static void calculate_path(void) { wchar_t argv0_path[MAXPATHLEN+1]; wchar_t *buf; size_t bufsz; wchar_t *pythonhome = Py_GetPythonHome(); wchar_t *envpath = NULL; int skiphome, skipdefault; wchar_t *machinepath = NULL; wchar_t *userpath = NULL; wchar_t zip_path[MAXPATHLEN+1]; if (!Py_IgnoreEnvironmentFlag) { envpath = _wgetenv(L"PYTHONPATH"); } get_progpath(); /* progpath guaranteed \0 terminated in MAXPATH+1 bytes. */ wcscpy_s(argv0_path, MAXPATHLEN+1, progpath); reduce(argv0_path); /* Search for a sys.path file */ { wchar_t spbuffer[MAXPATHLEN+1]; if ((dllpath[0] && !change_ext(spbuffer, dllpath, L"._pth") && exists(spbuffer)) || (progpath[0] && !change_ext(spbuffer, progpath, L"._pth") && exists(spbuffer))) { if (!read_pth_file(spbuffer, prefix, &Py_IsolatedFlag, &Py_NoSiteFlag)) { return; } } } /* Search for an environment configuration file, first in the executable's directory and then in the parent directory. If found, open it for use when searching for prefixes. */ { wchar_t envbuffer[MAXPATHLEN+1]; wchar_t tmpbuffer[MAXPATHLEN+1]; const wchar_t *env_cfg = L"pyvenv.cfg"; FILE * env_file = NULL; wcscpy_s(envbuffer, MAXPATHLEN+1, argv0_path); join(envbuffer, env_cfg); env_file = _Py_wfopen(envbuffer, L"r"); if (env_file == NULL) { errno = 0; reduce(envbuffer); reduce(envbuffer); join(envbuffer, env_cfg); env_file = _Py_wfopen(envbuffer, L"r"); if (env_file == NULL) { errno = 0; } } if (env_file != NULL) { /* Look for a 'home' variable and set argv0_path to it, if found */ if (find_env_config_value(env_file, L"home", tmpbuffer)) { wcscpy_s(argv0_path, MAXPATHLEN+1, tmpbuffer); } fclose(env_file); env_file = NULL; } } /* Calculate zip archive path from DLL or exe path */ change_ext(zip_path, dllpath[0] ? dllpath : progpath, L".zip"); if (pythonhome == NULL || *pythonhome == '\0') { if (zip_path[0] && exists(zip_path)) { wcscpy_s(prefix, MAXPATHLEN+1, zip_path); reduce(prefix); pythonhome = prefix; } else if (search_for_prefix(argv0_path, LANDMARK)) pythonhome = prefix; else pythonhome = NULL; } else wcscpy_s(prefix, MAXPATHLEN+1, pythonhome); if (envpath && *envpath == '\0') envpath = NULL; skiphome = pythonhome==NULL ? 0 : 1; #ifdef Py_ENABLE_SHARED machinepath = getpythonregpath(HKEY_LOCAL_MACHINE, skiphome); userpath = getpythonregpath(HKEY_CURRENT_USER, skiphome); #endif /* We only use the default relative PYTHONPATH if we havent anything better to use! */ skipdefault = envpath!=NULL || pythonhome!=NULL || \ machinepath!=NULL || userpath!=NULL; /* We need to construct a path from the following parts. (1) the PYTHONPATH environment variable, if set; (2) for Win32, the zip archive file path; (3) for Win32, the machinepath and userpath, if set; (4) the PYTHONPATH config macro, with the leading "." of each component replaced with pythonhome, if set; (5) the directory containing the executable (argv0_path). The length calculation calculates #4 first. Extra rules: - If PYTHONHOME is set (in any way) item (3) is ignored. - If registry values are used, (4) and (5) are ignored. */ /* Calculate size of return buffer */ if (pythonhome != NULL) { wchar_t *p; bufsz = 1; for (p = PYTHONPATH; *p; p++) { if (*p == DELIM) bufsz++; /* number