Perl 5 version 30.0 documentation
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 emphasis on bytes: even if the filehandle has been set to operate on characters (for example using the
:encoding(UTF-8)I/O layer), the seek, tell, and sysseek family of functions use byte offsets, not character offsets, because seeking to a character offset would be very slow in a UTF-8 file.
There is no
systellfunction. Use sysseek($fh, 0, 1) for that.