stdio/FreeBSD/fgetws.3

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  32 .\"     @(#)fgets.3     8.1 (Berkeley) 6/4/93
  33 .\" FreeBSD: src/lib/libc/stdio/fgets.3,v 1.16 2002/05/31 05:01:17 archie Exp
  34 .\" $FreeBSD: src/lib/libc/stdio/fgetws.3,v 1.4 2007/01/09 00:28:06 imp Exp $
  35 .\"
  36 .Dd August 6, 2002
  37 .Dt FGETWS 3
  38 .Os
  39 .Sh NAME
  40 .Nm fgetws
  41 .Nd get a line of wide characters from a stream
  42 .Sh LIBRARY
  43 .Lb libc
  44 .Sh SYNOPSIS
  45 .In stdio.h
  46 .In wchar.h
  47 .Ft "wchar_t *"
  48 .Fn fgetws "wchar_t * restrict ws" "int n" "FILE * restrict fp"
  49 .Sh DESCRIPTION
  50 The
  51 .Fn fgetws
  52 function
  53 reads at most one less than the number of characters specified by
  54 .Fa n
  55 from the given
  56 .Fa fp
  57 and stores them in the wide character string
  58 .Fa ws .
  59 Reading stops when a newline character is found,
  60 at end-of-file or error.
  61 The newline, if any, is retained.
  62 If any characters are read and there is no error, a
  63 .Ql \e0
  64 character is appended to end the string.
  65 .Sh RETURN VALUES
  66 Upon successful completion,
  67 .Fn fgetws
  68 returns
  69 .Fa ws .
  70 If end-of-file occurs before any characters are read,
  71 .Fn fgetws
  72 returns
  73 .Dv NULL
  74 and the buffer contents remain unchanged.
  75 If an error occurs,
  76 .Fn fgetws
  77 returns
  78 .Dv NULL
  79 and the buffer contents are indeterminate.
  80 The
  81 .Fn fgetws
  82 function
  83 does not distinguish between end-of-file and error, and callers must use
  84 .Xr feof 3
  85 and
  86 .Xr ferror 3
  87 to determine which occurred.
  88 .Sh ERRORS
  89 The
  90 .Fn fgetws
  91 function will fail if:
  92 .Bl -tag -width Er
  93 .It Bq Er EBADF
  94 The given
  95 .Fa fp
  96 argument is not a readable stream.
  97 .It Bq Er EILSEQ
  98 The data obtained from the input stream does not form a valid
  99 multibyte character.
 100 .El
 101 .Pp
 102 The function
 103 .Fn fgetws
 104 may also fail and set
 105 .Va errno
 106 for any of the errors specified for the routines
 107 .Xr fflush 3 ,
 108 .Xr fstat 2 ,
 109 .Xr read 2 ,
 110 or
 111 .Xr malloc 3 .
 112 .Sh SEE ALSO
 113 .Xr feof 3 ,
 114 .Xr ferror 3 ,
 115 .Xr fgets 3
 116 .Sh STANDARDS
 117 The
 118 .Fn fgetws
 119 function
 120 conforms to
 121 .St -p1003.1-2001 .