Here are the DTrace scripts that are used as examples in the Solaris Dynamic Tracing Guide. For more information on any one script, follow the link to its corresponding chapter.
Chapter Script Chapter 1: Introduction countdown.d counter.d hello.d rwtime.d trussrw.d Chapter 3: Variables clause.d rtime.d Chapter 7: Structs and Unions kstat.d ksyms.d rwinfo.d Chapter 9: Aggregations clear.d dateprof.d denorm.d lquantize.d normalize.d renormalize.d trunc.d writes.d writesbycmd.d writesbycmdfd.d writetime.d writetimeq.d Chapter 10: Actions and Subroutines time.d Chapter 11: Buffers and Buffering ring.d Chapter 12: Output Formatting printa.d Chapter 13: Speculative Tracing spec.d specopen.d Chapter 15: Scripting interp.d syscall.d tracewrite.d Chapter 17: dtrace Provider begin.d end.d error.d Chapter 18: lockstat Provider whatlock.d Chapter 19: profile Provider prof.d profpri.d restest.d Chapter 20: fbt Provider delay.d putnext.d ssd.d xioctl.d Chapter 22: sdt Provider callout.d interval.d intr.d Chapter 23: sysinfo Provider find.d Chapter 24: vminfo Provider soffice.d Chapter 25: proc Provider lwptime.d progtime.d sig.d whoexec.d Chapter 26: sched Provider firebird.d howlong.d nscd.d pri.d pritime.d qlen.d qtime.d tick.d ticktime.d whatfor.d where.d whererun.d whofor.d whopreempt.d whoqueue.d whosteal.d xterm.d xwork.d Chapter 27: io Provider applicat.d iocpu.d iosnoop.d iothrough.d iotime.d whoio.d whowrite.d Chapter 32: User Process Tracing badopen.d errorpath.d libc.d userfunc.d Chapter 34: Anonymous Tracing iprb.d