tell - get current seekpointer on a filehandle |
tell - get current seekpointer on a filehandle
tell FILEHANDLE
tell
Returns the current position in bytes for FILEHANDLE, or -1 on error. FILEHANDLE may be an expression whose value gives the name of the actual filehandle. If FILEHANDLE is omitted, assumes the file last read.
Note the in bytes: even if the filehandle has been set to
operate on characters (for example by using the :utf8
open
layer), tell()
will return byte offsets, not character offsets
(because that would render seek()
and tell()
rather slow).
The return value of tell()
for the standard streams like the STDIN
depends on the operating system: it may return -1 or something else.
tell()
on pipes, fifos, and sockets usually returns -1.
There is no systell
function. Use sysseek(FH, 0, 1)
for that.
Do not use tell()
(or other buffered I/O operations) on a file handle
that has been manipulated by sysread(), syswrite()
or sysseek().
Those functions ignore the buffering, while tell()
does not.
tell - get current seekpointer on a filehandle |