opensnoop(1m)

NAME
opensnoop - snoop file opens as they occur. Uses DTrace.

SYNOPSIS
opensnoop [-a|-A|-ceghsvxZ] [-f pathname] [-n name] [-p PID]

DESCRIPTION
opensnoop tracks file opens. As a process issues a file open, details such as UID, PID and pathname are printed out. The returned file descriptor is printed, a value of -1 indicates an error. This can be useful for troubleshooting to determine if appliacions are attempting to open files that do not exist. Since this uses DTrace, only users with root privileges can run this command.

OPTIONS

-a  print all data

-A  dump all data, space delimited

-c  print current working directory of process

-e  print errno value

-g  print full command arguments

-s  print start time, us

-v  print start time, string

-x  only print failed opens

-Z  print zonename

-f pathname
    file pathname to snoop

-n name
    process name to snoop

-p PID
    process ID to snoop

EXAMPLES

Default output, print file opens by process as they occur,
    # opensnoop

Print human readable timestamps,
    # opensnoop -v

See error codes,
    # opensnoop -e

Snoop this file only,
    # opensnoop -f /etc/passwd

FIELDS

ZONE
    Zone name

UID User ID

PID Process ID

PPID
    Parent Process ID

FD  File Descriptor (-1 is error)

ERR errno value (see /usr/include/sys/errno.h)

CWD current working directory of process

PATH
    pathname for file open

COMM
    command name for the process

ARGS
    argument listing for the process

TIME
    timestamp for the open event, us

STRTIME
    timestamp for the open event, string

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

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

BUGS
occasionally the pathname for the file open cannot be read and the following error will be seen, dtrace: error on enabled probe ID 6 (...): invalid address this is normal behaviour.

AUTHOR
Brendan Gregg [Sydney, Australia]

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