \fBMCodingInfoUTF::endian\fP\fP .PP Specify the endian type. The value must be 0 or 1. 0 means little endian, and 1 means big endian. .PP If is 8, the value has no meaning. .SH "Enumeration Type Documentation" .PP .SS "enum \fBMConversionResult\fP" .PP One of these values is set in \fCMConverter->result\fP. .PP \fBEnumerator: \fP .in +1c .TP \fB\fIMCONVERSION_RESULT_SUCCESS \fP\fP .TP \fB\fIMCONVERSION_RESULT_INVALID_BYTE \fP\fP .TP \fB\fIMCONVERSION_RESULT_INVALID_CHAR \fP\fP .TP \fB\fIMCONVERSION_RESULT_INSUFFICIENT_SRC \fP\fP .TP \fB\fIMCONVERSION_RESULT_INSUFFICIENT_DST \fP\fP .TP \fB\fIMCONVERSION_RESULT_IO_ERROR \fP\fP .SS "enum \fBMCodingType\fP" .PP \fBEnumerator: \fP .in +1c .TP \fB\fIMCODING_TYPE_CHARSET \fP\fP .PP The m17n library provides the default decoding and encoding routines of this type. .TP \fB\fIMCODING_TYPE_UTF \fP\fP .PP The m17n library provides the default decoding and encoding routines of this type. .TP \fB\fIMCODING_TYPE_ISO_2022 \fP\fP .PP The m17n library provides decoding and encoding routines of this type. .TP \fB\fIMCODING_TYPE_MISC \fP\fP .PP The m17n library does not provide decoding and encoding routines of this type. They must be provided by the application program. .SS "enum \fBMCodingFlagISO2022\fP" .PP \fBEnumerator: \fP .in +1c .TP \fB\fIMCODING_ISO_RESET_AT_EOL \fP\fP .TP \fB\fIMCODING_ISO_RESET_AT_CNTL \fP\fP .TP \fB\fIMCODING_ISO_EIGHT_BIT \fP\fP .TP \fB\fIMCODING_ISO_LONG_FORM \fP\fP .TP \fB\fIMCODING_ISO_DESIGNATION_G0 \fP\fP .TP \fB\fIMCODING_ISO_DESIGNATION_G1 \fP\fP .TP \fB\fIMCODING_ISO_DESIGNATION_CTEXT \fP\fP .TP \fB\fIMCODING_ISO_DESIGNATION_CTEXT_EXT \fP\fP .TP \fB\fIMCODING_ISO_LOCKING_SHIFT \fP\fP .TP \fB\fIMCODING_ISO_SINGLE_SHIFT \fP\fP .TP \fB\fIMCODING_ISO_SINGLE_SHIFT_7 \fP\fP .TP \fB\fIMCODING_ISO_EUC_TW_SHIFT \fP\fP .TP \fB\fIMCODING_ISO_ISO6429 \fP\fP .TP \fB\fIMCODING_ISO_REVISION_NUMBER \fP\fP .TP \fB\fIMCODING_ISO_FULL_SUPPORT \fP\fP .TP \fB\fIMCODING_ISO_FLAG_MAX \fP\fP .SH "Variable Documentation" .PP .SS "\fBMSymbol\fP \fBMcoding_us_ascii\fP" .PP The symbol \fBMcoding_us_ascii\fP has name \fC'us-ascii'\fP and represents a coding system for the CES US-ASCII. .SS "\fBMSymbol\fP \fBMcoding_iso_8859_1\fP" .PP The symbol \fBMcoding_iso_8859_1\fP has name \fC'iso-8859-1'\fP and represents a coding system for the CES ISO-8859-1. .SS "\fBMSymbol\fP \fBMcoding_utf_8\fP" .PP The symbol \fBMcoding_utf_8\fP has name \fC'utf-8'\fP and represents a coding system for the CES UTF-8. .SS "\fBMSymbol\fP \fBMcoding_utf_8_full\fP" .PP The symbol \fBMcoding_utf_8_full\fP has name \fC'utf-8-full'\fP and represents a coding system that is a extension of UTF-8. This coding system uses the same encoding algorithm as UTF-8 but is not limited to the Unicode characters. It can encode all characters supported by the m17n library. .SS "\fBMSymbol\fP \fBMcoding_utf_16\fP" .PP The symbol \fBMcoding_utf_16\fP has name \fC'utf-16'\fP and represents a coding system for the CES UTF-16 (RFC 2279). .SS "\fBMSymbol\fP \fBMcoding_utf_16be\fP" .PP The symbol \fBMcoding_utf_16be\fP has name \fC'utf-16be'\fP and represents a coding system for the CES UTF-16BE (RFC 2279). .SS "\fBMSymbol\fP \fBMcoding_utf_16le\fP" .PP The symbol \fBMcoding_utf_16le\fP has name \fC'utf-16le'\fP