GDB Python Plugin to Generate De Bruijn Sequences

cyclic.py

#!/usr/bin/env python

from itertools import islice
from string import ascii_lowercase

def de_bruijn(k, n):
    try:
        _ = int(k)
        alphabet = list(map(str, range(k)))
    except (ValueError, TypeError):
        alphabet = k
        k = len(k)

    a = [0] * k * n
    sequence = []

    def db(t, p):
        if t > n:
            if n % p == 0:
                sequence.extend(a[1:p + 1])
        else:
            a[t] = a[t - p]
            db(t + 1, p)
            for j in range(a[t - p] + 1, k):
                a[t] = j
                db(t + 1, t)
    db(1, 1)
    return ''.join(alphabet[i] for i in sequence)

class Cyclic(gdb.Command):
    """Print cyclic sequences."""

    def __init__ (self):
        super (Cyclic, self).__init__ ("cyclic", gdb.COMMAND_USER)

    def invoke(self, arg, from_tty):
        try:
            print(''.join(islice(de_bruijn(ascii_lowercase, 4), int(arg)+1)))
        except ValueError:
            print(arg, "must be an integer, but is not!")


class FindCyclic(gdb.Command):
    """Find cyclic sequences."""

    def __init__ (self):
        super (FindCyclic, self).__init__ ("find-cyclic", gdb.COMMAND_USER)

    def invoke(self, arg, from_tty):
        print(de_bruijn(ascii_lowercase, 4).find(arg))

Cyclic()
FindCyclic()