A Sauerbraten map file parser/trimmer. Feed it a gunzipped .ogz file and it gives you a file containing only the header, game identifier, and entities sections. (You'll have to gzip that file back up in order to use it as an .ogz file on the server. See: genall.sh)
It specifically omits the map vars, extras, MRU ("most recently used"), lightmaps, blendmaps, vslots and octree geometry data from the original file. This reduces the file size by ~99.6%.
You can also use it as a parser of the processed sections, but it can't give you information on vslots, extras, MRU, lightmaps, blendmaps and the octree since it doesn't parse them.
$ genserverogz -help
Reads uncompressed OGZ file on stdin and writes a minimal uncompressed OGZ file containing only the entity data to stdout.
Specify any print flag to only print the requested fields to stdout instead of the shrunk map data.
Usage of genserverogz:
-ents
print map entities
-game
print game identifier
-vars
print map vars (version 29+ only)
-version
print file format version
To analyse a map file:
$ gunzip --suffix=ogz --stdout ~/sauerbraten-code/packages/base/ot.ogz | genserverogz -version -vars -game -ents
OGZ file format version: 33
map variables: (26)
skylight = 10196625
lerpsubdiv = 2
lightlod = 0
waterfog = 20
lighterror = 1
lerpsubdivsize = 4
lerpangle = 44
skyboxcolour = 15466495
causticscale = 40
lightprecision = 42
maptitle = Temple Ot by Nieb & ot4ku
sunlight = 10525590
lavacolour = 16728064
sunlightyaw = 120
sunlightscale = 2
fog = 3000
skytexturelight = 0
skytexture = 0
sunlightpitch = 55
fogcolour = 10984320
watercolour = 48840
ambient = 2432801
yawsky = 120
blurskylight = 2
waterfallcolour = 0
skybox = penguins/yonder
game: fps
map entities: (89)
0: type: 19, attrs: 1 -1 0 0 0, pos: 744.000000 304.000000 580.000000
1: type: 20, attrs: 173 1 1 0 0, pos: 592.000000 624.000000 548.000000
2: type: 1, attrs: 250 80 74 70 0, pos: 664.000000 568.000000 576.000000
3: type: 1, attrs: 250 80 74 70 0, pos: 688.000000 432.000000 576.000000
4: type: 19, attrs: 2 -1 0 0 0, pos: 432.000000 296.000000 516.000000
5: type: 20, attrs: 320 2 1 0 0, pos: 432.000000 304.000000 580.000000
6: type: 1, attrs: 250 80 74 70 0, pos: 408.000000 344.000000 556.000000
7: type: 3, attrs: 269 0 0 0 0, pos: 440.000000 528.000000 548.000000
8: type: 3, attrs: 128 0 0 0 0, pos: 688.000000 576.000000 548.000000
9: type: 3, attrs: 320 0 0 0 0, pos: 496.000000 416.000000 532.000000
10: type: 3, attrs: 18 0 0 0 0, pos: 664.000000 296.000000 580.000000
11: type: 3, attrs: 297 0 0 0 0, pos: 384.000000 320.000000 516.000000
12: type: 1, attrs: 50 10 100 200 0, pos: 432.000000 296.000000 528.000000
13: type: 1, attrs: 60 10 100 200 0, pos: 744.000000 304.000000 592.000000
14: type: 23, attrs: 30 0 0 0 0, pos: 744.000000 496.000000 548.000000
15: type: 1, attrs: 40 10 100 200 0, pos: 736.000000 496.000000 556.000000
16: type: 1, attrs: 15 250 250 240 0, pos: 664.000000 568.000000 588.000000
17: type: 1, attrs: 15 250 250 250 0, pos: 408.000000 344.000000 564.000000
18: type: 10, attrs: 0 0 0 0 0, pos: 604.000000 300.000000 580.000000
19: type: 10, attrs: 0 0 0 0 0, pos: 456.000000 528.000000 628.000000
