-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 According to Eric Blake on 1/25/2006 7:41 AM: >>>=== begin testexec.sh === >>>#!/bin/ksh >>> >>>exec 5<&0 /bin/ksh <<EOSH >>>echo "First exec: Done." >>>exec 0<&5 >>>echo "Second exec: Done." >>>exit 0 >>>EOSH >>>==== end testexec.sh ==== > > > First line: This could be rewritten "exec /bin/ksh 5<&0 <<EOSH". Either > way, you are replacing the current shell with an invocation of /bin/ksh, > and with fd 5 set to your current stdin, and then with fd 0 set to a pipe > supplied by the contents of the here-doc.
P.S. If you had written this instead: exec /bin/ksh <<EOSH 5<&0 echo "First exec: Done." exec 0<&5 echo "Second exec: Done." exit 0 EOSH then you would have the same behavior as your second example (first, replace fd 0 with the pipe from the here-doc, then copy fd 0 to fd 5; then in the here-doc contents, when copying 5 back to 0, you are making no changes). With redirections, order is important. - -- Life is short - so eat dessert first! Eric Blake [EMAIL PROTECTED] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFD148N84KuGfSFAYARApteAKDLmfTPjcwfNdu4j31Fg5866/HUsACfXQ7A 80k3Ne1IFXAFepx3UTmQyvI= =+LHf -----END PGP SIGNATURE----- -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
