Expect.pm (1.04) - Perl Expect interface
use Expect.pm
The Expect module is a successor of Comm.pl and a descendent of Chat.pl. It more closely ressembles the Tcl Expect language than its predecessors. It does not contain any of the networking code found in Comm.pl. I suspect this would be obsolete anyway given the advent of IO::Socket and external tools such as netcat.
Expect.pm is an attempt to have more of a switch() & case: feel to make decision processing more fluid. three separate types of debugging have been implemented to make code production easier.
It is now possible to interconnect multiple file handles (and processes) much like Tcl's expect. An attempt was made to enable all the features of Tcl's expect without forcing Tcl on the victim programmer :-) .
Expect.pm was designed to be generally portable across Unixes.
1. The operating system must include ptys. This excludes non-Unix operating systems as far as I know.
2. The operating system must be POSIX compliant and include the Perl 5 POSIX.pm module. The Fcntl.pm module is also used. My understanding is that there is no POSIX for Microsoft stuff. Bummer.
3. Perl 5.00401+ must be used. This module has been tested with 5.001 and 5.003 under Linux and SunOS 5 and worked fine, but with the new IO::Pty support 5.00401 is required. Expect itself doesn't require this in case at some point IO::Pty should become backwards compatible with earlier versions of Perl.
The old perl 4 Comm.pl was only compatible with SunOS 4 and 5 due to heavy use of ioctl() calls. It is the author's wish that this lack of portability be fixed as much as possible.
Tty settings are a major pain to keep track of. If you find unexpected behavior such as double-echoing or a frozen session doublecheck the documentation for default settings. When in doubt handle them yourself using the exp_stty() and manual_stty() functions. As of .98 you shouldn't have to worry about stty settings getting fouled unless you use interconnect or intentionally change them (like doing -echo to get a password).
If you foul your terminal's tty settings kill any hung processes and enter stty sane at a shell prompt. This should make your terminal manageable again.
This module has not been tested on a great variety of platforms and is relatively young. Interesting and unexpected features will undoubtedly surface.
Austin Schutz <tex@habit.com> Partner/Mad Scientist, The Habit Internet Cafe. Feel free to send any compliments/gripes my way.
And now my shameless commercial plug: Check out Portland's First and Finest 'Net cafe at http://www.habit.com
There are still a few lines of code dating back to the inspirational Comm.pl and Chat.pl modules without which this would not have been possible. Kudos to Eric Arnold <Eric.Arnold@Sun.com> and Randal 'Nuke your NT box with one line of perl code' Schwartz<merlyn@stonehenge.com> for making these available to the perl public.
As of .98 I think all the old code is toast. No way could this have been done without it though. Special thanks to Graham Barr for helping make sense of the IO::Handle stuff as well as providing the highly recommended IO::Tty module.
To install Expect, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Expect
CPAN shell
perl -MCPAN -e shell install Expect
For more information on module installation, please visit the detailed CPAN module installation guide.