of DELIM plus one */ } bufsz *= wcslen(pythonhome); } else bufsz = 0; bufsz += wcslen(PYTHONPATH) + 1; bufsz += wcslen(argv0_path) + 1; if (userpath) bufsz += wcslen(userpath) + 1; if (machinepath) bufsz += wcslen(machinepath) + 1; bufsz += wcslen(zip_path) + 1; if (envpath != NULL) bufsz += wcslen(envpath) + 1; module_search_path = buf = PyMem_RawMalloc(bufsz*sizeof(wchar_t)); if (buf == NULL) { /* We can't exit, so print a warning and limp along */ fprintf(stderr, "Can't malloc dynamic PYTHONPATH.\n"); if (envpath) { fprintf(stderr, "Using environment $PYTHONPATH.\n"); module_search_path = envpath; } else { fprintf(stderr, "Using default static path.\n"); module_search_path = PYTHONPATH; } PyMem_RawFree(machinepath); PyMem_RawFree(userpath); return; } if (envpath) { if (wcscpy_s(buf, bufsz - (buf - module_search_path), envpath)) Py_FatalError("buffer overflow in getpathp.c's calculate_path()"); buf = wcschr(buf, L'\0'); *buf++ = DELIM; } if (zip_path[0]) { if (wcscpy_s(buf, bufsz - (buf - module_search_path), zip_path)) Py_FatalError("buffer overflow in getpathp.c's calculate_path()"); buf = wcschr(buf, L'\0'); *buf++ = DELIM; } if (userpath) { if (wcscpy_s(buf, bufsz - (buf - module_search_path), userpath)) Py_FatalError("buffer overflow in getpathp.c's calculate_path()"); buf = wcschr(buf, L'\0'); *buf++ = DELIM; PyMem_RawFree(userpath); } if (machinepath) { if (wcscpy_s(buf, bufsz - (buf - module_search_path), machinepath)) Py_FatalError("buffer overflow in getpathp.c's calculate_path()"); buf = wcschr(buf, L'\0'); *buf++ = DELIM; PyMem_RawFree(machinepath); } if (pythonhome == NULL) { if (!skipdefault) { if (wcscpy_s(buf, bufsz - (buf - module_search_path), PYTHONPATH)) Py_FatalError("buffer overflow in getpathp.c's calculate_path()"); buf = wcschr(buf, L'\0'); *buf++ = DELIM; } } else { wchar_t *p = PYTHONPATH; wchar_t *q; size_t n; for (;;) { q = wcschr(p, DELIM); if (q == NULL) n = wcslen(p); else n = q-p; if (p[0] == '.' && is_sep(p[1])) { if (wcscpy_s(buf, bufsz - (buf - module_search_path), pythonhome)) Py_FatalError("buffer overflow in getpathp.c's calculate_path()"); buf = wcschr(buf, L'\0'); p++; n--; } wcsncpy(buf, p, n); buf += n; *buf++ = DELIM; if (q == NULL) break; p = q+1; } } if (argv0_path) { wcscpy(buf, argv0_path); buf = wcschr(buf, L'\0'); *buf++ = DELIM; } *(buf - 1) = L'\0'; /* Now to pull one last hack/trick. If sys.prefix is empty, then try and find it somewhere on the paths we calculated. We scan backwards, as our general policy is that Python core directories are at the *end* of sys.path. We assume that our "lib" directory is on the path, and that our 'prefix' directory is the parent of that. */ if (*prefix==L'\0') { wchar_t lookBuf[MAXPATHLEN+1]; wchar_t *look = buf - 1; /* 'buf' is at the end of the buffer */ while (1) { Py_ssize_t nchars; wchar_t *lookEnd = look; /* 'look' will end up one character before the start of the path in question - even if this is one character before the start of the buffer */ while (look >= module_search_path && *look != DELIM) look--; nchars = lookEnd-look; wcsncpy(lookBuf, look+1, nchars); lookBuf[nchars] = L'\0'; /* Up one level to the parent */ reduce(lookBuf); if (search_for_prefix(lookBuf, LANDMARK)) { break; } /* If we are out of paths to search - give up */ if (look < module_search_path) break; look--; } } }