and represents a coding system for the CES UTF-16LE (RFC 2279). .SS "\fBMSymbol\fP \fBMcoding_utf_32\fP" .PP The symbol \fBMcoding_utf_32\fP has name \fC'utf-32'\fP and represents a coding system for the CES UTF-32 (RFC 2279). .SS "\fBMSymbol\fP \fBMcoding_utf_32be\fP" .PP The symbol \fBMcoding_utf_32be\fP has name \fC'utf-32be'\fP and represents a coding system for the CES UTF-32BE (RFC 2279). .SS "\fBMSymbol\fP \fBMcoding_utf_32le\fP" .PP The symbol \fBMcoding_utf_32le\fP has name \fC'utf-32le'\fP and represents a coding system for the CES UTF-32LE (RFC 2279). .SS "\fBMSymbol\fP \fBMcoding_sjis\fP" .PP The symbol \fBMcoding_sjis\fP has name \fC'sjis'\fP and represents a coding system for the CES Shift-JIS. .SS "\fBMSymbol\fP \fBMtype\fP" .PP Parameter key for \fBmconv_define_coding()\fP (which see). .SS "\fBMSymbol\fP \fBMcharsets\fP" .PP Parameter key for \fBmconv_define_coding()\fP (which see). .SS "\fBMSymbol\fP \fBMflags\fP" .PP Parameter key for \fBmconv_define_coding()\fP (which see). .SS "\fBMSymbol\fP \fBMdesignation\fP" .PP Parameter key for \fBmconv_define_coding()\fP (which see). .SS "\fBMSymbol\fP \fBMinvocation\fP" .PP Parameter key for \fBmconv_define_coding()\fP (which see). .SS "\fBMSymbol\fP \fBMcode_unit\fP" .PP Parameter key for \fBmconv_define_coding()\fP (which see). .SS "\fBMSymbol\fP \fBMbom\fP" .PP Parameter key for \fBmconv_define_coding()\fP (which see). .SS "\fBMSymbol\fP \fBMlittle_endian\fP" .PP Parameter key for \fBmconv_define_coding()\fP (which see). .SS "\fBMSymbol\fP \fBMutf\fP" .PP Symbol that can be a value of the \fBMtype\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMiso_2022\fP" .PP Symbol that can be a value of the \fBMtype\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMreset_at_eol\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMreset_at_cntl\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMeight_bit\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMlong_form\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMdesignation_g0\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMdesignation_g1\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMdesignation_ctext\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMdesignation_ctext_ext\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMlocking_shift\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMsingle_shift\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMsingle_shift_7\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMeuc_tw_shift\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMiso_6429\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMrevision_number\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMfull_support\fP" .PP Symbols that can be a value of the \fBMflags\fP parameter of a coding system used in an argument to the \fBmconv_define_coding()\fP function (which see). .SS "\fBMSymbol\fP \fBMmaybe\fP" .PP The variable \fBMmaybe\fP is a symbol of name \fC'maybe'\fP. It is used a value of \fBMbom\fP parameter of the function \fBmconv_define_coding()\fP (which see). .SS "\fBMSymbol\fP \fBMcoding\fP" .PP Any decoded M-text has a text property whose key is the predefined symbol \fCMcoding\fP. The name of \fCMcoding\fP is \fC'coding'\fP.