Updated: 2021/Apr/14

FGETWLN(3)                 Library Functions Manual                 FGETWLN(3)

     fgetwln - get a line of wide characters from a stream

     Standard C Library (libc, -lc)

     #include <stdio.h>
     #include <wchar.h>

     wchar_t *
     fgetwln(FILE * restrict stream, size_t * restrict len);

     The fgetwln() function returns a pointer to the next line from the stream
     referenced by stream.  This line is not a standard wide-character string
     as it does not end with a terminating null wide character.  The length of
     the line, including the final newline, is stored in the memory location
     to which len points.  (Note, however, that if the line is the last in a
     file that does not end in a newline, the returned text will not contain a

     Upon successful completion a pointer is returned; this pointer becomes
     invalid after the next I/O operation on stream (whether successful or
     not) or as soon as the stream is closed.  Otherwise, NULL is returned.
     The fgetwln() function does not distinguish between end-of-file and
     error; the routines feof(3) and ferror(3) must be used to determine which
     occurred.  If an error occurs, the global variable errno is set to
     indicate the error.  The end-of-file condition is remembered, even on a
     terminal, and all subsequent attempts to read will return NULL until the
     condition is cleared with clearerr(3).

     The text to which the returned pointer points may be modified, provided
     that no changes are made beyond the returned size.  These changes are
     lost as soon as the pointer becomes invalid.

     [EBADF]            The argument stream is not a stream open for reading.

     The fgetwln() function may also fail and set errno for any of the errors
     specified for the routines mbrtowc(3), realloc(3), or read(2).

     ferror(3), fgetln(3), fgetws(3), fopen(3)

NetBSD 9.99                      July 16, 2004                     NetBSD 9.99