static void calculate_path(void) { extern wchar_t *Py_GetProgramName(void); static wchar_t delimiter[2] = {DELIM, '\0'}; static wchar_t separator[2] = {SEP, '\0'}; char *_rtpypath = Py_GETENV("PYTHONPATH"); /* XXX use wide version on Windows */ wchar_t *rtpypath = NULL; wchar_t *home = Py_GetPythonHome(); char *_path = getenv("PATH"); wchar_t *path_buffer = NULL; wchar_t *path = NULL; wchar_t *prog = Py_GetProgramName(); wchar_t argv0_path[MAXPATHLEN+1]; wchar_t zip_path[MAXPATHLEN+1]; int pfound, efound; /* 1 if found; -1 if found build directory */ wchar_t *buf; size_t bufsz; size_t prefixsz; wchar_t *defpath; #ifdef WITH_NEXT_FRAMEWORK NSModule pythonModule; const char* modPath; #endif #ifdef __APPLE__ #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_4 uint32_t nsexeclength = MAXPATHLEN; #else unsigned long nsexeclength = MAXPATHLEN; #endif char execpath[MAXPATHLEN+1]; #endif wchar_t *_pythonpath, *_prefix, *_exec_prefix; _pythonpath = _Py_char2wchar(PYTHONPATH, NULL); _prefix = _Py_char2wchar(PREFIX, NULL); _exec_prefix = _Py_char2wchar(EXEC_PREFIX, NULL); if (!_pythonpath || !_prefix || !_exec_prefix) { Py_FatalError( "Unable to decode path variables in getpath.c: " "memory error"); } if (_path) { path_buffer = _Py_char2wchar(_path, NULL); path = path_buffer; } /* If there is no slash in the argv0 path, then we have to * assume python is on the user's $PATH, since there's no * other way to find a directory to start the search from. If * $PATH isn't exported, you lose. */ if (wcschr(prog, SEP)) wcsncpy(progpath, prog, MAXPATHLEN); #ifdef __APPLE__ /* On Mac OS X, if a script uses an interpreter of the form * "#!/opt/python2.3/bin/python", the kernel only passes "python" * as argv[0], which falls through to the $PATH search below. * If /opt/python2.3/bin isn't in your path, or is near the end, * this algorithm may incorrectly find /usr/bin/python. To work * around this, we can use _NSGetExecutablePath to get a better * hint of what the intended interpreter was, although this * will fail if a relative path was used. but in that case, * absolutize() should help us out below */ else if(0 == _NSGetExecutablePath(execpath, &nsexeclength) && execpath[0] == SEP) { size_t r = mbstowcs(progpath, execpath, MAXPATHLEN+1); if (r == (size_t)-1 || r > MAXPATHLEN) { /* Could not convert execpath, or it's too long. */ progpath[0] = '\0'; } } #endif /* __APPLE__ */ else if (path) { while (1) { wchar_t *delim = wcschr(path, DELIM); if (delim) { size_t len = delim - path; if (len > MAXPATHLEN) len = MAXPATHLEN; wcsncpy(progpath, path, len); *(progpath + len) = '\0'; } else wcsncpy(progpath, path, MAXPATHLEN); joinpath(progpath, prog); if (isxfile(progpath)) break; if (!delim) { progpath[0] = L'\0'; break; } path = delim + 1; } } else progpath[0] = '\0'; PyMem_RawFree(path_buffer); if (progpath[0] != SEP && progpath[0] != '\0') absolutize(progpath); wcsncpy(argv0_path, progpath, MAXPATHLEN); argv0_path[MAXPATHLEN] = '\0'; #ifdef WITH_NEXT_FRAMEWORK /* On Mac OS X we have a