_ftell_nolock, _ftelli64_nolock

  • Article

Gets the current position of a file pointer without locking.

Syntax

long _ftell_nolock(
   FILE *stream
);
__int64 _ftelli64_nolock(
   FILE *stream
);

Parameters

stream
Target the FILE structure.

Return value

Same as ftell and _ftelli64. For more information, see ftell, _ftelli64.

Remarks

These functions are non-locking versions of ftell and _ftelli64, respectively. They're identical to ftell and _ftelli64 except that they aren't protected from interference by other threads. These functions might be faster because they don't incur the overhead of locking out other threads. Use these functions only in thread-safe contexts such as single-threaded applications or where the calling scope already handles thread isolation.

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

Requirements

Function Required header Optional header
ftell_nolock <stdio.h> <errno.h>
_ftelli64_nolock <stdio.h> <errno.h>

For more compatibility information, see Compatibility.

See also

Stream I/O
fgetpos
fseek, _fseeki64
_lseek, _lseeki64
ftell, _ftelli64