Why can't my script read from STDIN after I gave it EOF
       (^D on Unix, ^Z on MS-DOS)?

       Because some stdio's set error and eof flags that need
       clearing.  The POSIX module defines clearerr() that you
       can use.  That is the technically correct way to do it.
       Here are some less reliable workarounds:

               1   Try keeping around the seekpointer and go
                   there, like this:

                       $where = tell(LOG);
                       seek(LOG, $where, 0);

               2   If that doesn't work, try seeking to a
                   different part of the file and then back.

               3   If that doesn't work, try seeking to a
                   different part of the file, reading something,
                   and then seeking back.

               4   If that doesn't work, give up on your stdio 
                   package and use sysread.
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grep> cd pub
grep> more beer
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