[Novalug] How can script know if it's been 'sourced' rather than 'called'?

[Ben Creitz]

On 4/6/07, Michael Stone <mstone at mathom.us> wrote:
> On Fri, Apr 06, 2007 at 02:52:38PM -0400, Richard Rognlie wrote:
> >$ ./test.sh
> >SHELL=/bin/bash
> >0=./test.sh
> >called
> >
> >$ . ./test.sh
> >SHELL=/bin/bash
> >0=/bin/bash
> >sourced
> >
> >$ bash test.sh
> >SHELL=/bin/bash
> >0=test.sh
> >called
>
> user's shell is zsh:
> % . ./test.sh
> SHELL=/usr/bin/zsh
> 0=./test.sh
> called
>
> user's shell is sh:
> $ . ./test.sh
> SHELL=/bin/sh
> 0=sh
> called
>
> user's shell is tcsh:
> > . test.sh
> SHELL=/usr/bin/tcsh
> 0=tcsh
> if: Expression Syntax.

OK, I see what you mean about assumptions.  When we source a file, we
don't get the advantage of the #!/bin/myshell, and that's where the
problem begins, right?

Luckily, I can make all of the required assumptions because this
script is only for me, to be run from  bash, so that I quickly kick
off a session during which I know I'll be logging into a bunch of
servers or running some script that wants to log in to a bunch of
servers.  Having the thing know whether it had been sourced or not was
really just to satisfy my curiosity.

Thanks for the insights, all!