mirror of
https://github.com/python/cpython.git
synced 2024-12-06 00:05:32 +08:00
302be44e96
symlink to a symlink can work. (Jack)
613 lines
16 KiB
C
613 lines
16 KiB
C
/***********************************************************
|
|
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
|
|
The Netherlands.
|
|
|
|
All Rights Reserved
|
|
|
|
Permission to use, copy, modify, and distribute this software and its
|
|
documentation for any purpose and without fee is hereby granted,
|
|
provided that the above copyright notice appear in all copies and that
|
|
both that copyright notice and this permission notice appear in
|
|
supporting documentation, and that the names of Stichting Mathematisch
|
|
Centrum or CWI or Corporation for National Research Initiatives or
|
|
CNRI not be used in advertising or publicity pertaining to
|
|
distribution of the software without specific, written prior
|
|
permission.
|
|
|
|
While CWI is the initial source for this software, a modified version
|
|
is made available by the Corporation for National Research Initiatives
|
|
(CNRI) at the Internet address ftp://ftp.python.org.
|
|
|
|
STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
|
|
REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
|
|
MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
|
|
CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
|
|
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
|
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
|
|
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
|
|
PERFORMANCE OF THIS SOFTWARE.
|
|
|
|
******************************************************************/
|
|
|
|
/* Return the initial module search path. */
|
|
|
|
#include "Python.h"
|
|
#include "osdefs.h"
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <string.h>
|
|
|
|
#if HAVE_UNISTD_H
|
|
#include <unistd.h>
|
|
#endif /* HAVE_UNISTD_H */
|
|
|
|
/* 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 slashs 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 $PATH environment
|
|
* variable), the original argv[0] string is used.
|
|
*
|
|
* Next, the executable location is examined to see if it is a symbolic
|
|
* link. If so, the link is chased (correctly interpreting a relative
|
|
* pathname if one is found) and the directory of the link target is used.
|
|
*
|
|
* Finally, argv0_path is set to the directory containing the executable
|
|
* (i.e. the last component is stripped).
|
|
*
|
|
* With argv0_path in hand, we perform a number of steps. The same steps
|
|
* are performed for prefix and for exec_prefix, but with a different
|
|
* landmark.
|
|
*
|
|
* Step 1. Are we running python out of the build directory? This is
|
|
* checked by looking for a different kind of landmark relative to
|
|
* argv0_path. For prefix, the landmark's path is derived from the VPATH
|
|
* preprocessor variable (taking into account that its value is almost, but
|
|
* not quite, what we need). For exec_prefix, the landmark is
|
|
* Modules/Setup. If the landmark is found, we're done.
|
|
*
|
|
* For the remaining steps, the prefix landmark will always be
|
|
* lib/python$VERSION/string.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
|
|
* preprocesor 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.
|
|
*/
|
|
|
|
#ifndef VERSION
|
|
#define VERSION "1.5"
|
|
#endif
