On Fri, 2008-02-29 at 01:33 -0600, Mike Miller wrote:
> #!/bin/bash --
> EXEC_DIR=$(builtin cd -P -- "${0%/*}" && builtin pwd)
> echo "$EXEC_DIR"
[...]
> Regarding the above script, is the "--" needed after "bash"? I don't
> think it is because there is nothing else on that line.
The '--' is there for the outside case that you've executed the script
from a directory that starts with a dash.
If I create a directory '-P' and put my script in it, I could see this:
[mike at 3po][~]$ -P/execdir
/bin/bash: -/: invalid option
Usage: /bin/bash [GNU long option] [option] ...
/bin/bash [GNU long option] [option] script-file ...
GNU long options:
--debug
--debugger
[...]
My command had been expanded to be 'bash -P/execdir'. If you add the
two dashes at the top of the script, the actual command executed will
instead be 'bash -- -P/execdir'.
Of course, having a directory with a dash as the first character is
really unlikely, and having actual executables in that directory is a
few orders of magnitude even less likely. It was basically an exercise
in making the script as bombproof as possible.
--
Mike Hicks <hick0088 at tc.umn.edu>
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