CasperSecurity
# (c) Zygmunt Krynicki 2005, 2006, 2007, 2008
# Licensed under GPL, see COPYING for the whole text
from __future__ import (
print_function,
absolute_import,
)
import gettext
import grp
import json
import logging
import os
import os.path
import posix
import sys
import subprocess
from CommandNotFound.db.db import SqliteDatabase
if sys.version >= "3":
_gettext_method = "gettext"
else:
_gettext_method = "ugettext"
_ = getattr(gettext.translation("command-not-found", fallback=True), _gettext_method)
def similar_words(word):
"""
return a set with spelling1 distance alternative spellings
based on http://norvig.com/spell-correct.html
"""
alphabet = 'abcdefghijklmnopqrstuvwxyz-_0123456789'
s = [(word[:i], word[i:]) for i in range(len(word) + 1)]
deletes = [a + b[1:] for a, b in s if b]
transposes = [a + b[1] + b[0] + b[2:] for a, b in s if len(b) > 1]
replaces = [a + c + b[1:] for a, b in s for c in alphabet if b]
inserts = [a + c + b for a, b in s for c in alphabet]
return set(deletes + transposes + replaces + inserts)
def user_can_sudo():
try:
groups = posix.getgroups()
return (grp.getgrnam("sudo")[2] in groups or
grp.getgrnam("admin")[2] in groups)
except KeyError:
return False
# the new style DB - if that exists we skip the legacy DB
dbpath = "/var/lib/command-not-found/commands.db"
class CommandNotFound(object):
programs_dir = "programs.d"
max_len = 256
prefixes = (
"/snap/bin",
"/bin",
"/usr/bin",
"/usr/local/bin",
"/sbin",
"/usr/sbin",
"/usr/local/sbin",
"/usr/games")
snap_cmd = "/usr/bin/snap"
output_fd = sys.stderr
def __init__(self, data_dir="/usr/share/command-not-found"):
self.sources_list = self._getSourcesList()
# a new style DB means we can skip loading the old legacy static DB
if os.path.exists(dbpath) and os.access(dbpath, os.R_OK):
self.db = SqliteDatabase(dbpath)
else:
raise FileNotFoundError("Cannot find database")
self.user_can_sudo = user_can_sudo()
self.euid = posix.geteuid()
def spelling_suggestions(self, word, min_len=3):
""" try to correct the spelling """
possible_alternatives = []
if not (min_len <= len(word) <= self.max_len):
return possible_alternatives
for w in similar_words(word):
packages = self.get_packages(w)
for (package, ver, comp) in packages:
possible_alternatives.append((w, package, comp, ver))
return possible_alternatives
def get_packages(self, command):
return self.db.lookup(command)
def get_snaps(self, command):
exact_result = []
mispell_result = []
if not os.path.exists(self.snap_cmd):
logging.debug("%s not exists" % self.snap_cmd)
return [], []
try:
with open(os.devnull) as devnull:
output = subprocess.check_output(
[self.snap_cmd, "advise-snap", "--format=json",
"--command", command],
stderr=devnull,
universal_newlines=True)
except subprocess.CalledProcessError as e:
logging.debug("calling snap advice-snap returned an error: %s" % e)
return [], []
logging.debug("got %s from snap advise-snap" % output)
try:
snaps = json.loads(output)
except json.JSONDecodeError as e:
logging.debug("cannot decoding json: %s" % e)
return [], []
for snap in snaps:
if snap["Command"] == command:
exact_result.append((snap["Snap"], snap["Command"], snap.get("Version")))
else:
mispell_result.append((snap["Command"], snap["Snap"], snap.get("Version")))
return exact_result, mispell_result
def getBlacklist(self):
try:
with open(os.sep.join((os.getenv("HOME", "/root"), ".command-not-found.blacklist"))) as blacklist:
return [line.strip() for line in blacklist if line.strip() != ""]
except IOError:
return []
def _getSourcesList(self):
try:
import apt_pkg
from aptsources.sourceslist import SourcesList
apt_pkg.init()
except (SystemError, ImportError):
return []
sources_list = set([])
# The matcher parses info files from
# /usr/share/python-apt/templates/
# But we don't use the calculated data, skip it
for source in SourcesList(withMatcher=False):
if not source.disabled and not source.invalid:
for component in source.comps:
sources_list.add(component)
return sources_list
def install_prompt(self, package_name):
if not "COMMAND_NOT_FOUND_INSTALL_PROMPT" in os.environ:
return
if package_name:
