osx man page for errinfo

errinfo(1m)							   USER COMMANDS						       errinfo(1m)

NAME
       errinfo - print errno for syscall fails. Uses DTrace.

SYNOPSIS
       errinfo [-a|-A|-hsvZ] [-c command]

DESCRIPTION
       errinfo snoops syscall failures and prints the errno value and description of the error number.

       This program can help determine if applications are silently failing, providing some details on the cause.

       Since this uses DTrace, only users with root privileges can run this command.

OPTIONS
       -c     counts - print an aggregate style report containing a frequency count of errors

       -p PID examine this PID only

       -n name
	      examine processes with ths name only (eg, "ls")

EXAMPLES
       Default output, print errors as they occur,
	      # errinfo

       Print a frequency count report,
	      # errinfo -c

       Snoop errors as they occur for "ssh" processes,
	      # errinfo -n ssh PP

       Snoop errors for PID 81 only,
	      # errinfo -p 81

FIELDS
       EXEC   Program name (truncated)

       SYSCALL
	      System call name

       ERR    Value of errno

       DESC   Description of errno message

DOCUMENTATION
       See the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may include full worked examples with ver-
       bose descriptions explaining the output.

EXIT
       errinfo will run forever until Ctrl-C is hit.

FILES
       /usr/include/sys/errno.h
	      Contains the full descriptions for the error numbers.

AUTHOR
       Brendan Gregg [Sydney, Australia]

SEE ALSO
       dtrace(1M), truss(1)

version 1.10							   May 14, 2005 						       errinfo(1m)