Editing DTrace (section)

==Command line examples==
DTrace scripts can be invoked directly from the command line, providing one or more probes and actions as arguments. Some examples:

<syntaxhighlight lang="bash">
# New processes with arguments
dtrace -n 'proc:::exec-success { trace(curpsinfo->pr_psargs); }'

# Files opened by process
dtrace -n 'syscall::open*:entry { printf("%s %s",execname,copyinstr(arg0)); }'

# Syscall count by program
dtrace -n 'syscall:::entry { @num[execname] = count(); }'

# Syscall count by syscall
dtrace -n 'syscall:::entry { @num[probefunc] = count(); }'

# Syscall count by process
dtrace -n 'syscall:::entry { @num[pid,execname] = count(); }'

# Disk size by process
dtrace -n 'io:::start { printf("%d %s %d",pid,execname,args[0]->b_bcount); }'

# Pages paged in by process
dtrace -n 'vminfo:::pgpgin { @pg[execname] = sum(arg0); }'
</syntaxhighlight>

Scripts can also be written which can reach hundreds of lines in length, although typically only tens of lines are needed for advanced troubleshooting and analysis.  Over 200 examples of open source DTrace scripts can be found in the DTraceToolkit,<ref>{{cite web
  | url = http://www.brendangregg.com/dtracetoolkit.html
  | title = DTraceToolkit
  | publisher = [[Brendan Gregg]]
  | access-date=2014-06-08
}}</ref> created by [[Brendan Gregg]] (author of the DTrace book<ref>{{cite book
  | url = http://my.safaribooksonline.com/book/operating-systems-and-server-administration/solaris/9780137061839
  | title = DTrace: Dynamic Tracing in Oracle Solaris, Mac OS X and FreeBSD
  | publisher = [[Safari Books]]
  | isbn = 978-0132091510
  | date = 2011
  | access-date = 2011-01-03
  | archive-date = 2011-04-06
  | archive-url = https://web.archive.org/web/20110406173133/http://my.safaribooksonline.com/book/operating-systems-and-server-administration/solaris/9780137061839
  | url-status = dead
  }}</ref>), which also provides documentation and demonstrations of each.