Lib/ctypes/util.py

   1 ######################################################################
   2 #  This file should be kept compatible with Python 2.3, see PEP 291. #
   3 ######################################################################
   4 import sys, os
   5
   6 # find_library(name) returns the pathname of a library, or None.
   7 if os.name == "nt":
   8
   9     def _get_build_version():
  10         """Return the version of MSVC that was used to build Python.
  11
  12         For Python 2.3 and up, the version number is included in
  13         sys.version.  For earlier versions, assume the compiler is MSVC 6.
  14         """
  15         # This function was copied from Lib/distutils/msvccompiler.py
  16         prefix = "MSC v."
  17         i = sys.version.find(prefix)
  18         if i == -1:
  19             return 6
  20         i = i + len(prefix)
  21         s, rest = sys.version[i:].split(" ", 1)
  22         majorVersion = int(s[:-2]) - 6
  23         minorVersion = int(s[2:3]) / 10.0
  24         # I don't think paths are affected by minor version in version 6
  25         if majorVersion == 6:
  26             minorVersion = 0
  27         if majorVersion >= 6:
  28             return majorVersion + minorVersion
  29         # else we don't know what version of the compiler this is
  30         return None
  31
  32     def find_msvcrt():
  33         """Return the name of the VC runtime dll"""
  34         version = _get_build_version()
  35         if version is None:
  36             # better be safe than sorry
  37             return None
  38         if version <= 6:
  39             clibname = 'msvcrt'
  40         else:
  41             clibname = 'msvcr%d' % (version * 10)
  42
  43         # If python was built with in debug mode
  44         import imp
  45         if imp.get_suffixes()[0][0] == '_d.pyd':
  46             clibname += 'd'
  47         return clibname+'.dll'
  48
  49     def find_library(name):
  50         if name in ('c', 'm'):
  51             return find_msvcrt()
  52         # See MSDN for the REAL search order.
  53         for directory in os.environ['PATH'].split(os.pathsep):
  54             fname = os.path.join(directory, name)
  55             if os.path.exists(fname):
  56                 return fname
  57             if fname.lower().endswith(".dll"):
  58                 continue
  59             fname = fname + ".dll"
  60             if os.path.exists(fname):
  61                 return fname
  62         return None
  63
  64 if os.name == "ce":
  65     # search path according to MSDN:
  66     # - absolute path specified by filename
  67     # - The .exe launch directory
  68     # - the Windows directory
  69     # - ROM dll files (where are they?)
  70     # - OEM specified search path: HKLM\Loader\SystemPath
  71     def find_library(name):
  72         return name
  73
  74 if os.name == "posix" and sys.platform == "darwin":
  75     from ctypes.macholib.dyld import dyld_find as _dyld_find
  76     def find_library(name):
  77         possible = ['lib%s.dylib' % name,
  78                     '%s.dylib' % name,
  79                     '%s.framework/%s' % (name, name)]
  80         for name in possible:
  81             try:
  82                 return _dyld_find(name)
  83             except ValueError:
  84                 continue
  85         return None
  86
  87 elif os.name == "posix":
  88     # Andreas Degert's find functions, using gcc, /sbin/ldconfig, objdump
  89     import re, tempfile, errno
  90
  91     def _findLib_gcc(name):
  92         expr = r'[^\(\)\s]*lib%s\.[^\(\)\s]*' % re.escape(name)
  93         fdout, ccout = tempfile.mkstemp()
  94         os.close(fdout)
  95         cmd = 'if type gcc >/dev/null 2>&1; then CC=gcc; else CC=cc; fi;' \
  96               '$CC -Wl,-t -o ' + ccout + ' 2>&1 -l' + name
  97         try:
  98             f = os.popen(cmd)
  99             trace = f.read()
 100             f.close()
 101         finally:
 102             try:
