In the last episode (Feb 08), Loren M. Lang said:
I'm looking for a replacement for the strace program I used to use on
linux; freebsd has a port of strace, but it just hangs everytime I
use it. It looks like the bsd version of strace would be
ktrace/kdump. I was able to get these to print a trace of the
program I ran, but it doesn't do all the nice substatuting that
strace was able to do. Mainly, I just want the first argument of open
to look like a string instead of a 32 bit pointer that I can't read. I'm trying to figure out what files this program is trying to read so
I can edit it's configuration file.
The string in the NAMI line immediately after an open() call is the filename in kdump output.
strace actually does work, but I think it's losing a race when it forks the child process. Try suspending and resuming strace:
([EMAIL PROTECTED]) /home/dan> strace date <hangs here, hit ^Z> ^Z zsh: 62219 suspended strace date [1] + suspended strace date ([EMAIL PROTECTED]) /home/dan> fg [1] + continued strace date execve(0xbfbfdef4, [0xbfbfe3b8], [/* 0 vars */]) = 0 mmap(0, 3920, PROT_READ|PROT_WRITE, MAP_ANON, -1, 0) = 0x28071000 munmap(0x28071000, 3920) = 0 ...
strace hasn't been updated in a while, though, and has problems parsing newer syscalls. Take a look at the truss command in the base system, which does about the same thing as strace. Ktrace has the advantage that it's less intrusive; both strace and truss have to stop the process to print out data, which really slow it down.
Is truss still being fixed to work without procfs or is ktrace a better replacement?
Chris _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
