OS X lacks linux's strace
, but it has dtrace
which is supposed to be so much better.
However, I miss the ability to do simple tracing on individual commands. For example, on linux I can write strace -f gcc hello.c
to caputre all system calls, which gives me the list of all the filenames needed by the compiler to compile my program (the excellent memoize script is built upon this trick)
I want to port memoize on the mac, so I need some kind of strace
. What I actually need is the list of files gcc
reads and writes into, so what I need is more of a truss
. Sure enough can I say dtruss -f gcc hello.c
and get somewhat the same functionality, but then the compiler is run with root priviledges, which is obviously undesirable (apart from the massive security risk, one issue is that the a.out
file is now owned by root 🙂
I then tried dtruss -f sudo -u myusername gcc hello.c
, but this feels a bit wrong, and does not work anyway (I get no a.out
file at all this time, not sure why)
All that long story tries to motivate my original question: how do I get dtrace
to run my command with normal user privileges, just like strace
does in linux ?
Edit: is seems that I'm not the only one wondering how to do this: question #1204256 is pretty much the same as mine (and has the same suboptimal sudo answer 🙂
Best Answer
The easiest way is to use sudo:
Other solution would be to run the debugger first and monitor for new specific processes. E.g.
Then in another Terminal simply run:
Simple as that.
More tricky arguments you can find in the manual:
man dtruss
Alternatively you can attach dtruss to the running user process e.g. on Mac:
or similar on Linux/Unix by using strace:
Another hacky trick could be to execute the command and right after that attach to the process. Here are some examples:
Note:
first sudo is just for caching the password at the first time of running,
this trick doesn't work for quick command lines like
ls, date
as it takes some time untill debugger will attach to the process,you have to type your command in two places,
you can ignore
&
to run the process to the background, if it's already doing that,after finishing debugging, you'll have to manually kill the background process (e.g.
killall -v tail
)