need shell scripting help

[PeroMed]

Because i also need shell scripting help ill just post my questions here.

How do I make him just write this:
gdb a.out
break main
run
ptype CA

I wrote this and when i run it, it just executed first line.

[PeroMed]

I hope you understand what i mean.

[wowbag1]

I mean this in the nicest possible way, but,I think you need to re-think how you put your question across & state what you are trying to achieve.

[mdnayeem]

Its not at all clear from your post, what you want to do.
Is it that you want to write a shell script which run a gdb debugger for you? break the loop when something criteria is failed, etc.? Could you please a bit more clear.

[PeroMed]

Yes i want my script to run gdb debuger and then set a breakpoint at main
and run the debug. Then the script should write ptype CA so i get my whole CA
class writen on screen or if it is possible to save it in a .txt file
(ptype CA > some.txt doesnt work).


I wrote this shell script:
gdb a.out
break main
run
ptype CA

But it didnt work.
It just ran gdb debuger and nothing else.

I hope you understand what i mean now.

Sorry for my previous post.

[sc0rpi0n]

Create a file with your GDB command inside say "cmd1" then run:

gdb -x cmd1 a.out

Scorp

[PeroMed]

I dont understand what does this do scorp?

Tnx for your reply

[Cabhan]

Alrighty. We need to go back to a few basics.

A Bash script is a script for the Bash shell. When you execute it, Bash will execute each command in sequence. So your script tells Bash: "Run the command 'gdb a.out'. When that finishes, run the command 'break main'. When that finishes, run the command 'run'. When that finishes, run the command 'ptype CA'." Obviously, this is not what you want.

What you want is to run "gdb a.out", and have it automatically run those commands. And by looking at the gdb man page, I see the following:

       -command=file

       -x file
               Execute GDB commands from file file.

So this is where scorp's advice comes in. Let's create a new file called "gdb_commands", and in it, we will put:

break main
run
ptype CA

Now, we can run gdb by saying:

gdb -x gdb_commands a.out

gdb will read this list of commands and process it.

Does that make sense?

[PeroMed]

yes Cabhan that was a very helpful explenation.
Thank you i understand now.