Section 8 · System administration

bcc-bashreadline.8

Package: bcc-tools

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bashreadline

NAME
SYNOPSIS
DESCRIPTION
REQUIREMENTS
OPTIONS
EXAMPLES
FIELDS
OVERHEAD
SOURCE
OS
STABILITY
AUTHOR
SEE ALSO

NAME

bashreadline − Print entered bash commands system wide. Uses Linux eBPF/bcc.

SYNOPSIS

bashreadline [−h] [−s SHARED]

DESCRIPTION

bashreadline traces the return of the readline() function using uprobes, to show the bash commands that were entered interactively, system wide. The entered command may fail: this is just showing what was entered.

This program is also a basic example of eBPF/bcc and uprobes.

This makes use of a Linux 4.4 feature (bpf_perf_event_output()); for kernels older than 4.4, see the version under tools/old, which uses an older mechanism

Since this uses BPF, only the root user can use this tool.

REQUIREMENTS

CONFIG_BPF and bcc.

OPTIONS


	−h		Print usage message.
	−s		Specify the location of libreadline.so shared library when you failed to run the script directly with error: “Exception: could not determine address of symbol ´readline´”. Default value is /lib/libreadline.so.

EXAMPLES

Trace bash commands system wide:

bashreadline

FIELDS


	TIME		Time of the command (HH:MM:SS).
	PID		Process ID of the bash shell.

COMMAND

Entered command.

OVERHEAD

As the rate of interactive bash commands is expected to be very low (<<100/s), the overhead of this program is expected to be negligible.

SOURCE

This is from bcc.

https://github.com/iovisor/bcc

Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.

OS

Linux

STABILITY

Unstable - in development.

AUTHOR

Brendan Gregg