- NAME
-
ftell - Return the current position in a stream.
- SYNOPSIS
#include <stdio.h>
long ftell ( FILE *stream );- DESCRIPTION
-
Returns the current position pointed by the position indicator of the stream. When a file has been opened in binary mode the value obtained corresponds to the number of bytes from the beginning of the file. In files opened in text-mode this is not granted because of carriage-return translations under that mode. The value returned is valid for further calls to fseek.
- PARAMETERS
-
-
stream - Pointer to an open file.
-
- RETURN VALUE
-
On success, the current file pointer position is returned. If an error occurs -1 is returned and the global variable errno is set to a positive value. If the stream is unable to perform seeking operations the return value is undefined.
- SEE ALSO
-
fopen, fseek, fgetpos
- EXAMPLE
link:src/ftell.c[role=include]This program opens a file for reading and calculates its size by simply positioning the file-pointer to the end.
- OUTPUT
$ gcc -Wall ftell.c $ ./a.out test.txt Size of test.txt: 18 bytes.