4.35 getchar_unlocked—non-thread-safe version of getchar (macro)

Synopsis

     #include <stdio.h>
     int getchar_unlocked();
     
     #include <stdio.h>
     int _getchar_unlocked_r(struct _reent *ptr);
     

Description
getchar_unlocked is a non-thread-safe version of getchar declared in stdio.h. getchar_unlocked may only safely be used within a scope protected by flockfile() (or ftrylockfile()) and funlockfile(). These functions 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 getchar_unlocked is equivalent to getchar.

The _getchar_unlocked_r function is simply the reentrant version of getchar_unlocked which passes an addtional reentrancy structure pointer argument: ptr.

Returns
See getchar.

Portability
POSIX 1003.1 requires getchar_unlocked. getchar_unlocked may be implemented as a macro.

Supporting OS subroutines required: close, fstat, isatty, lseek, read, sbrk, write.