Teams, projects, etc.
We are getting to the time when you really need to be in a team. We
will have a little team match-making during lab today.
strace Tutorial
strace is a relatively simple tool. In its default configuration it
observes some process and prints out information about the system calls
that the process makes as they happen. However, it's still darn useful
for peaking under the covers at what applications are doing.
Trace ls
Trace a simple command, like ls. To save the output, redirect
standard error to a file, like so:
strace ls 2> /tmp/ls.txt
Notice how many system calls there are for even such a humble
application. See how many of the system calls you can interpret
sensibly.
Trace a Running Process
Note: This might not work on the lab machines.
Find a running process that belongs to your user with the top or ps
command. Take a look at its system calls with:
strace -p <process number>
Check Out Some Aggregate Statistics
The -c flag tells strace to gather aggregate statistics. Run a few
commands with this flag and think about how it might be useful for a
CS97 project.
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