|
|
|
|
#ifndef VPATH
|
|
#define VPATH "."
|
|
#endif
|
|
|
|
#ifndef PREFIX
|
|
#define PREFIX "/usr/local"
|
|
#endif
|
|
|
|
#ifndef EXEC_PREFIX
|
|
#define EXEC_PREFIX PREFIX
|
|
#endif
|
|
|
|
#ifndef PYTHONPATH
|
|
/* I know this isn't K&R C, but the Makefile specifies it anyway */
|
|
#define PYTHONPATH PREFIX "/lib/python" VERSION ":" \
|
|
EXEC_PREFIX "/lib/python" VERSION "/lib-dynload"
|
|
#endif
|
|
|
|
#ifndef LANDMARK
|
|
#define LANDMARK "string.py"
|
|
#endif
|
|
|
|
static char prefix[MAXPATHLEN+1];
|
|
static char exec_prefix[MAXPATHLEN+1];
|
|
static char progpath[MAXPATHLEN+1];
|
|
static char *module_search_path = NULL;
|
|
static char lib_python[20]; /* Dynamically set to "lib/python" VERSION */
|
|
|
|
static void
|
|
reduce(dir)
|
|
char *dir;
|
|
{
|
|
int i = strlen(dir);
|
|
while (i > 0 && dir[i] != SEP)
|
|
--i;
|
|
dir[i] = '\0';
|
|
}
|
|
|
|
|
|
#ifndef S_ISREG
|
|
#define S_ISREG(x) (((x) & S_IFMT) == S_IFREG)
|
|
#endif
|
|
|
|
#ifndef S_ISDIR
|
|
#define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR)
|
|
#endif
|
|
|
|
static int
|
|
isfile(filename) /* Is file, not directory */
|
|
char *filename;
|
|
{
|
|
struct stat buf;
|
|
if (stat(filename, &buf) != 0)
|
|
return 0;
|
|
if (!S_ISREG(buf.st_mode))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
|
|
static int
|
|
ismodule(filename) /* Is module -- check for .pyc/.pyo too */
|
|
char *filename;
|
|
{
|
|
if (isfile(filename))
|
|
return 1;
|
|
|
|
/* Check for the compiled version of prefix. */
|
|
if (strlen(filename) < MAXPATHLEN) {
|
|
strcat(filename, Py_OptimizeFlag ? "o" : "c");
|
|
if (isfile(filename))
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int
|
|
isxfile(filename) /* Is executable file */
|
|
char *filename;
|
|
{
|
|
struct stat buf;
|
|
if (stat(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(filename) /* Is directory */
|
|
char *filename;
|
|
{
|
|
struct stat buf;
|
|
if (stat(filename, &buf) != 0)
|
|
return 0;
|
|
if (!S_ISDIR(buf.st_mode))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
|
|
static void
|
|
joinpath(buffer, stuff)
|
|
char *buffer;
|
|
char *stuff;
|
|
{
|
|
int n, k;
|
|
if (stuff[0] == SEP)
|
|
n = 0;
|
|
else {
|
|
n = strlen(buffer);
|
|
if (n > 0 && buffer[n-1] != SEP && n < MAXPATHLEN)
|
|
buffer[n++] = SEP;
|
|
}
|
|
k = strlen(stuff);
|
|
if (n + k > MAXPATHLEN)
|
|
k = MAXPATHLEN - n;
|
|
strncpy(buffer+n, stuff, k);
|
|
buffer[n+k] = '\0';
|
|
}
|
|
|
|
|
|
static int
|
|
search_for_prefix(argv0_path, home)
|
|
char *argv0_path;
|
|
char *home;
|
|
{
|
|
int n;
|
|
char *vpath;
|
|
|
|
/* Check to see if argv[0] is in the build directory */
|
|
strcpy(prefix, argv0_path);
|
|
joinpath(prefix, "Modules/Setup");
|
|
if (isfile(prefix)) {
|
|
/* Check VPATH to see if argv0_path is in the build directory.
|
|
* Complication: the VPATH passed in is relative to the
|
|
* Modules build directory and points to the Modules source
|
|
* directory; we need it relative to the build tree and
|
|
* pointing to the source tree. Solution: chop off a leading
|
|
* ".." (but only if it's there -- it could be an absolute
|
|
* path) and chop off the final component (assuming it's
|
|
* "Modules").
|
|
*/
|
|
vpath = VPATH;
|
|
if (vpath[0] == '.' && vpath[1] == '.' && vpath[2] == '/')
|
|
vpath += 3;
|
|
strcpy(prefix, argv0_path);
|
|