special case if we're running from a framework. ** This is because the python home should be set relative to the library, ** which is in the framework, not relative to the executable, which may ** be outside of the framework. Except when we're in the build directory... */ pythonModule = NSModuleForSymbol(NSLookupAndBindSymbol("_Py_Initialize")); /* Use dylib functions to find out where the framework was loaded from */ modPath = NSLibraryNameForModule(pythonModule); if (modPath != NULL) { /* We're in a framework. */ /* See if we might be in the build directory. The framework in the ** build directory is incomplete, it only has the .dylib and a few ** needed symlinks, it doesn't have the Lib directories and such. ** If we're running with the framework from the build directory we must ** be running the interpreter in the build directory, so we use the ** build-directory-specific logic to find Lib and such. */ wchar_t* wbuf = _Py_char2wchar(modPath, NULL); if (wbuf == NULL) { Py_FatalError("Cannot decode framework location"); } wcsncpy(argv0_path, wbuf, MAXPATHLEN); reduce(argv0_path); joinpath(argv0_path, lib_python); joinpath(argv0_path, LANDMARK); if (!ismodule(argv0_path)) { /* We are in the build directory so use the name of the executable - we know that the absolute path is passed */ wcsncpy(argv0_path, progpath, MAXPATHLEN); } else { /* Use the location of the library as the progpath */ wcsncpy(argv0_path, wbuf, MAXPATHLEN); } PyMem_RawFree(wbuf); } #endif #if HAVE_READLINK { wchar_t tmpbuffer[MAXPATHLEN+1]; int linklen = _Py_wreadlink(progpath, tmpbuffer, MAXPATHLEN); while (linklen != -1) { if (tmpbuffer[0] == SEP) /* tmpbuffer should never be longer than MAXPATHLEN, but extra check does not hurt */ wcsncpy(argv0_path, tmpbuffer, MAXPATHLEN); else { /* Interpret relative to progpath */ reduce(argv0_path); joinpath(argv0_path, tmpbuffer); } linklen = _Py_wreadlink(argv0_path, tmpbuffer, MAXPATHLEN); } } #endif /* HAVE_READLINK */ reduce(argv0_path); /* At this point, argv0_path is guaranteed to be less than MAXPATHLEN bytes long. */ /* Search for an environment configuration file, first in the executable's directory and then in the parent directory. If found, open it for use when searching for prefixes. */ { wchar_t tmpbuffer[MAXPATHLEN+1]; wchar_t *env_cfg = L"pyvenv.cfg"; FILE * env_file = NULL; wcscpy(tmpbuffer, argv0_path); joinpath(tmpbuffer, env_cfg); env_file = _Py_wfopen(tmpbuffer, L"r"); if (env_file == NULL) { errno = 0; reduce(tmpbuffer); reduce(tmpbuffer); joinpath(tmpbuffer, env_cfg); env_file = _Py_wfopen(tmpbuffer, L"r"); if (env_file == NULL) { errno = 0; } } if (env_file != NULL) { /* Look for a 'home' variable and set argv0_path to it, if found */ if (find_env_config_value(env_file, L"home", tmpbuffer)) { wcscpy(argv0_path, tmpbuffer); } fclose(env_file); env_file = NULL; } } if (!(pfound = search_for_prefix(argv0_path, home, _prefix))) { if (!Py_FrozenFlag) fprintf(stderr, "Could not find platform independent libraries <prefix>\n"); wcsncpy(prefix, _prefix, MAXPATHLEN); joinpath(prefix, lib_python); } else reduce(prefix); wcsncpy(zip_path, prefix, MAXPATHLEN); zip_path[MAXPATHLEN] = L'\0'; if (pfound > 0) { /* Use the reduced prefix returned by Py_GetPrefix() */ reduce(zip_path); reduce(zip_path); } else wcsncpy(zip_path, _prefix, MAXPATHLEN); joinpath(zip_path, L"lib/python00.zip"); bufsz = wcslen(zip_path); /* Replace "00" with version */ zip_path[bufsz - 6] = VERSION[0]; zip_path[bufsz - 5] = VERSION[2]; if (!