diff options
Diffstat (limited to 'newlib/libc/stdio/fileno.c')
| -rw-r--r-- | newlib/libc/stdio/fileno.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/newlib/libc/stdio/fileno.c b/newlib/libc/stdio/fileno.c index be8f3d66a..7b505827d 100644 --- a/newlib/libc/stdio/fileno.c +++ b/newlib/libc/stdio/fileno.c @@ -17,23 +17,43 @@ /* FUNCTION -<<fileno>>---return file descriptor associated with stream +<<fileno>>, <<fileno_unlocked>>---return file descriptor associated with stream INDEX fileno +INDEX + fileno_unlocked ANSI_SYNOPSIS #include <stdio.h> int fileno(FILE *<[fp]>); + #define _BSD_SOURCE + #include <stdio.h> + int fileno_unlocked(FILE *<[fp]>); + TRAD_SYNOPSIS #include <stdio.h> int fileno(<[fp]>) FILE *<[fp]>; + #define _BSD_SOURCE + #include <stdio.h> + int fileno_unlocked(<[fp]>) + FILE *<[fp]>; + DESCRIPTION You can use <<fileno>> to return the file descriptor identified by <[fp]>. +<<fileno_unlocked>> is a non-thread-safe version of <<fileno>>. +<<fileno_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 +<<fileno_unlocked>> is equivalent to <<fileno>>. + RETURNS <<fileno>> returns a non-negative integer when successful. If <[fp]> is not an open stream, <<fileno>> returns -1. @@ -42,6 +62,8 @@ PORTABILITY <<fileno>> is not part of ANSI C. POSIX requires <<fileno>>. +<<fileno_unlocked>> is a BSD extension also provided by GNU libc. + Supporting OS subroutines required: none. */ |