long ftell(FILE *stream);
off_t ftello(FILE *stream);
off64_t ftello64(FILE *stream);
The ftell() function
returns the current position of the file pointer in a stream.
The ftello() function is identical to
ftell() except for the return type.
The ftello64() function is identical to the ftello() function except that it is able to return file offsets that are greater than 2 gigabytes.
The ftello64() function is a part of the large
Points to a stream whose current position is desired.
If successful, the ftell() and ftello()
functions return the current file position for the stream,
measured in bytes from the beginning of the file.
On failure, they return -1 and and errno is set to one of
the following values:
The file descriptor underlying stream is not valid.
The current file offset cannot be represented correctly in an object
with the specified return type.
The file descriptor underlying stream
is associated with a pipe or FIFO.
Large File Specification, revision 1.5.
The file positions reported by fgetpos(),
ftello() may be incorrect for
files that are open in text mode in the case that the file is
being read, or the case where the file is being written to and
there is buffered data which has not yet been written to the
underlying file. In the case that the file is being written to,
fflush() can be used prior to calling
fgetpos(), ftell(), or
ftello() to ensure the accuracy of these functions.
Text mode files with no buffering do not have this problem; however,
performance can be significantly degraded with buffering turned off.
PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition
- fopen(), fseek(), lseek(), popen(), rewind(), ungetc(), write()
PTC MKS Toolkit 10.2 Documentation Build 28.