joinpath(prefix, vpath);
|
|
reduce(prefix);
|
|
joinpath(prefix, "Lib");
|
|
joinpath(prefix, LANDMARK);
|
|
if (ismodule(prefix))
|
|
return -1;
|
|
}
|
|
|
|
if (home) {
|
|
/* Check $PYTHONHOME */
|
|
char *delim;
|
|
strcpy(prefix, home);
|
|
delim = strchr(prefix, DELIM);
|
|
if (delim)
|
|
*delim = '\0';
|
|
joinpath(prefix, lib_python);
|
|
joinpath(prefix, LANDMARK);
|
|
if (ismodule(prefix))
|
|
return 1;
|
|
}
|
|
|
|
/* Search from argv0_path, until root is found */
|
|
strcpy(prefix, argv0_path);
|
|
do {
|
|
n = strlen(prefix);
|
|
joinpath(prefix, lib_python);
|
|
joinpath(prefix, LANDMARK);
|
|
if (ismodule(prefix))
|
|
return 1;
|
|
prefix[n] = '\0';
|
|
reduce(prefix);
|
|
} while (prefix[0]);
|
|
|
|
/* Look at configure's PREFIX */
|
|
strcpy(prefix, PREFIX);
|
|
joinpath(prefix, lib_python);
|
|
joinpath(prefix, LANDMARK);
|
|
if (ismodule(prefix))
|
|
return 1;
|
|
|
|
/* Fail */
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int
|
|
search_for_exec_prefix(argv0_path, home)
|
|
char *argv0_path;
|
|
char *home;
|
|
{
|
|
int n;
|
|
|
|
/* Check to see if argv[0] is in the build directory */
|
|
strcpy(exec_prefix, argv0_path);
|
|
joinpath(exec_prefix, "Modules/Setup");
|
|
if (isfile(exec_prefix)) {
|
|
reduce(exec_prefix);
|
|
return -1;
|
|
}
|
|
|
|
if (home) {
|
|
/* Check $PYTHONHOME */
|
|
char *delim;
|
|
delim = strchr(home, DELIM);
|
|
if (delim)
|
|
strcpy(exec_prefix, delim+1);
|
|
else
|
|
strcpy(exec_prefix, home);
|
|
joinpath(exec_prefix, lib_python);
|
|
joinpath(exec_prefix, "lib-dynload");
|
|
if (isdir(exec_prefix))
|
|
return 1;
|
|
}
|
|
|
|
/* Search from argv0_path, until root is found */
|
|
strcpy(exec_prefix, argv0_path);
|
|
do {
|
|
n = strlen(exec_prefix);
|
|
joinpath(exec_prefix, lib_python);
|
|
joinpath(exec_prefix, "lib-dynload");
|
|
if (isdir(exec_prefix))
|
|
return 1;
|
|
exec_prefix[n] = '\0';
|
|
reduce(exec_prefix);
|
|
} while (exec_prefix[0]);
|
|
|
|
/* Look at configure's EXEC_PREFIX */
|
|
strcpy(exec_prefix, EXEC_PREFIX);
|
|
joinpath(exec_prefix, lib_python);
|
|
joinpath(exec_prefix, "lib-dynload");
|
|
if (isdir(exec_prefix))
|
|
return 1;
|
|
|
|
/* Fail */
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void
|
|
calculate_path()
|
|
{
|
|
extern char *Py_GetProgramName();
|
|
|
|
static char delimiter[2] = {DELIM, '\0'};
|
|
static char separator[2] = {SEP, '\0'};
|
|
char *pythonpath = PYTHONPATH;
|
|
char *rtpypath = getenv("PYTHONPATH");
|
|
char *home = Py_GetPythonHome();
|
|
char *path = getenv("PATH");
|
|
char *prog = Py_GetProgramName();
|
|
char argv0_path[MAXPATHLEN+1];
|
|
int pfound, efound; /* 1 if found; -1 if found build directory */
|
|
char *buf;
|
|
int bufsz;
|
|
int prefixsz;
|
|
char *defpath = pythonpath;
|
|
|
|
/* Initialize this dynamically for K&R C */
|
|
sprintf(lib_python, "lib/python%s", VERSION);
|
|
|
|
/* 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 (strchr(prog, SEP))
|
|
strcpy(progpath, prog);
|
|
else if (path) {
|
|
while (1) {
|
|
char *delim = strchr(path, DELIM);
|
|
|
|
if (delim) {
|
|
int len = delim - path;
|
|
strncpy(progpath, path, len);
|
|
*(progpath + len) = '\0';
|
|
}
|
|
else
|
|
strcpy(progpath, path);
|
|
|
|
joinpath(progpath, prog);
|
|
if (isxfile(progpath))
|
|
break;
|
|
|
|
if (!delim) {
|
|
progpath[0] = '\0';
|
|
break;
|
|
}
|
|
path = delim + 1;
