macOS で Linux の strace のようにシステムコールトレースを取得したい場合は、dtruss で同等のことができる。
実行例
% sudo dtruss -deflo sudo -u $(id -u -n) sleep 1 PID/THRD RELATIVE ELAPSD CPU SYSCALL(args) = return 83868/0x3967d6: 1084 30 27 open("/dev/dtracehelper\0", 0x2, 0x7FFF5DA57840) = 3 0 83868/0x3967d6: 1382 298 296 ioctl(0x3, 0x80086804, 0x7FFF5DA577C8) = 0 0 83868/0x3967d6: 1387 5 4 close(0x3) = 0 0 83868/0x3967d6: 1440 1 0 thread_selfid(0x3, 0x80086804, 0x7FFF5DA577C8) = 3762134 0 83868/0x3967d6: 1446 6 5 bsdthread_register(0x7FFFBBB0A080, 0x7FFFBBB0A070, 0x2000) = 1073741919 0 83868/0x3967d6: 1488 2 0 ulock_wake(0x1, 0x7FFF5DA56F2C, 0x0) = -1 Err#2 83868/0x3967d6: 1500 1 0 issetugid(0x1, 0x7FFF5DA56F2C, 0x0) = 0 0 83868/0x3967d6: 1573 3 2 mprotect(0x102205000, 0x88, 0x1) = 0 0
- sudo dtruss sudo -u $(id -u -n)
で dtruss は root でコマンドは実行ユーザーで実行している。 - d: 相対タイムスタンプ（単位:マイクロ秒）
- e: 経過時間（単位:マイクロ秒）
- f: 子プロセスもトレースする
- l: プロセスIDとスレッドIDを毎行表示する
- o: CPU時間を表示 （単位:マイクロ秒）
man
NAME
dtruss - process syscall details. Uses DTrace.
SYNOPSIS
dtruss [-acdeflhoLs] [-t syscall] { -p PID | -n name | command }
DESCRIPTION
dtruss prints details on process system calls. It is like a DTrace version of truss, and has been designed to be less intrusive
than truss.
Of particular interest is the elapsed times and on cpu times, which can identify both system calls that are slow to complete,
and those which are consuming CPU cycles.
Since this uses DTrace, only users with root privileges can run this command.
OPTIONS
-a print all details
-b bufsize
dynamic variable buffer size. Increase this if you notice dynamic variable drop errors. The default is "4m" for 4
megabytes per CPU.
-c print system call counts
-d print relative timestamps, us
-e print elapsed times, us
-f follow children as they are forked
-l force printing of pid/lwpid per line
-L don't print pid/lwpid per line
-n name
examine processes with this name
-o print on-cpu times, us
-s print stack backtraces
-p PID examine this PID
-t syscall
examine this syscall only
