NAME<\/a> fwide \u2212 set and determine the orientation of a FILE stream<\/p>\n #include int fwide(FILE *<\/b>stream<\/i>, int<\/b> mode<\/i>);<\/b><\/p>\n Feature Test Macro Requirements for glibc (see feature_test_macros<\/b>(7)):<\/p>\n fwide<\/b>():<\/p>\n _XOPEN_SOURCE\u00a0>=\u00a0500 || _ISOC99_SOURCE || When mode<\/i> is zero, the fwide<\/b>() function determines the current orientation of stream<\/i>. It returns a positive value if stream<\/i> is wide-character oriented, that is, if wide-character I\/O is permitted but char I\/O is disallowed. It returns a negative value if stream<\/i> is byte oriented\u2014that is, if char I\/O is permitted but wide-character I\/O is disallowed. It returns zero if stream<\/i> has no orientation yet; in this case the next I\/O operation might change the orientation (to byte oriented if it is a char I\/O operation, or to wide-character oriented if it is a wide-character I\/O operation).<\/p>\n Once a stream has an orientation, it cannot be changed and persists until the stream is closed.<\/p>\n When mode<\/i> is nonzero, the fwide<\/b>() function first attempts to set stream<\/i>\u2019s orientation (to wide-character oriented if mode<\/i> is greater than 0, or to byte oriented if mode<\/i> is less than 0). It then returns a value denoting the current orientation, as above.<\/p>\n The fwide<\/b>() function returns the stream\u2019s orientation, after possibly changing it. A positive return value means wide-character oriented. A negative return value means byte oriented. A return value of zero means undecided.<\/p>\n POSIX.1-2001, POSIX.1-2008, C99.<\/p>\n Wide-character output to a byte oriented stream can be performed through the fprintf<\/b>(3) function with the %lc<\/b> and %ls<\/b> directives.<\/p>\n Char oriented output to a wide-character oriented stream can be performed through the fwprintf<\/b>(3) function with the %c<\/b> and %s<\/b> directives.<\/p>\n
SYNOPSIS<\/a>
DESCRIPTION<\/a>
RETURN VALUE<\/a>
CONFORMING TO<\/a>
NOTES<\/a>
SEE ALSO<\/a>
COLOPHON<\/a> <\/p>\n
\nNAME <\/a> <\/h2>\n
SYNOPSIS <\/a> <\/h2>\n
_POSIX_C_SOURCE\u00a0>=\u00a0200112L<\/p>\nDESCRIPTION <\/a> <\/h2>\n
RETURN VALUE <\/a> <\/h2>\n
CONFORMING TO <\/a> <\/h2>\n
NOTES <\/a> <\/h2>\n
SEE ALSO <\/a> <\/h2>\n