(efound = search_for_exec_prefix(argv0_path, home, _exec_prefix))) { if (!Py_FrozenFlag) fprintf(stderr, "Could not find platform dependent libraries <exec_prefix>\n"); wcsncpy(exec_prefix, _exec_prefix, MAXPATHLEN); joinpath(exec_prefix, L"lib/lib-dynload"); } /* If we found EXEC_PREFIX do *not* reduce it! (Yet.) */ if ((!pfound || !efound) && !Py_FrozenFlag) fprintf(stderr, "Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]\n"); /* Calculate size of return buffer. */ bufsz = 0; if (_rtpypath && _rtpypath[0] != '\0') { size_t rtpypath_len; rtpypath = _Py_char2wchar(_rtpypath, &rtpypath_len); if (rtpypath != NULL) bufsz += rtpypath_len + 1; } defpath = _pythonpath; prefixsz = wcslen(prefix) + 1; while (1) { wchar_t *delim = wcschr(defpath, DELIM); if (defpath[0] != SEP) /* Paths are relative to prefix */ bufsz += prefixsz; if (delim) bufsz += delim - defpath + 1; else { bufsz += wcslen(defpath) + 1; break; } defpath = delim + 1; } bufsz += wcslen(zip_path) + 1; bufsz += wcslen(exec_prefix) + 1; buf = (wchar_t *)PyMem_Malloc(bufsz*sizeof(wchar_t)); if (buf == NULL) { /* We can't exit, so print a warning and limp along */ fprintf(stderr, "Not enough memory for dynamic PYTHONPATH.\n"); fprintf(stderr, "Using default static PYTHONPATH.\n"); module_search_path = L"" PYTHONPATH; } else { /* Run-time value of $PYTHONPATH goes first */ if (rtpypath) { wcscpy(buf, rtpypath); wcscat(buf, delimiter); } else buf[0] = '\0'; /* Next is the default zip path */ wcscat(buf, zip_path); wcscat(buf, delimiter); /* Next goes merge of compile-time $PYTHONPATH with * dynamically located prefix. */ defpath = _pythonpath; while (1) { wchar_t *delim = wcschr(defpath, DELIM); if (defpath[0] != SEP) { wcscat(buf, prefix); wcscat(buf, separator); } if (delim) { size_t len = delim - defpath + 1; size_t end = wcslen(buf) + len; wcsncat(buf, defpath, len); *(buf + end) = '\0'; } else { wcscat(buf, defpath); break; } defpath = delim + 1; } wcscat(buf, delimiter); /* Finally, on goes the directory for dynamic-load modules */ wcscat(buf, exec_prefix); /* And publish the results */ module_search_path = buf; module_search_path_malloced = 1; } /* Reduce prefix and exec_prefix to their essence, * e.g. /usr/local/lib/python1.5 is reduced to /usr/local. * If we're loading relative to the build directory, * return the compiled-in defaults instead. */ if (pfound > 0) { reduce(prefix); reduce(prefix); /* The prefix is the root directory, but reduce() chopped * off the "/". */ if (!prefix[0]) wcscpy(prefix, separator); } else wcsncpy(prefix, _prefix, MAXPATHLEN); if (efound > 0) { reduce(exec_prefix); reduce(exec_prefix); reduce(exec_prefix); if (!exec_prefix[0]) wcscpy(exec_prefix, separator); } else wcsncpy(exec_prefix, _exec_prefix, MAXPATHLEN); PyMem_RawFree(_pythonpath); PyMem_RawFree(_prefix); PyMem_RawFree(_exec_prefix); PyMem_RawFree(rtpypath); }