Strace indent and colorize

README.md

Strace indent and colorize

Parses strace's output and indents filesystem access calls, colorizing and indenting equally all access to the same file descriptor.

strace_scotch.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import random
import re
import sys
import traceback
from typing import List


class Color:
    BLACK = "\033[0;30m"
    RED = "\033[0;31m"
    GREEN = "\033[0;32m"
    BROWN = "\033[0;33m"
    BLUE = "\033[0;34m"
    PURPLE = "\033[0;35m"
    CYAN = "\033[0;36m"
    LIGHT_GRAY = "\033[0;37m"
    DARK_GRAY = "\033[1;30m"
    LIGHT_RED = "\033[1;31m"
    LIGHT_GREEN = "\033[1;32m"
    YELLOW = "\033[1;33m"
    LIGHT_BLUE = "\033[1;34m"
    LIGHT_PURPLE = "\033[1;35m"
    LIGHT_CYAN = "\033[1;36m"
    LIGHT_WHITE = "\033[1;37m"
    BOLD = "\033[1m"
    FAINT = "\033[2m"
    ITALIC = "\033[3m"
    UNDERLINE = "\033[4m"
    BLINK = "\033[5m"
    NEGATIVE = "\033[7m"
    CROSSED = "\033[9m"
    RESET = "\033[0m"
    # cancel SGR codes if we don't write to a terminal
    if not __import__("sys").stdout.isatty():
        for _ in dir():
            if isinstance(_, str) and _[0] != "_":
                locals()[_] = ""
    else:
        # set Windows console in VT mode
        if __import__("platform").system() == "Windows":
            kernel32 = __import__("ctypes").windll.kernel32
            kernel32.SetConsoleMode(kernel32.GetStdHandle(-11), 7)
            del kernel32


usable_colors = [
    Color.RED,
    Color.GREEN,
    Color.BROWN,
    Color.BLUE,
    Color.PURPLE,
    Color.CYAN,
    Color.LIGHT_GRAY,
    Color.DARK_GRAY,
    Color.LIGHT_RED,
    Color.LIGHT_GREEN,
    Color.YELLOW,
    Color.LIGHT_BLUE,
    Color.LIGHT_PURPLE,
    Color.LIGHT_CYAN,
    Color.LIGHT_WHITE,
]


# Placeholder for when the identifier is returned by the syscall
# noinspection PyPep8Naming
class POS_RETURN:
    pass


id_field_pos = {
    "openat": POS_RETURN,
    "mmap": 4,  ## Special case handled separately
    "pread64": 0,
    "read": 0,
    "close": 0,
    'fstat': 0,
    "mprotect": 0,
    "munmap": 0,
    "lseek": 0,
    "write": 0,
}

ident_indent = {}
ident_color = {}

indent = 2
max_indent = 0

mmap_fd_addrs = {}


def get_or_add_ident(ident: str) -> (int, str):
    global max_indent
    if ident in ident_indent:
        return ident_indent[ident], ident_color[ident]

    max_indent += indent
    color = random.choice(usable_colors)
    ident_indent[ident] = max_indent
    ident_color[ident] = color
    return max_indent, color


def del_ident(ident: str):
    global max_indent
    if ident in ident_indent:
        if ident_indent[ident] == max_indent:
            max_indent -= indent
        del ident_indent[ident]
    if ident in ident_color:
        del ident_color[ident]


def split_unescaped(string: str) -> List[str]:
    return re.split(r'(?<!\\),', string)


class StraceLine:
    def __init__(self, line: str):
        self.line = line.strip()
        self.ident = None
        self.func = None
        self.args = None
        self.ret = None
        self._parse()

    def _parse(self):
        match = re.search(r"(\w+)\((.*)\)\s*=\s*(.+)", self.line)
        self.func = match.group(1)
        self.args = split_unescaped(match.group(2))
        self.ret = match.group(3)

        if self.func not in id_field_pos:
            return

        pos = id_field_pos[self.func]

        if pos == POS_RETURN:
            self.ident = self.ret
        else:
            try:
                self.ident = self.args[pos]
            except KeyError:
                traceback.print_exc()
                print(f"Error refers to line: '{self.line}'")

        if self.func == 'mmap':
            addr = self.ret if self.args[0] == 'NULL' else self.args[0]

            # Try to match existing fd if fd is -1
            if self.ident == '-1':
                if addr in mmap_fd_addrs:
                    self.ident = mmap_fd_addrs[addr]
            else:
                # Store addresses to match munmap
                mmap_fd_addrs[addr] = self.ident

        if self.func == 'munmap':
            if self.ident in mmap_fd_addrs:
                self.ident = mmap_fd_addrs[self.ident]


def main():
    f = sys.stdin
    try:
        if len(sys.argv) > 1:
            f = open(sys.argv[1])

        for line in f.readlines():
            if not line or not line.strip():
                continue

            if line.startswith("+++"):
                print(line)
                continue

            try:
                line = StraceLine(line)
            except:
                print(f"Error refers to line: '{line}'")
                raise

            if not line.ident:
                print(line.line)
                continue

            # noinspection PyShadowingNames
            indent, color = get_or_add_ident(line.ident)

            # Randomize color after close
            if line.func == "close":
                del_ident(line.ident)

            print(" " * indent + color + line.line + Color.RESET)
    finally:
        f.close()


if __name__ == '__main__':
    main()