4.14 fgetws, fgetws_unlocked—get wide character string from a file or stream

Synopsis

     #include <wchar.h>
     wchar_t *fgetws(wchar_t *__restrict ws, int n,
         FILE *__restrict fp);
     
     #define _GNU_SOURCE
     #include <wchar.h>
     wchar_t *fgetws_unlocked(wchar_t *__restrict ws, int n,
         FILE *__restrict fp);
     
     #include <wchar.h>
     wchar_t *_fgetws_r(struct _reent *ptr, wchar_t *ws,
         int n, FILE *fp);
     
     #include <wchar.h>
     wchar_t *_fgetws_unlocked_r(struct _reent *ptr, wchar_t *ws,
         int n, FILE *fp);
     

Description
Reads at most n-1 wide characters from fp until a newline is found. The wide characters including to the newline are stored in ws. The buffer is terminated with a 0.

fgetws_unlocked is a non-thread-safe version of fgetws. fgetws_unlocked may only safely be used within a scope protected by flockfile() (or ftrylockfile()) and funlockfile(). This function may safely be used in a multi-threaded program if and only if they are called while the invoking thread owns the (FILE *) object, as is the case after a successful call to the flockfile() or ftrylockfile() functions. If threads are disabled, then fgetws_unlocked is equivalent to fgetws.

The _fgetws_r and _fgetws_unlocked_r functions are simply reentrant version of the above and are passed an additional reentrancy structure pointer: ptr.

fgetws_unlocked is a GNU extension.