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author | Guido van Rossum <guido@python.org> | 1994-10-05 16:13:01 (GMT) |
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committer | Guido van Rossum <guido@python.org> | 1994-10-05 16:13:01 (GMT) |
commit | d8336c2286f647b4bba34a39c18fd1ae859da92e (patch) | |
tree | e9f893992b83bd78e878834370d104a321f1bf74 /Tools/freeze/README | |
parent | ca9321e6d0794cc52cddbbbcc86f6cc98e8b46af (diff) | |
download | cpython-d8336c2286f647b4bba34a39c18fd1ae859da92e.zip cpython-d8336c2286f647b4bba34a39c18fd1ae859da92e.tar.gz cpython-d8336c2286f647b4bba34a39c18fd1ae859da92e.tar.bz2 |
Lots of things added. README written (mostly).
Diffstat (limited to 'Tools/freeze/README')
-rw-r--r-- | Tools/freeze/README | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/Tools/freeze/README b/Tools/freeze/README new file mode 100644 index 0000000..9ab900f --- /dev/null +++ b/Tools/freeze/README @@ -0,0 +1,161 @@ +THE FREEZE SCRIPT +================= + + +What is Freeze? +--------------- + +Freeze make it possible to ship arbitrary Python programs to people +who don't have Python. The shipped file (called a "frozen" version of +your Python program) is an executable, so this only works if your +platform is compatible with that on the receiving end (this is usually +a matter of having the same major operating system revision and CPU +type). + +The shipped file contains a Python interpreter and large portions of +the Python run-time. Some measures have been taken to avoid linking +unneeded modules, but the resulting binary is usually not small. + +The Python source code of your program (and of the library modules +written in Python that it uses) is not included in the binary -- +instead, the compiled byte-code (the instruction stream used +internally by the interpreter) is incorporated. This gives some +protection of your Python source code, though not much -- a +disassembler for Python byte-code is available in the standard Python +library. At least someone running "strings" on your binary won't see +the source. + + +How does Freeze know which modules to include? +---------------------------------------------- + +Freeze uses a pretty simple-minded algorithm to find the modules that +your program uses: given a file containing Python source code, it +scans for lines beginning with the word "import" or "from" (possibly +preceded by whitespace) and then it knows where to find the module +name(s) in those lines. It then recursively scans the source for +those modules (if found, and not already processed) in the same way. + +Freeze will not see import statements hidden behind another statement, +like this: + + if some_test: import M # M not seen + +or like this: + + import A; import B; import C # B and C not seen + +nor will it see import statements constructed using string +operations and passed to 'exec', like this: + + exec "import %s" % "M" # M not seen + +On the other hand, Freeze will think you are importing a module even +if the import statement it sees will never be executed, like this: + + if 0: + import M # M is seen + +One tricky issue: Freeze assumes that the Python interpreter and +environment you're using to run Freeze is the same one that would be +used to run your program, which should also be the same whose sources +and installed files you will learn about in the next section. In +particular, your PYTHONPATH setting should be the same as for running +your program locally. (Tip: if the program doesn't run when you type +"python hello.py" there's little chance of getting the frozen version +to run.) + + +How do I use Freeze? +-------------------- + +Ideally, you should be able to use it as follows: + + python freeze.py hello.py + +where hello.py is your program and freeze.py is the main file of +Freeze (in actuality, you'll probably specify an absolute pathname +such as /ufs/guido/src/python/Demo/freeze/freeze.py). + +Unfortunately, this doesn't work. Well, it might, but somehow it's +extremely unlikely that it'll work on the first try. (If it does, +skip to the next section.) Most likely you'll get this error message: + + needed directory /usr/local/lib/python/lib not found + +The reason is that Freeze require that some files that are normally +kept inside the Python build tree are installed, and it searches for +it in the default install location. (The default install prefix is +/usr/local; these particular files are installed at lib/python/lib +under the install prefix.) + +The particular set of files needed is installed only if you run "make +libainstall" (note: "liba", not "lib") in the Python build tree (which +is the tree where you build Python -- often, but not necessarily, this +is also the Python source tree). If you have in fact done a "make +libainstall" but used a different prefix, all you need to do is pass +that same prefix to Freeze with the -p option: + + python freeze.py -p your-prefix hello.py + +(If you haven't run "make libainstall" yet, go and do it now and don't +come back until you've done it.) + + +How do I configure Freeze? +-------------------------- + +It's a good idea to change the line marked with XXX in freeze.py (an +assignment to variable PACK) to point to the absolute pathname of the +directory where Freeze lives (Demo/freeze in the Python source tree.) +This makes it possible to call Freeze from other directories. + +You can also edit the assignment to variable PREFIX -- this saves a +lot of -p options. + + +How do I use Freeze with extensions modules? +-------------------------------------------- + +XXX to be written. (In short: pass -e extensionbuilddir.) + + +How do I use Freeze with dynamically loaded extension modules? +-------------------------------------------------------------- + +XXX to be written. (In short: pass -e modulebuilddir -- this even +works if you built the modules in Python's own Modules directory.) + + + +What do I do next? +------------------ + +Freeze creates three files: frozen.c, config.c and Makefile. To +produce the frozen version of your program, you can simply type +"make". This should produce a binary file. If the filename argument +to Freeze was "hello.py", the binary will be called "hello". On the +other hand, if the argument was "hello", the binary will be called +"hello.bin". If you passed any other filename, all bets are off. :-) +In any case, the name of the file will be printed as the last message +from Freeze. + + +Help! I've tried everything but it doesn't work! +------------------------------------------------- + +Freeze is currently beta software. You could email me a bug report. +Please give as much context as possible -- "Freeze doesn't work" is +not going to get much sympathy. You could fix the bug and send me a +patch. You could learn Tcl. + +If you are thinking about debugging Freeze, start playing with a +really simple program first (like "print 'hello world'"). If you +can't get that to work there's something fundamentally wrong with your +environment (or with your understanding of it). Gradually build it up +to use more modules and extensions until you find where it stops +working. After that, you're on your own -- happy hacking! + + +--Guido van Rossum, CWI, Amsterdam <mailto:Guido.van.Rossum@cwi.nl> +<http://www.cwi.nl/cwi/people/Guido.van.Rossum.html> |