strace¶

What's strace?¶

• Trace calls to system calls, signals
• Debug programs for which no source is available
• Simple profiling

Profiling¶

strace -wc ./a.out  # wall time

Use strace "in the wild"¶

systemd¶

Prepend the command: ExecStart=/usr/bin/strace /path/to/bin

Replace the binary¹¶

mv /usr/bin/something /usr/bin/something.real

cat <<EOF > /usr/bin/something
#!/usr/bin/env bash

strace "@!" 2>&1 | tee /tmp/something.log.$$
EOF

chmod +x /usr/bin/something