Re: [Help-bash] dry run

[Eric Blake]

On 11/19/2012 06:16 AM, Robert Durkacz wrote:
> My question is why can't such an option or be provided, 

A little thought would show why this will never be implemented.  What
would such an option output for the following:

if complex_command; then
  foo=command1
else
  foo=command2
fi
$foo args

On the line for $foo args, there is no way to know what $foo expands to
unless you have previously executed (not just scanned) the
complex_command.  Therefore, there is no way to dry run what the final
results will be without running things, but running things is counter to
the goal of a dry run.

That said, you might be interested in the bashdb project, which uses
bash hooks to provide a debugger interface where you can single-step
through a bash script; it's not the same as telling you what the script
would do, but it at least lets you control how much or little of the
script is actually run.

-- 
Eric Blake   address@hidden    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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