|
|
}
|
|
}
|
|
else
|
|
progpath[0] = '\0';
|
|
|
|
strcpy(argv0_path, progpath);
|
|
|
|
#if HAVE_READLINK
|
|
{
|
|
char tmpbuffer[MAXPATHLEN+1];
|
|
int linklen = readlink(progpath, tmpbuffer, MAXPATHLEN);
|
|
while (linklen != -1) {
|
|
/* It's not null terminated! */
|
|
tmpbuffer[linklen] = '\0';
|
|
if (tmpbuffer[0] == SEP)
|
|
strcpy(argv0_path, tmpbuffer);
|
|
else {
|
|
/* Interpret relative to progpath */
|
|
reduce(argv0_path);
|
|
joinpath(argv0_path, tmpbuffer);
|
|
}
|
|
linklen = readlink(argv0_path, tmpbuffer, MAXPATHLEN);
|
|
}
|
|
}
|
|
#endif /* HAVE_READLINK */
|
|
|
|
reduce(argv0_path);
|
|
|
|
if (!(pfound = search_for_prefix(argv0_path, home))) {
|
|
if (!Py_FrozenFlag)
|
|
fprintf(stderr,
|
|
"Could not find platform independent libraries <prefix>\n");
|
|
strcpy(prefix, PREFIX);
|
|
joinpath(prefix, lib_python);
|
|
}
|
|
else
|
|
reduce(prefix);
|
|
|
|
if (!(efound = search_for_exec_prefix(argv0_path, home))) {
|
|
if (!Py_FrozenFlag)
|
|
fprintf(stderr,
|
|
"Could not find platform dependent libraries <exec_prefix>\n");
|
|
strcpy(exec_prefix, EXEC_PREFIX);
|
|
joinpath(exec_prefix, "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)
|
|
bufsz += strlen(rtpypath) + 1;
|
|
|
|
prefixsz = strlen(prefix) + 1;
|
|
|
|
while (1) {
|
|
char *delim = strchr(defpath, DELIM);
|
|
|
|
if (defpath[0] != SEP)
|
|
/* Paths are relative to prefix */
|
|
bufsz += prefixsz;
|
|
|
|
if (delim)
|
|
bufsz += delim - defpath + 1;
|
|
else {
|
|
bufsz += strlen(defpath) + 1;
|
|
break;
|
|
}
|
|
defpath = delim + 1;
|
|
}
|
|
|
|
bufsz += strlen(exec_prefix) + 1;
|
|
|
|
/* This is the only malloc call in this file */
|
|
buf = malloc(bufsz);
|
|
|
|
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 = PYTHONPATH;
|
|
}
|
|
else {
|
|
/* Run-time value of $PYTHONPATH goes first */
|
|
if (rtpypath) {
|
|
strcpy(buf, rtpypath);
|
|
strcat(buf, delimiter);
|
|
}
|
|
else
|
|
buf[0] = '\0';
|
|
|
|
/* Next goes merge of compile-time $PYTHONPATH with
|
|
* dynamically located prefix.
|
|
*/
|
|
defpath = pythonpath;
|
|
while (1) {
|
|
char *delim = strchr(defpath, DELIM);
|
|
|
|
if (defpath[0] != SEP) {
|
|
strcat(buf, prefix);
|
|
strcat(buf, separator);
|
|
}
|
|
|
|
if (delim) {
|
|
int len = delim - defpath + 1;
|
|
int end = strlen(buf) + len;
|
|
strncat(buf, defpath, len);
|
|
*(buf + end) = '\0';
|
|
}
|
|
else {
|
|
strcat(buf, defpath);
|
|
break;
|
|
}
|
|
defpath = delim + 1;
|
|
}
|
|
strcat(buf, delimiter);
|
|
|
|
/* Finally, on goes the directory for dynamic-load modules */
|
|
strcat(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);
|
|
}
|
|
else
|
|
strcpy(prefix, PREFIX);
|
|
|
|
if (efound > 0) {
|
|
reduce(exec_prefix);
|
|
reduce(exec_prefix);
|
|
reduce(exec_prefix);
|
|
}
|
|
else
|
|
strcpy(exec_prefix, EXEC_PREFIX);
|
|
}
|
|
|
|
|
|
/* External interface */
|
|
|
|
char *
|
|
Py_GetPath()
|
|
{
|
|
if (!module_search_path)
|
|
calculate_path();
|
|
return module_search_path;
|
|
}
|
|
|
|
char *
|
|
Py_GetPrefix()
|
|
{
|
|
if (!module_search_path)
|
|
calculate_path();
|
|
return prefix;
|
|
}
|
|
|
|
char *
|
|
Py_GetExecPrefix()
|
|
{
|
|
if (!module_search_path)
|
|
calculate_path();
|
|
return exec_prefix;
|
|
}
|
|
|
|
char *
|
|
Py_GetProgramFullPath()
|
|
{
|
|
if (!module_search_path)
|
|
calculate_path();
|
|
return progpath;
|
|
}
|