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

AUTHOR¶

Brendan Gregg

SEE ALSO¶

opensnoop(8)