Scripting sh sessions

[Bill Nickless]

In article <4861 at mtgzz.att.com>, avr at mtgzz.att.com (a.v.reed) writes:
> 
> In article <9877 at drutx.ATT.COM>, csr at drutx.ATT.COM (Steve Roush) writes:
> >    For strictly interactive use, I use "cu". ....
> >   I do not know of any UNIX programs outside of AT&T that allow scripting
> > of sessions as can be done under DOS.
> 
> Oh yes you do, unless you've never heard of "tee".
> And here is how you script a local sh session:
> 
> $ tee -ia script.out | sh -is 2>&1 | tee -ia script.out

Only one problem.  Unless you are on a tty line, the standard I/O stuff
such as printf buffer a solid 512 bytes.  (That can be changed by adding
a setbuf() line.)  Consider the following program:

----cut here----
#include <stdio.h>

char s[80];

main()
{
	printf("Enter a string:");
	gets(s);
	printf("You entered:%s\n",s);
}
----cut here----

When you execute it in the scripted session, you don't get the prompt
"Enter a string:" until AFTER you've entered it!

This of course can be fixed if you have the source, but that can't be
assumed for every program.

-- 
William (Bill) Kirk Nickless                                 Andrews University
305 Meier                           Computer and Information Science Department
Berrien Springs, MI 49104                                    UNIX Support Group
(616) 471-6515 or (616) 471-3422                  ...!uunet!cucstud!aucis!bnick