prompt = _("Do you want to install it? (N/y)")
if sys.version >= '3':
answer = input(prompt)
raw_input = lambda x: x # pyflakes
else:
answer = raw_input(prompt)
if sys.stdin.encoding and isinstance(answer, str):
# Decode the answer so that we get an unicode value
answer = answer.decode(sys.stdin.encoding)
if answer.lower() == _("y"):
if self.euid == 0:
command_prefix = ""
else:
command_prefix = "sudo "
install_command = "%sapt install %s" % (command_prefix, package_name)
print("%s" % install_command, file=sys.stdout)
subprocess.call(install_command.split(), shell=False)
def print_spelling_suggestions(self, word, mispell_packages, mispell_snaps, max_alt=15):
""" print spelling suggestions for packages and snaps """
if len(mispell_packages)+len(mispell_snaps) > max_alt:
print(_("Command '%s' not found, but there are %s similar ones.") % (word, len(mispell_packages)), file=self.output_fd)
self.output_fd.flush()
return
elif len(mispell_packages)+len(mispell_snaps) > 0:
print(_("Command '%s' not found, did you mean:") % word, file=self.output_fd)
for (command, snap, ver) in mispell_snaps:
if ver:
ver = " (%s)" % ver
else:
ver = ""
print(_(" command '%s' from snap %s%s") % (command, snap, ver), file=self.output_fd)
for (command, package, comp, ver) in mispell_packages:
if ver:
ver = " (%s)" % ver
else:
ver = ""
print(_(" command '%s' from deb %s%s") % (command, package, ver), file=self.output_fd)
if len(mispell_snaps) > 0:
print(_("See 'snap info <snapname>' for additional versions."), file=self.output_fd)
elif len(mispell_packages) > 0:
if self.user_can_sudo:
print(_("Try: %s <deb name>") % "sudo apt install", file=self.output_fd)
else:
print(_("Try: %s <deb name>") % "apt install", file=self.output_fd)
self.output_fd.flush()
def _print_exact_header(self, command):
print(_("Command '%(command)s' not found, but can be installed with:") % {
'command': command}, file=self.output_fd)
def advice_single_snap_package(self, command, packages, snaps):
self._print_exact_header(command)
snap = snaps[0]
if self.euid == 0:
print("snap install %s" % snap[0], file=self.output_fd)
elif self.user_can_sudo:
print("sudo snap install %s" % snap[0], file=self.output_fd)
else:
print("snap install %s" % snap[0], file=self.output_fd)
print(_("Please ask your administrator."))
self.output_fd.flush()
def advice_single_deb_package(self, command, packages, snaps):
self._print_exact_header(command)
if self.euid == 0:
print("apt install %s" % packages[0][0], file=self.output_fd)
self.install_prompt(packages[0][0])
elif self.user_can_sudo:
print("sudo apt install %s" % packages[0][0], file=self.output_fd)
self.install_prompt(packages[0][0])
else:
print("apt install %s" % packages[0][0], file=self.output_fd)
print(_("Please ask your administrator."))
if not packages[0][2] in self.sources_list:
print(_("You will have to enable the component called '%s'") % packages[0][2], file=self.output_fd)
self.output_fd.flush()
def sudo(self):
if self.euid != 0 and self.user_can_sudo:
return "sudo "
return ""
def advice_multi_deb_package(self, command, packages, snaps):
self._print_exact_header(command)
pad = max([len(s[0]) for s in snaps+packages])
for i, package in enumerate(packages):
ver = ""
if package[1]:
if i == 0 and len(package) > 1:
ver = " # version %s, or" % (package[1])
else:
ver = " # version %s" % (package[1])
if package[2] in self.sources_list:
print("%sapt install %-*s%s" % (self.sudo(), pad, package[0], ver), file=self.output_fd)
else:
print("%sapt install %-*s%s" % (self.sudo(), pad, package[0], ver) + " (" + _("You will have to enable component called '%s'") % package[2] + ")", file=self.output_fd)
if self.euid != 0 and not self.user_can_sudo:
print(_("Ask your administrator to install one of them."), file=self.output_fd)
self.output_fd.flush()
def advice_multi_snap_packages(self, command, packages, snaps):
self._print_exact_header(command)
pad = max([len(s[0]) for s in snaps+packages])
for i, snap in enumerate(snaps):
ver = ""
if snap[2]:
if i == 0 and len(snaps) > 0:
ver = " # version %s, or" % snap[2]
else:
ver = " # version %s" % snap[2]
