FreeBSD Install Strace – A Process Tracer And Debugging Tool

Q. How do I install Strace utility under FreeBSD operating system so that I can trace and debug my applications and report 3rd party software bugs?

A. Strace is a process tracer, i.e. a debugging tool that prints out a trace of all the system calls made and signals received by a process itself or a process and its descendants.

Strace is similar to the native BSD truss utility, but it's output style is more convenient in most cases.

For strace to work, procfs has to be mounted. FreeBSD does not mount it by default.

WARNING! These examples only work for i386 32 bit FreeBSD computer (strace is not ported to amd64 arch [64 bit]).

Install strace

First update FreeBSD ports collection and install strace from /usr/ports/devel/strace:
# portsnap fetch update
# cd /usr/ports/devel/strace
# make install clean

Mount /proc file system

You need to mount /proc filesystem to use trace command under FreeBSD, enter:
# mount -t procfs proc /proc

How do I use Strace tool?

Please see our previous FAQ / tutorials about strace command:

1. Debugging Tip: Trace the Process and See What It is Doing with strace
2. Truss like command under Linux to monitor and diagnostic the system calls

Featured Articles:

• 20 Linux System Monitoring Tools Every SysAdmin Should Know
• 20 Linux Server Hardening Security Tips
• My 10 UNIX Command Line Mistakes
• Linux: 20 Iptables Examples For New SysAdmins
• 25 PHP Security Best Practices For Sys Admins
• The Novice Guide To Buying A Linux Laptop
• 10 Greatest Open Source Software Of 2009
• Top 5 Email Client For Linux, Mac OS X, and Windows Users
• Top 20 OpenSSH Server Best Security Practices
• Top 10 Open Source Web-Based Project Management Software
• Top 5 Linux Video Editor Software