shells and bells

[derek at cerberus.ne.mediaone.net (Derek Martin)]

Today, John Chambers gleaned this insight:

> Though if you are doing anything nontrivial, you  are  almost  always
> better off with perl, tcl or python as your "scripting" language. And
> perl in particular has become standard on just about all unix systems
> since it took over the Web.

I'm largely inclined to agree, but despite that it's worth pointing out
that bourne shell compatible shell scripts will run as-is on virtually any
Unix platform with no extra work, whereas you may need to INSTALL perl to
run your favorite perl script, especially on older platforms. And again,
if you're writing rc scripts, perl isn't generally an option.  The only
shell that's guaranteed to be available at boot time is sh... everything
else is generally located on the /usr partition, which is often mounted
later in the boot process.

This often presented a problem on older platforms if you changed root's
shell to say, csh, and there was a problem with the usr partition.  init
would try to start root's shell, and be unable to, making the system
essentially unbootable.  

I think most of the vendors have worked this out now by simply having init
spawn a statically linked version of sh rather than checking to see what
root's shell was, but HP-UX may be an exception.  I can't remember.


-- 
PGP/GPG Public key at http://cerberus.ne.mediaone.net/~derek/pubkey.txt
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Derek D. Martin      |  Unix/Linux Geek
derekm at mediaone.net  |  derek at cerberus.ne.mediaone.net
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