pybms is a work in progress BMS (MexScript) parser/interpreter

Motivation for this project is primarily to be functional enough to run some of the hundreds of BMS scripts in applications featuring embedded Python support (Tiled for example) instead of competing with any of the established BMS supporting resource management apps.

Requirements

PLY (so far tested on python 2.7 + PLY 3.4, YMMV)

Demo

Although still missing lots of syntax and features known in other implementations, it can already run some scripts, like this one:

$ cd ~/games/lostvikings/
$ du -b DATA.DAT
1570444 DATA.DAT
$ mkdir pybmsout
$ cd pybmsout
$ bms.py ../The_Lost_Vikings_DAT.bms ../DATA.DAT
...(debug output)
$ for f in $(ls *dat|head); do du -b $f; hexdump -C $f|head -1; done
22018   00000002lOPEUD.dat
00000000  80 15 01 01 01 01 01 01  01 01 01 01 01 01 01 01  |................|
1448    00000003OipWXc.dat
00000000  7f 16 30 ee ff 11 f0 23  f0 35 f0 f0 01 49 00 3b  |..0....#.5...I.;|
51      00000004nU985o.dat
00000000  2f 00 fe ff 3f 3e 3e 3e  2c 00 00 16 ff 16 16 00  |/...?>>>,.......|
412     00000005Q37U_U.dat
00000000  ff 02 59 01 00 f0 12 e0  02 02 1e 40 0c 12 20 bb  |..Y........@.. .|
456     00000006F8494W.dat
00000000  ff 02 a9 01 00 f0 05 10  0c 05 40 02 18 70 0c b9  |..........@..p..|
492     00000007hNbszZ.dat
00000000  ff 02 e9 01 00 f0 09 50  06 09 40 0b 0a 04 7d 0c  |.......P..@...}.|
361     00000008Lz7zVu.dat
00000000  ff 02 79 01 00 f0 10 c0  04 01 0c 04 10 10 d7 0c  |..y.............|
385     00000009ICiFo6.dat
00000000  ff 02 69 01 00 f0 0a 60  02 17 40 0c 01 23 10 93  |..i....`..@..#..|
401     0000000aDZwAqS.dat
00000000  ff 02 6d 01 00 f0 01 02  02 30 0c 04 02 20 7b 04  |..m......0... {.|
296     0000000b72bLiL.dat
00000000  ff 02 d1 01 00 f0 12 f0  19 30 0c 25 40 02 04 ae  |.........0.%@...|

$ cat *dat | md5sum
df0275708f2aa6a95cf71e7295c74a05  -

Then we can compare it to quickbms output running the same script:

$ mkdir ../qbmsout
$ cd ../qbmsout
$ quickbms ../The_Lost_Vikings_DAT.bms ../DATA.DAT
  0000085c 32         00000000.dat
  0000087c 22018      00000001.dat
  00005e7e 1448       00000002.dat
  00006426 51         00000003.dat
  00006459 412        00000004.dat
  ...(~530 files)
  0017f689 4          00000216.dat

Error: incomplete input file number 0, can't read 1 bytes.
  anyway don't worry, it's possible that the BMS script has been written
  to exit in this way if it's reached the end of the archive so check it
  or contact its author or verify that all the files have been extracted

Due to implementation differences first and last block of output are currently different, but with those out of the way, md5sum checks out:

$ cat *dat | md5sum
df0275708f2aa6a95cf71e7295c74a05  -

Also, pybms includes a rudimentary REPL (doesn't yet support multiline statements):

$ rlwrap python bms.py 
> for i = 1 to 5   print "%i%"  next i
1234> set s "asdai9psjdp"
> strlen len s
> print "%len%\n"
11
> help
Available functions (try "HELP func"): 
FOR GET GETVARCHR GOTO IF LOG LOG2 MATH OPEN PRINT PUTVARCHR SAVEPOS SET STRLEN
> help GET
Help on method do_GET in module __main__:

do_GET(self, var, fmt, num) method of __main__.BMSEvaluator instance
    Get VarName Type File

None
>