locale/rune.3

   1 .\" Copyright (c) 1993
   2 .\"     The Regents of the University of California.  All rights reserved.
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   4 .\" This code is derived from software contributed to Berkeley by
   5 .\" Paul Borman at Krystal Technologies.
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  35 .\"     @(#)rune.3      8.2 (Berkeley) 12/11/93
  36 .\" $FreeBSD: src/lib/libc/locale/rune.3,v 1.22 2002/12/19 09:40:22 ru Exp $
  37 .\"
  38 .Dd October 6, 2002
  39 .Dt RUNE 3
  40 .Os
  41 .Sh NAME
  42 .Nm setrunelocale ,
  43 .Nm setinvalidrune ,
  44 .Nm sgetrune ,
  45 .Nm sputrune ,
  46 .Nm fgetrune ,
  47 .Nm fungetrune ,
  48 .Nm fputrune
  49 .Nd rune support for C
  50 .Sh LIBRARY
  51 .Lb libc
  52 .Sh SYNOPSIS
  53 .In rune.h
  54 .In errno.h
  55 .Ft int
  56 .Fn setrunelocale "char *locale"
  57 .Ft void
  58 .Fn setinvalidrune "rune_t rune"
  59 .Ft rune_t
  60 .Fn sgetrune "const char *string" "size_t n" "char const **result"
  61 .Ft int
  62 .Fn sputrune "rune_t rune" "char *string" "size_t n" "char **result"
  63 .Pp
  64 .In stdio.h
  65 .Ft long
  66 .Fn fgetrune "FILE *stream"
  67 .Ft int
  68 .Fn fungetrune "rune_t rune" "FILE *stream"
  69 .Ft int
  70 .Fn fputrune "rune_t rune" "FILE *stream"
  71 .Sh DESCRIPTION
  72 .Bf Em
  73 The
  74 .Bx 4.4
  75 .Dq rune
  76 functions have been deprecated in favour of the
  77 .Tn ISO
  78 C99 extended multibyte and wide character facilities
  79 and should not be used in new applications.
  80 .Ef
  81 Consider using
  82 .Xr setlocale 3 ,
  83 .Xr mbrtowc 3 ,
  84 .Xr wcrtomb 3 ,
  85 .Xr fgetwc 3 ,
  86 .Xr ungetwc 3 ,
  87 and
  88 .Xr fputwc 3
  89 instead.
  90 .Pp
  91 The
  92 .Fn setrunelocale
  93 controls the type of encoding used to represent runes as multibyte strings
  94 as well as the properties of the runes as defined in
  95 .Aq Pa ctype.h .
  96 The
  97 .Fa locale
  98 argument indicates which locale to load.
  99 If the locale is successfully loaded,
 100 .Dv 0
 101 is returned, otherwise an errno value is returned to indicate the
 102 type of error.
 103 .Pp
 104 The
 105 .Fn setinvalidrune
 106 function sets the value of the global value
 107 .Dv _INVALID_RUNE
 108 to be
 109 .Fa rune .
 110 .Pp
 111 The
 112 .Fn sgetrune
 113 function tries to read a single multibyte character from
 114 .Fa string ,
 115 which is at most
 116 .Fa n
 117 bytes long.
 118 If
 119 .Fn sgetrune
 120 is successful, the rune is returned.
 121 If
 122 .Fa result
 123 is not
 124 .Dv NULL ,
 125 .Fa *result
 126 will point to the first byte which was not converted in
 127 .Fa string .
 128 If the first
 129 .Fa n
 130 bytes of
 131 .Fa string
 132 do not describe a full multibyte character,
 133 .Dv _INVALID_RUNE
 134 is returned and
 135 .Fa *result
 136 will point to
 137 .Fa string .
 138 If there is an encoding error at the start of
 139 .Fa string ,
 140 .Dv _INVALID_RUNE
 141 is returned and
 142 .Fa *result
 143 will point to the second character of
 144 .Fa string .
 145 .Pp
 146 the
 147 .Fn sputrune
 148 function tries to encode
 149 .Fa rune
 150 as a multibyte string and store it at
 151 .Fa string ,
 152 but no more than
 153 .Fa n
 154 bytes will be stored.
