opensnoop.bt(8) System Manager's Manual opensnoop.bt(8)
NAME
opensnoop.bt - Trace open() syscalls. Uses bpftrace/eBPF.
SYNOPSIS
opensnoop.bt
DESCRIPTION
opensnoop traces the open() syscall, showing which processes are at-
tempting to open which files. This can be useful for determining the
location of config and log files, or for troubleshooting applications
that are failing, specially on startup.
This works by tracing the open() syscall tracepoint.
Since this uses BPF, only the root user can use this tool.
REQUIREMENTS
CONFIG_BPF and bcc.
EXAMPLES
Trace all open() syscalls:
# opensnoop.bt
FIELDS
PID Process ID
TID Thread ID
COMM Process name
FD File descriptor (if success), or -1 (if failed)
ERR Error number (see the system's errno.h)
PATH Open path
OVERHEAD
This traces the open tracepoint and prints output for each event. As
the rate of this is generally expected to be low (< 1000/s), the over-
head is also expected to be negligible. If you have an application that
is calling a high rate of open()s, then test and understand overhead
before use.
SOURCE
This is from bpftrace.
https://github.com/iovisor/bpftrace
Also look in the bpftrace distribution for a companion _examples.txt
file containing example usage, output, and commentary for this tool.
This is a bpftrace version of the bcc tool of the same name. The bcc
tool may provide more options and customizations.
https://github.com/iovisor/bcc
OS
Linux
STABILITY
Unstable - in development.
AUTHOR
Brendan Gregg
SEE ALSO
statsnoop.bt(8), execsnoop.bt(8)
USER COMMANDS 2018-09-08 opensnoop.bt(8)
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