shell programming challenge

[Conrad J. Sabatier]

On Fri, 26 Nov 2004 13:57:31 +0200, Giorgos Keramidas
<keramida at ceid.upatras.gr> wrote:

> On 2004-11-25 17:30, "Conrad J. Sabatier" <conrads at cox.net> wrote:
> >
> > OK, I think I've found what you're looking for:
> >
> > xterm -e "/usr/local/bin/bash --rcfile bash_commands -i"
> >
> > Substitute your program's startup script for "bash_commands" in the
> > above.  Using the "-i" switch to bash forces interactive mode, so
> > when the script exits, you'll be returned to the shell prompt in the
> > xterm. As it turns out, xterm's "-hold" switch is wholly unnecessary
> > here.
> >
> > Note that the "--rcfile" switch, being a "double-hyphened" option,
> > must precede the later "-i" switch in order to be recognized.
> 
> Cool trick!

Thanks.  :-)

> I was thinking something like adding the following to the local
> .bashrc:
> 
> 	[-- .bashrc --]
> 
> 	if [ ! X"${BASHRC_LOCAL}" = X"" ] && \
> 	   [ -r "${BASHRC_LOCAL}" ]; then
> 		. "${BASHRC_LOCAL}"
> 	fi
> 
> Then running xterm with BASHRC_LOCAL set to the path of the local bash
> script:
> 
> 	BASHRC_LOCAL="/path/foo" xterm -e bash
> 
> --rcfile is better though :-)

Yes, it's much simpler, for sure.  :-)

By the way, there are some better testing constructs that eliminate
the need for using the old sh trick of "X$SOMEVAR" to avoid syntax
errors.  The above expression could be written as:

if [ -n ${BASHRC_LOCAL} -a -r ${BASHRC_LOCAL} ]; then ...

Or using opposite logic:

if [ ! -z ${BASHRC_LOCAL} ...

Unix shells are just so damn cool, aren't they?  :-)

-- 
Conrad J. Sabatier <conrads at cox.net> -- "In Unix veritas"