 155 If
 156 .Fa result
 157 is not
 158 .Dv NULL ,
 159 .Fa *result
 160 will be set to point to the first byte in string following the new
 161 multibyte character.
 162 If
 163 .Fa string
 164 is
 165 .Dv NULL ,
 166 .Fa *result
 167 will point to
 168 .Dv "(char *)0 +"
 169 .Fa x ,
 170 where
 171 .Fa x
 172 is the number of bytes that would be needed to store the multibyte value.
 173 If the multibyte character would consist of more than
 174 .Fa n
 175 bytes and
 176 .Fa result
 177 is not
 178 .Dv NULL ,
 179 .Fa *result
 180 will be set to
 181 .Dv NULL .
 182 In all cases,
 183 .Fn sputrune
 184 will return the number of bytes which would be needed to store
 185 .Fa rune
 186 as a multibyte character.
 187 .Pp
 188 The
 189 .Fn fgetrune
 190 function operates the same as
 191 .Fn sgetrune
 192 with the exception that it attempts to read enough bytes from
 193 .Fa stream
 194 to decode a single rune.  It returns either
 195 .Dv EOF
 196 on end of file,
 197 .Dv _INVALID_RUNE
 198 on an encoding error, or the rune decoded if all went well.
 199 .Pp
 200 The
 201 .Fn fungetrune
 202 function pushes the multibyte encoding, as provided by
 203 .Fn sputrune ,
 204 of
 205 .Fa rune
 206 onto
 207 .Fa stream
 208 such that the next
 209 .Fn fgetrune
 210 call will return
 211 .Fa rune .
 212 It returns
 213 .Dv EOF
 214 if it fails and
 215 .Dv 0
 216 on success.
 217 .Pp
 218 The
 219 .Fn fputrune
 220 function writes the multibyte encoding of
 221 .Fa rune ,
 222 as provided by
 223 .Fn sputrune ,
 224 onto
 225 .Fa stream .
 226 It returns
 227 .Dv EOF
 228 on failure and
 229 .Dv 0
 230 on success.
 231 .Sh RETURN VALUES
 232 The
 233 .Fn setrunelocale
 234 function returns one of the following values:
 235 .Bl -tag -width Er
 236 .It Er 0
 237 The
 238 .Fn setrunelocale
 239 function
 240 was successful.
 241 .It Bq Er EINVAL
 242 The
 243 .Fa locale
 244 name was incorrect.
 245 .It Bq Er ENOENT
 246 The locale could not be found.
 247 .It Bq Er EFTYPE
 248 The file found was not a valid file.
 249 .El
 250 .Pp
 251 The
 252 .Fn sgetrune
 253 function either returns the rune read or
 254 .Dv _INVALID_RUNE .
 255 The
 256 .Fn sputrune
 257 function returns the number of bytes needed to store
 258 .Fa rune
 259 as a multibyte string.
 260 .Sh FILES
 261 .Bl -tag -width /usr/share/locale/locale/LC_CTYPE -compact
 262 .It Pa $PATH_LOCALE/ Ns Em locale Ns /LC_CTYPE
 263 .It Pa /usr/share/locale/ Ns Em locale Ns /LC_CTYPE
 264 binary LC_CTYPE file for the locale
 265 .Em locale .
 266 .El
 267 .Sh SEE ALSO
 268 .Xr mbrune 3 ,
 269 .Xr setlocale 3 ,
 270 .Xr euc 4 ,
 271 .Xr utf2 4 ,
 272 .Xr utf8 5
 273 .Sh HISTORY
 274 These functions first appeared in
 275 .Bx 4.4 .
 276 .Pp
 277 The
 278 .Fn setrunelocale
 279 function and the other non-ANSI rune functions were inspired by
 280 .Sy "Plan 9 from Bell Labs" .
 281 .\"They were conceived at the San Diego 1993 Summer USENIX conference by
 282 .\"Paul Borman of Krystal Technologies, Keith Bostic of CSRG and Andrew Hume
 283 .\"of Bell Labs.