/* Return the initial module search path. */ #include "Python.h" #include "osdefs.h" #include #include #ifdef __APPLE__ #include #endif /* Search in some common locations for the associated Python libraries. * * Two directories must be found, the platform independent directory * (prefix), containing the common .py and .pyc files, and the platform * dependent directory (exec_prefix), containing the shared library * modules. Note that prefix and exec_prefix can be the same directory, * but for some installations, they are different. * * Py_GetPath() carries out separate searches for prefix and exec_prefix. * Each search tries a number of different locations until a ``landmark'' * file or directory is found. If no prefix or exec_prefix is found, a * warning message is issued and the preprocessor defined PREFIX and * EXEC_PREFIX are used (even though they will not work); python carries on * as best as is possible, but most imports will fail. * * Before any searches are done, the location of the executable is * determined. If argv[0] has one or more slashes in it, it is used * unchanged. Otherwise, it must have been invoked from the shell's path, * so we search $PATH for the named executable and use that. If the * executable was not found on $PATH (or there was no $PATH environment * variable), the original argv[0] string is used. * * Next, the executable location is examined to see if it is a symbolic * link. If so, the link is chased (correctly interpreting a relative * pathname if one is found) and the directory of the link target is used. * * Finally, argv0_path is set to the directory containing the executable * (i.e. the last component is stripped). * * With argv0_path in hand, we perform a number of steps. The same steps * are performed for prefix and for exec_prefix, but with a different * landmark. * * Step 1. Are we running python out of the build directory? This is * checked by looking for a different kind of landmark relative to * argv0_path. For prefix, the landmark's path is derived from the VPATH * preprocessor variable (taking into account that its value is almost, but * not quite, what we need). For exec_prefix, the landmark is * pybuilddir.txt. If the landmark is found, we're done. * * For the remaining steps, the prefix landmark will always be * lib/python$VERSION/os.py and the exec_prefix will always be * lib/python$VERSION/lib-dynload, where $VERSION is Python's version * number as supplied by the Makefile. Note that this means that no more * build directory checking is performed; if the first step did not find * the landmarks, the assumption is that python is running from an * installed setup. * * Step 2. See if the $PYTHONHOME environment variable points to the * installed location of the Python libraries. If $PYTHONHOME is set, then * it points to prefix and exec_prefix. $PYTHONHOME can be a single * directory, which is used for both, or the prefix and exec_prefix * directories separated by a colon. * * Step 3. Try to find prefix and exec_prefix relative to argv0_path, * backtracking up the path until it is exhausted. This is the most common * step to succeed. Note that if prefix and exec_prefix are different, * exec_prefix is more likely to be found; however if exec_prefix is a * subdirectory of prefix, both will be found. * * Step 4. Search the directories pointed to by the preprocessor variables * PREFIX and EXEC_PREFIX. These are supplied by the Makefile but can be * passed in as options to the configure script. * * That's it! * * Well, almost. Once we have determined prefix and exec_prefix, the * preprocessor variable PYTHONPATH is used to construct a path. Each * relative path on PYTHONPATH is prefixed with prefix. Then the directory * containing the shared library modules is appended. The environment * variable $PYTHONPATH is inserted in front of it all. Finally, the * prefix and exec_prefix globals are tweaked so they reflect the values * expected by other code, by stripping the "lib/python$VERSION/..." stuff * off. If either points to the build directory, the globals are reset to * the corresponding preprocessor variables (so sys.prefix will reflect the * installation location, even though sys.path points into the build * directory). This seems to make more sense given that currently the only * known use of sys.prefix and sys.exec_prefix is for the ILU installation * process to find the installed Python tree. * * An embedding application can use Py_SetPath() to override all of * these authomatic path computations. * * NOTE: Windows MSVC builds use PC/getpathp.c instead! */ #ifdef __cplusplus extern "C" { #endif #ifndef