import sys, os
import contextlib
import subprocess
# find_library(name) returns the pathname of a library, or None.
if os.name == "nt":
def _get_build_version():
"""Return the version of MSVC that was used to build Python.
For Python 2.3 and up, the version number is included in
sys.version. For earlier versions, assume the compiler is MSVC 6.
"""
# This function was copied from Lib/distutils/msvccompiler.py
prefix = "MSC v."
i = sys.version.find(prefix)
if i == -1:
return 6
i = i + len(prefix)
s, rest = sys.version[i:].split(" ", 1)
majorVersion = int(s[:-2]) - 6
minorVersion = int(s[2:3]) / 10.0
# I don't think paths are affected by minor version in version 6
if majorVersion == 6:
minorVersion = 0
if majorVersion >= 6:
return majorVersion + minorVersion
# else we don't know what version of the compiler this is
return None
def find_msvcrt():
"""Return the name of the VC runtime dll"""
version = _get_build_version()
if version is None:
# better be safe than sorry
return None
if version <= 6:
clibname = 'msvcrt'
else:
clibname = 'msvcr%d' % (version * 10)
# If python was built with in debug mode
import importlib.machinery
if '_d.pyd' in importlib.machinery.EXTENSION_SUFFIXES:
clibname += 'd'
return clibname+'.dll'
def find_library(name):
if name in ('c', 'm'):
return find_msvcrt()
# See MSDN for the REAL search order.
for directory in os.environ['PATH'].split(os.pathsep):
fname = os.path.join(directory, name)
if os.path.isfile(fname):
return fname
if fname.lower().endswith(".dll"):
continue
fname = fname + ".dll"
if os.path.isfile(fname):
return fname
return None
if os.name == "ce":
# search path according to MSDN:
# - absolute path specified by filename
# - The .exe launch directory
# - the Windows directory
# - ROM dll files (where are they?)
# - OEM specified search path: HKLM\Loader\SystemPath
def find_library(name):
return name
if os.name == "posix" and sys.platform == "darwin":
from ctypes.macholib.dyld import dyld_find as _dyld_find
def find_library(name):
possible = ['lib%s.dylib' % name,
'%s.dylib' % name,
'%s.framework/%s' % (name, name)]
for name in possible:
try:
return _dyld_find(name)
except ValueError:
continue
return None
elif os.name == "posix":
# Andreas Degert's find functions, using gcc, /sbin/ldconfig, objdump
import re, tempfile
def _findLib_gcc(name):
expr = r'[^\(\)\s]*lib%s\.[^\(\)\s]*' % re.escape(name)
fdout, ccout = tempfile.mkstemp()
os.close(fdout)
cmd = 'if type gcc >/dev/null 2>&1; then CC=gcc; elif type cc >/dev/null 2>&1; then CC=cc;else exit 10; fi;' \
'LANG=C LC_ALL=C $CC -Wl,-t -o ' + ccout + ' 2>&1 -l' + name
try:
f = os.popen(cmd)
try:
trace = f.read()
finally:
rv = f.close()
finally:
try:
os.unlink(ccout)
except FileNotFoundError:
pass
if rv == 10:
raise OSError('gcc or cc command not found')
res = re.search(expr, trace)
if not res:
return None
return res.group(0)
if sys.platform == "sunos5":
# use /usr/ccs/bin/dump on solaris
def _get_soname(f):
if not f:
return None
cmd = "/usr/ccs/bin/dump -Lpv 2>/dev/null " + f
with contextlib.closing(os.popen(cmd)) as f:
data = f.read()
res = re.search(r'\[.*\]\sSONAME\s+([^\s]+)', data)
if not res:
return None
return res.group(1)
else:
def _get_soname(f):
# assuming GNU binutils / ELF
if not f:
return None
cmd = 'if ! type objdump >/dev/null 2>&1; then exit 10; fi;' \
"objdump -p -j .dynamic 2>/dev/null " + f
f = os.popen(cmd)
try:
dump = f.read()
finally:
rv = f.close()
if rv == 10:
raise OSError('objdump command not found')
res = re.search(r'\sSONAME\s+([^\s]+)', dump)
if not res:
return None
return res.group(1)
if sys.platform.startswith(("freebsd", "openbsd", "dragonfly")):
def _num_version(libname):
# "libxyz.so.MAJOR.MINOR" => [ MAJOR, MINOR ]
parts = libname.split(".")
