=over =item seek FILEHANDLE,POSITION,WHENCE X X X Sets FILEHANDLE's position, just like the C call of C. FILEHANDLE may be an expression whose value gives the name of the filehandle. The values for WHENCE are C<0> to set the new position I to POSITION, C<1> to set it to the current position plus POSITION, and C<2> to set it to EOF plus POSITION (typically negative). For WHENCE you may use the constants C, C, and C (start of the file, current position, end of the file) from the Fcntl module. Returns C<1> on success, C<0> otherwise. Note the I: even if the filehandle has been set to operate on characters (for example by using the C<:encoding(utf8)> open layer), tell() will return byte offsets, not character offsets (because implementing that would render seek() and tell() rather slow). If you want to position the file for C or C, don't use C, because buffering makes its effect on the file's read-write position unpredictable and non-portable. Use C instead. Due to the rules and rigors of ANSI C, on some systems you have to do a seek whenever you switch between reading and writing. Amongst other things, this may have the effect of calling stdio's clearerr(3). A WHENCE of C<1> (C) is useful for not moving the file position: seek(TEST,0,1); This is also useful for applications emulating C. Once you hit EOF on your read and then sleep for a while, you (probably) have to stick in a dummy seek() to reset things. The C doesn't change the position, but it I clear the end-of-file condition on the handle, so that the next C<< >> makes Perl try again to read something. (We hope.) If that doesn't work (some I/O implementations are particularly cantankerous), you might need something like this: for (;;) { for ($curpos = tell(FILE); $_ = ; $curpos = tell(FILE)) { # search for some stuff and put it into files } sleep($for_a_while); seek(FILE, $curpos, 0); } =back