VERSION #define VERSION "2.1" #endif #ifndef VPATH #define VPATH "." #endif #ifndef PREFIX # ifdef __VMS # define PREFIX "" # else # define PREFIX "/usr/local" # endif #endif #ifndef EXEC_PREFIX #define EXEC_PREFIX PREFIX #endif #ifndef PYTHONPATH #define PYTHONPATH PREFIX "/lib/python" VERSION ":" \ EXEC_PREFIX "/lib/python" VERSION "/lib-dynload" #endif #ifndef LANDMARK #define LANDMARK L"os.py" #endif static wchar_t prefix[MAXPATHLEN+1]; static wchar_t exec_prefix[MAXPATHLEN+1]; static wchar_t progpath[MAXPATHLEN+1]; static wchar_t *module_search_path = NULL; static wchar_t *lib_python = L"lib/python" VERSION; static void reduce(wchar_t *dir) { size_t i = wcslen(dir); while (i > 0 && dir[i] != SEP) --i; dir[i] = '\0'; } static int isfile(wchar_t *filename) /* Is file, not directory */ { struct stat buf; if (_Py_wstat(filename, &buf) != 0) return 0; if (!S_ISREG(buf.st_mode)) return 0; return 1; } static int ismodule(wchar_t *filename) /* Is module -- check for .pyc/.pyo too */ { if (isfile(filename)) return 1; /* Check for the compiled version of prefix. */ if (wcslen(filename) < MAXPATHLEN) { wcscat(filename, Py_OptimizeFlag ? L"o" : L"c"); if (isfile(filename)) return 1; } return 0; } static int isxfile(wchar_t *filename) /* Is executable file */ { struct stat buf; if (_Py_wstat(filename, &buf) != 0) return 0; if (!S_ISREG(buf.st_mode)) return 0; if ((buf.st_mode & 0111) == 0) return 0; return 1; } static int isdir(wchar_t *filename) /* Is directory */ { struct stat buf; if (_Py_wstat(filename, &buf) != 0) return 0; if (!S_ISDIR(buf.st_mode)) return 0; return 1; } /* Add a path component, by appending stuff to buffer. buffer must have at least MAXPATHLEN + 1 bytes allocated, and contain a NUL-terminated string with no more than MAXPATHLEN characters (not counting the trailing NUL). It's a fatal error if it contains a string longer than that (callers must be careful!). If these requirements are met, it's guaranteed that buffer will still be a NUL-terminated string with no more than MAXPATHLEN characters at exit. If stuff is too long, only as much of stuff as fits will be appended. */ static void joinpath(wchar_t *buffer, wchar_t *stuff) { size_t n, k; if (stuff[0] == SEP) n = 0; else { n = wcslen(buffer); if (n > 0 && buffer[n-1] != SEP && n < MAXPATHLEN) buffer[n++] = SEP; } if (n > MAXPATHLEN) Py_FatalError("buffer overflow in getpath.c's joinpath()"); k = wcslen(stuff); if (n + k > MAXPATHLEN) k = MAXPATHLEN - n; wcsncpy(buffer+n, stuff, k); buffer[n+k] = '\0'; } /* copy_absolute requires that path be allocated at least MAXPATHLEN + 1 bytes and that p be no more than MAXPATHLEN bytes. */ static void copy_absolute(wchar_t *path, wchar_t *p, size_t pathlen) { if (p[0] == SEP) wcscpy(path, p); else { if (!_Py_wgetcwd(path, pathlen)) { /* unable to get the current directory */ wcscpy(path, p); return; } if (p[0] == '.' && p[1] == SEP) p += 2; joinpath(path, p); } } /* absolutize() requires that path be allocated at least MAXPATHLEN+1 bytes. */ static void absolutize(wchar_t *path) { wchar_t buffer[MAXPATHLEN+1]; if (path[0] == SEP) return; copy_absolute(buffer, path, MAXPATHLEN+1); wcscpy(path, buffer); } /* search_for_prefix requires that argv0_path be no more than MAXPATHLEN bytes long. */ static int search_for_prefix(wchar_t *argv0_path, wchar_t *home) { size_t n; wchar_t *vpath; /* If PYTHONHOME is set, we believe it unconditionally */ if (home) { wchar_t *delim; wcsncpy(prefix, home, MAXPATHLEN); delim = wcschr(prefix, DELIM); if (delim) *delim = L'\0'; joinpath(prefix, lib_python); joinpath(prefix, LANDMARK); return 1; } /* Check to see if argv[0] is in the build directory */ wcscpy(prefix, argv0_path); joinpath(prefix, L"Modules/Setup"); if (isfile(prefix)) { /* Check VPATH to see if argv0_path is in the build directory. */ vpath = L"" VPATH; wcscpy(prefix, argv0_path); joinpath(prefix, vpath); joinpath(prefix, L"Lib"); joinpath(prefix, LANDMARK); if (ismodule(prefix)) return -1; } /* Search from argv0_path, until root is found */ copy_absolute(prefix, argv0_path, MAXPATHLEN+1); do { n = wcslen(prefix); joinpath(prefix, lib_python); joinpath(prefix, LANDMARK); if (ismodule(prefix)) return 1; prefix[n] = L'\0'; reduce(prefix); } while (prefix[0]); /* Look at configure's PREFIX */ wcsncpy(prefix, L"" PREFIX, MAXPATHLEN); joinpath(prefix, lib_python); joinpath(prefix, LANDMARK); if (ismodule(prefix)) return 1; /* Fail */ return 0; } /* search_for_exec_prefix requires that argv0_path be no more than MAXPATHLEN bytes long. */ static int search_for_exec_prefix(wchar_t *argv0_path, wchar_t *home) { size_t n; /* If PYTHONHOME is set, we