print("%ssnap install %-*s%s" % (self.sudo(), pad, snap[0], ver), file=self.output_fd)
print(_("See 'snap info <snapname>' for additional versions."), file=self.output_fd)
self.output_fd.flush()
def advice_multi_mixed_packages(self, command, packages, snaps):
self._print_exact_header(command)
pad = max([len(s[0]) for s in snaps+packages])
for i, snap in enumerate(snaps):
ver=""
if snap[2]:
if i == 0:
ver = " # version %s, or" % snap[2]
else:
ver = " # version %s" % snap[2]
print("%ssnap install %-*s%s" % (self.sudo(), pad, snap[0], ver), file=self.output_fd)
for package in packages:
ver=""
if package[1]:
ver = " # version %s" % package[1]
print("%sapt install %-*s%s" % (self.sudo(), pad, package[0], ver), file=self.output_fd)
if len(snaps) == 1:
print(_("See 'snap info %s' for additional versions.") % snaps[0][0], file=self.output_fd)
else:
print(_("See 'snap info <snapname>' for additional versions."), file=self.output_fd)
self.output_fd.flush()
def advise(self, command, ignore_installed=False):
" give advice where to find the given command to stderr "
def _in_prefix(prefix, command):
" helper that returns if a command is found in the given prefix "
return (os.path.exists(os.path.join(prefix, command))
and not os.path.isdir(os.path.join(prefix, command)))
if len(command) > self.max_len:
return False
if command.startswith("/"):
if os.path.exists(command):
prefixes = [os.path.dirname(command)]
else:
prefixes = []
else:
prefixes = [prefix for prefix in self.prefixes if _in_prefix(prefix, command)]
# check if we have it in a common prefix that may not be in the PATH
if prefixes and not ignore_installed:
if len(prefixes) == 1:
print(_("Command '%(command)s' is available in '%(place)s'") % {"command": command, "place": os.path.join(prefixes[0], command)}, file=self.output_fd)
else:
print(_("Command '%(command)s' is available in the following places") % {"command": command}, file=self.output_fd)
for prefix in prefixes:
print(" * %s" % os.path.join(prefix, command), file=self.output_fd)
missing = list(set(prefixes) - set(os.getenv("PATH", "").split(":")))
if len(missing) > 0:
print(_("The command could not be located because '%s' is not included in the PATH environment variable.") % ":".join(missing), file=self.output_fd)
if "sbin" in ":".join(missing):
print(_("This is most likely caused by the lack of administrative privileges associated with your user account."), file=self.output_fd)
return False
# do not give advice if we are in a situation where apt
# or aptitude are not available (LP: #394843)
if not (os.path.exists("/usr/bin/apt") or
os.path.exists("/usr/bin/aptitude")):
return False
if command in self.getBlacklist():
return False
# python is special, on 20.04 and newer we should encourage
# people to use python3 only, and command-not-found depends on
# python3, so must be available
if command == "python":
print(_("Command '%s' not found, did you mean:") % command, file=self.output_fd)
print(_(" command '%s' from deb %s%s") % ("python3", "python3", ""), file=self.output_fd)
print(_(" command '%s' from deb %s%s") % ("python", "python-is-python3", ""), file=self.output_fd)
return True
packages = self.get_packages(command)
snaps, mispell_snaps = self.get_snaps(command)
logging.debug("got debs: %s snaps: %s" % (packages, snaps))
if len(packages) == 0 and len(snaps) == 0:
mispell_packages = self.spelling_suggestions(command)
if len(mispell_packages) > 0 or len(mispell_snaps) > 0:
self.print_spelling_suggestions(command, mispell_packages, mispell_snaps)
elif len(packages) == 0 and len(snaps) == 1:
self.advice_single_snap_package(command, packages, snaps)
elif len(snaps) > 0 and len(packages) == 0:
self.advice_multi_snap_packages(command, packages, snaps)
elif len(packages) == 1 and len(snaps) == 0:
self.advice_single_deb_package(command, packages, snaps)
elif len(packages) > 1 and len(snaps) == 0:
self.advice_multi_deb_package(command, packages, snaps)
elif len(packages) > 0 and len(snaps) > 0:
self.advice_multi_mixed_packages(command, packages, snaps)
return (len(packages) > 0 or len(snaps) > 0 or
len(mispell_snaps) > 0 or len(mispell_packages) > 0)