December 1994
Intermediate to advanced
606 pages
16h 7m
English
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UNIX System Call Tracing
Before I finish with tracing, I will mention one more tracing aid—for UNIX system calls. Tracing UNIX system calls is totally outside Tcl and yet that is exactly the reason why it is so valuable. Systems calls are precisely the points at which Tcl interacts with the outside world.
By tracing system calls, you can see files being opened and accessed. You can see when your process is sleeping or creating new processes. You can see signals being sent or received. This kind of information is very useful because, after all, programs are run for the side-effects that they have on the outside world. By tracing system calls, you get an idea of all the side-effects that your script is causing.
I will not go into a lot of detail here because so much of this is system specific. However, there are three programs that are particularly useful. truss is a very flexible system call tracer that is found on System V derivatives. trace is a similar program that is found on BSD-based systems. strace is a public-domain version of trace that is a lot better than the original. I highly recommend getting familiar with at least one of these tools.
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.