[Crash-utility] extension module: crash-extscript

[vinayak menon]

Hi Dave,

I have uploaded an extension module named extscript to github
Link: https://github.com/vinayakmenon/crash-extscript

Will it be possible to advertise it on crash utility extension page ?

>From the readme of the project:

Extension module for crash utility, to talk to external scripts

What is extscript utility for ? At times we need to execute a series
of crash commands to arrive at a result. i.e. we execute a command,
get the output, pick an element from it, use it with the next command
and so on. There are cases when this may take several steps. This
utility is to automate these steps. Another use can be to execute a
series of predefined crash commands, parse it to get relevant info and
to generate a bug report.

A brief on the components in this package. (1) A crash utility
extension called 'extscript'. This provides a crash command of the
same name. (2) A script. perlfc.pl is an example script, which can
talk to extscript extension. This script can be used as an example to
write utilities that can talk to extscript extension. (3) A protocol
definition, for communication between 'extscript' and the external
script.

The external script is run as a server by crash utility, when you
invoke the extscript command. The external script serves the crash
utility by additonal commands. The script is not executed as is. We
invoke the script from crash command line. In other words, we talk to
the script from within the crash utility command line.

An example. (1) Copy the extscript.c to extensions folder (2) make
extensions (3) Copy perlfc.pl to crash directory.

crash> extend extensions/extscript.so
crash> extscript -f perl -a perl -a ./perlfc.pl
crash> extscript -b vmallocinfo
crash> extscript -b help

The first command loads the extscript module and adds the command
"extscript" to crash utility. The second command sets up the
environement. This is similar to how we pass arguments to execlp. The
last argument is the script path. This command has to be modified
depending on the kind of script that we are running. The third command
is the bypass command which actually executes the command we have
encoded in the script. In this case "vmallocinfo" is a command that is
defined in perlfc.pl. The extecript bypasses this command to the
script. The output in this case will be vmallocinfo similar
/proc/vmallocinfo, displayed on crash console. Thus in simple words we
are extending crash with additoinal commands encoded in a script. The
"help" command shows all the commands supported by the script and its
usage.

See project page in github for more info.

Thanks,
Vinayak