nums = []
try:
while parts:
nums.insert(0, int(parts.pop()))
except ValueError:
pass
return nums or [ sys.maxsize ]
def find_library(name):
ename = re.escape(name)
expr = r':-l%s\.\S+ => \S*/(lib%s\.\S+)' % (ename, ename)
with contextlib.closing(os.popen('/sbin/ldconfig -r 2>/dev/null')) as f:
data = f.read()
res = re.findall(expr, data)
if not res:
return _get_soname(_findLib_gcc(name))
res.sort(key=_num_version)
return res[-1]
elif sys.platform == "sunos5":
def _findLib_crle(name, is64):
if not os.path.exists('/usr/bin/crle'):
return None
if is64:
cmd = 'env LC_ALL=C /usr/bin/crle -64 2>/dev/null'
else:
cmd = 'env LC_ALL=C /usr/bin/crle 2>/dev/null'
with contextlib.closing(os.popen(cmd)) as f:
for line in f.readlines():
line = line.strip()
if line.startswith('Default Library Path (ELF):'):
paths = line.split()[4]
if not paths:
return None
for dir in paths.split(":"):
libfile = os.path.join(dir, "lib%s.so" % name)
if os.path.exists(libfile):
return libfile
return None
def find_library(name, is64 = False):
return _get_soname(_findLib_crle(name, is64) or _findLib_gcc(name))
else:
def _findSoname_ldconfig(name):
import struct
if struct.calcsize('l') == 4:
machine = os.uname().machine + '-32'
else:
machine = os.uname().machine + '-64'
mach_map = {
'x86_64-64': 'libc6,x86-64',
'ppc64-64': 'libc6,64bit',
'sparc64-64': 'libc6,64bit',
's390x-64': 'libc6,64bit',
'ia64-64': 'libc6,IA-64',
}
abi_type = mach_map.get(machine, 'libc6')
# XXX assuming GLIBC's ldconfig (with option -p)
regex = os.fsencode(
'\s+(lib%s\.[^\s]+)\s+\(%s' % (re.escape(name), abi_type))
try:
with subprocess.Popen(['/sbin/ldconfig', '-p'],
stdin=subprocess.DEVNULL,
stderr=subprocess.DEVNULL,
stdout=subprocess.PIPE,
env={'LC_ALL': 'C', 'LANG': 'C'}) as p:
res = re.search(regex, p.stdout.read())
if res:
return os.fsdecode(res.group(1))
except OSError:
pass
def find_library(name):
return _findSoname_ldconfig(name) or _get_soname(_findLib_gcc(name))
################################################################
# test code
def test():
from ctypes import cdll
if os.name == "nt":
print(cdll.msvcrt)
print(cdll.load("msvcrt"))
print(find_library("msvcrt"))
if os.name == "posix":
# find and load_version
print(find_library("m"))
print(find_library("c"))
print(find_library("bz2"))
# getattr
## print cdll.m
## print cdll.bz2
# load
if sys.platform == "darwin":
print(cdll.LoadLibrary("libm.dylib"))
print(cdll.LoadLibrary("libcrypto.dylib"))
print(cdll.LoadLibrary("libSystem.dylib"))
print(cdll.LoadLibrary("System.framework/System"))
else:
print(cdll.LoadLibrary("libm.so"))
print(cdll.LoadLibrary("libcrypt.so"))
print(find_library("crypt"))
if __name__ == "__main__":
test()