 103                 os.unlink(ccout)
 104             except OSError, e:
 105                 if e.errno != errno.ENOENT:
 106                     raise
 107         res = re.search(expr, trace)
 108         if not res:
 109             return None
 110         return res.group(0)
 111
 112
 113     if sys.platform == "sunos5":
 114         # use /usr/ccs/bin/dump on solaris
 115         def _get_soname(f):
 116             if not f:
 117                 return None
 118             cmd = "/usr/ccs/bin/dump -Lpv 2>/dev/null " + f
 119             res = re.search(r'\[.*\]\sSONAME\s+([^\s]+)', os.popen(cmd).read())
 120             if not res:
 121                 return None
 122             return res.group(1)
 123     else:
 124         def _get_soname(f):
 125             # assuming GNU binutils / ELF
 126             if not f:
 127                 return None
 128             cmd = "objdump -p -j .dynamic 2>/dev/null " + f
 129             res = re.search(r'\sSONAME\s+([^\s]+)', os.popen(cmd).read())
 130             if not res:
 131                 return None
 132             return res.group(1)
 133
 134     if (sys.platform.startswith("freebsd")
 135         or sys.platform.startswith("openbsd")
 136         or sys.platform.startswith("dragonfly")):
 137
 138         def _num_version(libname):
 139             # "libxyz.so.MAJOR.MINOR" => [ MAJOR, MINOR ]
 140             parts = libname.split(".")
 141             nums = []
 142             try:
 143                 while parts:
 144                     nums.insert(0, int(parts.pop()))
 145             except ValueError:
 146                 pass
 147             return nums or [ sys.maxint ]
 148
 149         def find_library(name):
 150             ename = re.escape(name)
 151             expr = r':-l%s\.\S+ => \S*/(lib%s\.\S+)' % (ename, ename)
 152             res = re.findall(expr,
 153                              os.popen('/sbin/ldconfig -r 2>/dev/null').read())
 154             if not res:
 155                 return _get_soname(_findLib_gcc(name))
 156             res.sort(cmp= lambda x,y: cmp(_num_version(x), _num_version(y)))
 157             return res[-1]
 158
 159     else:
 160
 161         def _findLib_ldconfig(name):
 162             # XXX assuming GLIBC's ldconfig (with option -p)
 163             expr = r'/[^\(\)\s]*lib%s\.[^\(\)\s]*' % re.escape(name)
 164             res = re.search(expr,
 165                             os.popen('/sbin/ldconfig -p 2>/dev/null').read())
 166             if not res:
 167                 # Hm, this works only for libs needed by the python executable.
 168                 cmd = 'ldd %s 2>/dev/null' % sys.executable
 169                 res = re.search(expr, os.popen(cmd).read())
 170                 if not res:
 171                     return None
 172             return res.group(0)
 173
 174         def find_library(name):
 175             return _get_soname(_findLib_ldconfig(name) or _findLib_gcc(name))
 176
 177 ################################################################
 178 # test code
 179
 180 def test():
 181     from ctypes import cdll
 182     if os.name == "nt":
 183         print cdll.msvcrt
 184         print cdll.load("msvcrt")
 185         print find_library("msvcrt")
 186
 187     if os.name == "posix":
 188         # find and load_version
 189         print find_library("m")
 190         print find_library("c")
 191         print find_library("bz2")
 192
 193         # getattr
 194 ##        print cdll.m
 195 ##        print cdll.bz2
 196
 197         # load
 198         if sys.platform == "darwin":
 199             print cdll.LoadLibrary("libm.dylib")
 200             print cdll.LoadLibrary("libcrypto.dylib")
 201             print cdll.LoadLibrary("libSystem.dylib")
 202             print cdll.LoadLibrary("System.framework/System")
 203         else:
 204             print cdll.LoadLibrary("libm.so")
 205             print cdll.LoadLibrary("libcrypt.so")
 206             print find_library("crypt")
 207
 208 if __name__ == "__main__":
 209     test()