squeezah

Need some help with minix!!! To put it simple,what i want is,when i execute a system call, me or the OS,to also print a random message followed be the system call's name i just used.
Any help would be appreciated.

matsp

You will have to add code in the system call function itself to produce this information. This is implemented in most Unix varieties for the strace command.

--
Mats

__________________
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.

squeezah

i need to print the msg with the name of system call ,whatever system call i use.when i typing ls for example with what order this call execute?
if i want to print just something when a call is executing i can put a printf in exec right?but what about the name of the call?

brewbuck

Capturing a process's system calls is usually done with ptrace(). I have no idea if Minix has it, but I assume it does.

squeezah

strace doesnt work in minix...

brewbuck

strace works by using ptrace(). Do you at least have ptrace() on Minix? If not, you'll have to hack the standard library to hook the syscall entry points, which will be a pain.

squeezah

no other way to 'capture' the system call's name??

brewbuck

No. I keep suggesting ptrace() and you keep ignoring it for some reason.

squeezah

am not ignoring it how can i use it?

brewbuck

Surely Minix has a manual? It would be far more informative than my random guesses. Googling for "minix ptrace" might be useful.

CornedBee

It is, I just did. Not quite as helpful as you'd think, though.

__________________
All the buzzt!
CornedBee

"There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
- Flon's Law

squeezah

i use man ptrace and says
Note: This manual page has no relation to Minix. Someone who
knows
ptrace() has to check, or rewrite, this page. :P

brewbuck

Well, Minix is getting old in the tooth. If there's no good manual out there anymore, then the OP will have to resort to random hacking.

Most UNIX-like operating systems provide equivalent functionality through ptrace(), but the details are all slightly different.

CornedBee

You could also look at the source of ptrace. I think it's the kernel function do_trace, here:
https://gforge.cs.vu.nl/plugins/scms...ix&view=markup

__________________
All the buzzt!
CornedBee

"There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
- Flon's Law

squeezah

can i ask something ?maybe is wrong or stupid:P a call is executing through exec right?which is the function that reads from shell and l8r other fuction/call call exec??