believe it unconditionally */ if (home) { wchar_t *delim; delim = wcschr(home, DELIM); if (delim) wcsncpy(exec_prefix, delim+1, MAXPATHLEN); else wcsncpy(exec_prefix, home, MAXPATHLEN); joinpath(exec_prefix, lib_python); joinpath(exec_prefix, L"lib-dynload"); return 1; } /* Check to see if argv[0] is in the build directory. "pybuilddir.txt" is written by setup.py and contains the relative path to the location of shared library modules. */ wcscpy(exec_prefix, argv0_path); joinpath(exec_prefix, L"pybuilddir.txt"); if (isfile(exec_prefix)) { FILE *f = _Py_wfopen(exec_prefix, L"rb"); if (f == NULL) errno = 0; else { char buf[MAXPATHLEN+1]; PyObject *decoded; wchar_t rel_builddir_path[MAXPATHLEN+1]; size_t n; n = fread(buf, 1, MAXPATHLEN, f); buf[n] = '\0'; fclose(f); decoded = PyUnicode_DecodeUTF8(buf, n, "surrogateescape"); if (decoded != NULL) { n = PyUnicode_AsWideChar((PyUnicodeObject*)decoded, rel_builddir_path, MAXPATHLEN); Py_DECREF(decoded); if (n >= 0) { rel_builddir_path[n] = L'\0'; wcscpy(exec_prefix, argv0_path); joinpath(exec_prefix, rel_builddir_path); return -1; } } } } /* Search from argv0_path, until root is found */ copy_absolute(exec_prefix, argv0_path, MAXPATHLEN+1); do { n = wcslen(exec_prefix); joinpath(exec_prefix, lib_python); joinpath(exec_prefix, L"lib-dynload"); if (isdir(exec_prefix)) return 1; exec_prefix[n] = L'\0'; reduce(exec_prefix); } while (exec_prefix[0]); /* Look at configure's EXEC_PREFIX */ wcsncpy(exec_prefix, L"" EXEC_PREFIX, MAXPATHLEN); joinpath(exec_prefix, lib_python); joinpath(exec_prefix, L"lib-dynload"); if (isdir(exec_prefix)) return 1; /* Fail */ return 0; } 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'}; wchar_t *pythonpath = L"" PYTHONPATH; char *_rtpypath = Py_GETENV("PYTHONPATH"); /* XXX use wide version on Windows */ wchar_t rtpypath[MAXPATHLEN+1]; wchar_t *home = Py_GetPythonHome(); char *_path = getenv("PATH"); wchar_t wpath[MAXPATHLEN+1]; 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 = pythonpath; #ifdef WITH_NEXT_FRAMEWORK NSModule pythonModule; #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 if (_path) { size_t r = mbstowcs(wpath, _path, MAXPATHLEN+1); path = wpath; if (r == (size_t)-1 || r > MAXPATHLEN) { /* Could not convert PATH, or it's too long. */ path = NULL; } } /* 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'; 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 */ buf = (wchar_t *)NSLibraryNameForModule(pythonModule); if (buf != 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. */ wcsncpy(argv0_path, buf, 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, buf, MAXPATHLEN); } } #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. */ if (!(pfound = search_for_prefix(argv0_path, home))) { if (!Py_FrozenFlag) fprintf(stderr, "Could not find platform independent libraries \n"); wcsncpy(prefix, L"" 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, L"" 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))) { if (!Py_FrozenFlag) fprintf(stderr, "Could not find platform dependent libraries \n"); wcsncpy(exec_prefix, L"" 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 [:]\n"); /* Calculate size of return buffer. */ bufsz = 0; if (_rtpypath) { size_t s = mbstowcs(rtpypath, _rtpypath, sizeof(rtpypath)/sizeof(wchar_t)); if (s == (size_t)-1 || s >=sizeof(rtpypath)) /* XXX deal with errors more gracefully */ _rtpypath = NULL; if (_rtpypath) bufsz += wcslen(rtpypath) + 1; } 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; /* This is the only malloc call in this file */ 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; } /* 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, L"" 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, L"" EXEC_PREFIX, MAXPATHLEN); } /* External interface */ void Py_SetPath(const wchar_t *path) { if (module_search_path != NULL) { free(module_search_path); module_search_path = NULL; } if (path != NULL) { extern wchar_t *Py_GetProgramName(void); wchar_t *prog = Py_GetProgramName(); wcsncpy(progpath, prog, MAXPATHLEN); exec_prefix[0] = prefix[0] = L'\0'; module_search_path = malloc((wcslen(path) + 1) * sizeof(wchar_t)); if (module_search_path != NULL) wcscpy(module_search_path, path); } } wchar_t * Py_GetPath(void) { if (!module_search_path) calculate_path(); return module_search_path; } wchar_t * Py_GetPrefix(void) { if (!module_search_path) calculate_path(); return prefix; } wchar_t * Py_GetExecPrefix(void) { if (!module_search_path) calculate_path(); return exec_prefix; } wchar_t * Py_GetProgramFullPath(void) { if (!module_search_path) calculate_path(); return progpath; } #ifdef __cplusplus } #endif