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     def find_library(name):
   9         # See MSDN for the REAL search order.
  10         for directory in os.environ['PATH'].split(os.pathsep):
  11             fname = os.path.join(directory, name)
  12             if os.path.exists(fname):
  13                 return fname
  14             if fname.lower().endswith(".dll"):
  15                 continue
  16             fname = fname + ".dll"
  17             if os.path.exists(fname):
  18                 return fname
  19         return None
  20
  21 if os.name == "ce":
  22     # search path according to MSDN:
  23     # - absolute path specified by filename
  24     # - The .exe launch directory
  25     # - the Windows directory
  26     # - ROM dll files (where are they?)
  27     # - OEM specified search path: HKLM\Loader\SystemPath
  28     def find_library(name):
  29         return name
  30
  31 if os.name == "posix" and sys.platform == "darwin":
  32     from ctypes.macholib.dyld import dyld_find as _dyld_find
  33     def find_library(name):
  34         possible = ['lib%s.dylib' % name,
  35                     '%s.dylib' % name,
  36                     '%s.framework/%s' % (name, name)]
  37         for name in possible:
  38             try:
  39                 return _dyld_find(name)
  40             except ValueError:
  41                 continue
  42         return None
  43
  44 elif os.name == "posix":
  45     # Andreas Degert's find functions, using gcc, /sbin/ldconfig, objdump
  46     import re, tempfile, errno
  47
  48     def _findLib_gcc(name):
  49         expr = r'[^\(\)\s]*lib%s\.[^\(\)\s]*' % re.escape(name)
  50         fdout, ccout = tempfile.mkstemp()
  51         os.close(fdout)
  52         cmd = 'if type gcc >/dev/null 2>&1; then CC=gcc; else CC=cc; fi;' \
  53               '$CC -Wl,-t -o ' + ccout + ' 2>&1 -l' + name
  54         try:
  55             f = os.popen(cmd)
  56             trace = f.read()
  57             f.close()
  58         finally:
  59             try:
  60                 os.unlink(ccout)
  61             except OSError, e:
  62                 if e.errno != errno.ENOENT:
  63                     raise
  64         res = re.search(expr, trace)
  65         if not res:
  66             return None
  67         return res.group(0)
  68
  69     def _get_soname(f):
  70         # assuming GNU binutils / ELF
  71         if not f:
  72             return None
  73         cmd = "objdump -p -j .dynamic 2>/dev/null " + f
  74         res = re.search(r'\sSONAME\s+([^\s]+)', os.popen(cmd).read())
  75         if not res:
  76             return None
  77         return res.group(1)
  78
  79     if (sys.platform.startswith("freebsd")
  80         or sys.platform.startswith("openbsd")
  81         or sys.platform.startswith("dragonfly")):
  82
  83         def _num_version(libname):
  84             # "libxyz.so.MAJOR.MINOR" => [ MAJOR, MINOR ]
  85             parts = libname.split(".")
  86             nums = []
  87             try:
  88                 while parts:
  89                     nums.insert(0, int(parts.pop()))
  90             except ValueError:
  91                 pass
  92             return nums or [ sys.maxint ]
  93
  94         def find_library(name):
  95             ename = re.escape(name)
  96             expr = r':-l%s\.\S+ => \S*/(lib%s\.\S+)' % (ename, ename)
  97             res = re.findall(expr,
  98                              os.popen('/sbin/ldconfig -r 2>/dev/null').read())
  99             if not res:
 100                 return _get_soname(_findLib_gcc(name))
 101             res.sort(cmp= lambda x,y: cmp(_num_version(x), _num_version(y)))
 102             return res[-1]
 103
 104     else:
 105
 106         def _findLib_ldconfig(name):
 107             # XXX assuming GLIBC's ldconfig (with option -p)
 108             expr = r'/[^\(\)\s]*lib%s\.[^\(\)\s]*' % re.escape(name)
 109             res = re.search(expr,
 110                             os.popen('/sbin/ldconfig -p 2>/dev/null').read())
 111             if not res:
 112                 # Hm, this works only for libs needed by the python executable.
 113                 cmd = 'ldd %s 2>/dev/null' % sys.executable
 114                 res = re.search(expr, os.popen(cmd).read())
 115                 if not res:
 116                     return None
 117             return res.group(0)
 118
 119         def find_library(name):
 120             return _get_soname(_findLib_ldconfig(name) or _findLib_gcc(name))
 121
 122 ################################################################
 123 # test code
 124
 125 def test():
 126     from ctypes import cdll
 127     if os.name == "nt":
 128         print cdll.msvcrt
 129         print cdll.load("msvcrt")
 130         print find_library("msvcrt")
 131
 132     if os.name == "posix":
 133         # find and load_version
 134         print find_library("m")
 135         print find_library("c")
 136         print find_library("bz2")
 137
 138         # getattr
 139 ##        print cdll.m
 140 ##        print cdll.bz2
 141
 142         # load
 143         if sys.platform == "darwin":
 144             print cdll.LoadLibrary("libm.dylib")
 145             print cdll.LoadLibrary("libcrypto.dylib")
 146             print cdll.LoadLibrary("libSystem.dylib")
 147             print cdll.LoadLibrary("System.framework/System")
 148         else:
 149             print cdll.LoadLibrary("libm.so")
 150             print cdll.LoadLibrary("libcrypt.so")
 151             print find_library("crypt")
 152
 153 if __name__ == "__main__":
 154     test()