1st1 / ptracer

A library for ptrace-based tracing of Python programs

ptracer -- a library for ptrace-based tracing of Python programs

Ptracer is a library providing on-demand system call tracing in Python programs.

Basic Usage

import traceback
import ptracer

def callback(syscall):
    print('{}({}) -> {}'.format(
        syscall.name,
        ', '.join(repr(arg.value) for arg in syscall.args),
        syscall.result.text))
    print('Traceback: ')
    print(''.join(traceback.format_list(syscall.traceback)))

with ptracer.context(callback):
    open('/dev/null', 'wb')

Filtering

Ptracer allows elaborate syscall filtering via the filter argument:

flt = [
    ptracer.SysCallPattern(
        name='open',
        args=[
            re.compile(b'/tmp/.*'),
            lambda arg: arg.value & os.O_WRONLY
        ],
        result=lambda res: res.value > 0
    )
]

with ptracer.context(callback, filter=flt):
    # traced code
    ...

In the above example, ptracer will invoke the callback only for successful attempts to open files in the "/tmp" directory for writing.