Re: [Crash-utility] How to use scripts in crash?

> -----Original Message----- > From: crash-utility-bounces(a)redhat.com [mailto:crash-utility- > bounces(a)redhat.com] On Behalf Of Lei Wen > Sent: Wednesday, March 07, 2012 10:58 AM > To: Discussion list for crash utility usage, maintenance and development > Subject: [Crash-utility] How to use scripts in crash? > > Hi Dave, > > Do you have some guide doc that describe how to use the scripts in crash? > Like the example, I want to print out current filesystems registered. > I then need do following > 1. using "p" to get "file_systems" symbol value 2. using "list" with command as > "list -o file_system_type.next -s file_system_type.name,fs_flags <the file_systems symbol value>" > > So if the previous file_systems symbol value could be stored, and then I don't > need to copy the "p" result to "list" command by hand, but could let script do > such kind of thing. > > I also notice there is "sial" script support in crash, but that is too complex for > me... I don't know how to start a basic usage with that... Is there any detailed > doc that could help me from a start? > > Thanks, > Lei > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility Sial is a C interpreter with a few twists like the string type and its associated operators.

The ps example is a good one. Using args and callbacks, including printing recursively (parent->siblings) the process tree. Let me know if you have questions. I tried to comment the example as much as I could at the time. And yes, check out the readme files. It also has a built in preprocessor which enables you to write/modify debugging code that easily adapts to the linux version of the core you are looking at. All of the type and symbol information from kernel space is available in sial through the dwarf interface. You can combine these 2 features with the built in 'exists' operators on member and variables to enable yet better portability across various linux flavors. SGI and other engineering outfits have been cut&pasting kernel code into sial scripts for years. The hello worl skeleton for a sial command : == string foo_opt(){ return "lt:h"; } string foo_usage() { return "[-l] [-t counter] [-h]\n"; } string foo_help(){return " This is the help for command foo\n"} int foo() { if(tflag) tval=atoi(targ) if(lflag) { printf("lflag is set, targ=[%s], targ); } printf("Hello world!\n"); } == By load'ing this file into crash you automatically create a callable foo command in crash, complete with help and usage. Sial can be extended with 'sial builtins' and associated APis. If there are native crash functions (like back traces and fast searches) that can be useful as a function in sial, we can do that. -Luc