20: type: 11, attrs: 0 0 0 0 0, pos: 668.000000 420.000000 612.000000
21: type: 8, attrs: 0 0 0 0 0, pos: 436.000000 588.000000 548.000000
22: type: 8, attrs: 0 0 0 0 0, pos: 444.000000 372.000000 516.000000
23: type: 8, attrs: 0 0 0 0 0, pos: 660.000000 596.000000 548.000000
24: type: 14, attrs: 0 0 0 0 0, pos: 496.000000 528.000000 532.000000
25: type: 11, attrs: 0 0 0 0 0, pos: 484.000000 380.000000 580.000000
26: type: 17, attrs: 0 0 0 0 0, pos: 664.000000 496.000000 612.000000
27: type: 16, attrs: 0 0 0 0 0, pos: 584.000000 330.000000 532.000000
28: type: 9, attrs: 0 0 0 0 0, pos: 380.000000 404.000000 516.000000
29: type: 14, attrs: 0 0 0 0 0, pos: 724.000000 344.000000 548.000305
30: type: 14, attrs: 0 0 0 0 0, pos: 652.000000 552.000000 564.000000
31: type: 1, attrs: 100 60 57 56 0, pos: 592.000000 624.000000 560.000000
32: type: 2, attrs: 90 11 0 0 0, pos: 363.894836 364.000000 527.999451
33: type: 2, attrs: 90 11 0 0 0, pos: 363.896301 332.000000 527.987000
34: type: 1, attrs: 15 255 250 250 0, pos: 688.000000 432.000000 588.000000
35: type: 1, attrs: 12 250 225 200 0, pos: 444.000000 372.000000 516.000000
36: type: 1, attrs: 12 250 225 200 0, pos: 380.000000 404.000000 516.000000
37: type: 1, attrs: 12 250 225 200 0, pos: 436.000000 588.000000 548.000000
38: type: 1, attrs: 12 250 225 200 0, pos: 484.000000 380.000000 580.000000
39: type: 1, attrs: 12 250 225 200 0, pos: 604.000000 300.000000 580.000000
40: type: 1, attrs: 12 250 225 200 0, pos: 660.000000 596.000000 548.000000
41: type: 1, attrs: 12 250 225 200 0, pos: 668.000000 420.000000 612.000000
42: type: 2, attrs: 195 14 0 0 0, pos: 600.657227 584.657593 511.551697
43: type: 2, attrs: 195 14 0 0 0, pos: 624.110901 392.000000 511.956787
44: type: 2, attrs: 90 11 0 0 0, pos: 363.908356 348.000000 528.007812
45: type: 1, attrs: 60 60 59 58 0, pos: 736.000000 496.000000 608.000000
46: type: 3, attrs: 132 0 0 0 0, pos: 676.000000 588.000000 548.000000
47: type: 3, attrs: 359 0 0 0 0, pos: 500.000000 308.000000 580.000000
48: type: 3, attrs: 114 0 0 0 0, pos: 700.000000 556.000000 612.000000
49: type: 3, attrs: 226 0 0 0 0, pos: 452.000000 572.000000 548.000000
50: type: 3, attrs: 308 0 0 0 0, pos: 400.000000 320.000000 516.000000
51: type: 3, attrs: 90 0 0 0 0, pos: 716.000000 460.000000 612.000000
52: type: 3, attrs: 282 0 0 0 0, pos: 444.000000 364.000000 580.000000
53: type: 3, attrs: 88 0 0 0 0, pos: 686.000000 436.000000 548.000000
54: type: 3, attrs: 221 0 0 0 0, pos: 496.000000 584.000000 532.000000
55: type: 3, attrs: 25 0 0 0 0, pos: 632.000000 296.000000 580.000000
56: type: 3, attrs: 301 0 0 0 0, pos: 384.000000 336.000000 516.000000
57: type: 1, attrs: 12 250 225 200 0, pos: 676.000000 340.000000 548.000000
58: type: 12, attrs: 0 0 0 0 0, pos: 676.000000 340.000000 548.000000
59: type: 14, attrs: 0 0 0 0 0, pos: 426.000000 392.000000 596.000000
60: type: 3, attrs: 20 0 0 0 0, pos: 648.000000 296.000000 580.000000
61: type: 3, attrs: 135 0 0 0 0, pos: 684.000000 584.000000 548.000000
62: type: 3, attrs: 245 0 0 0 0, pos: 444.000000 564.000000 548.000000
63: type: 3, attrs: 259 0 0 0 0, pos: 436.000000 540.000000 548.000000
64: type: 3, attrs: 290 0 0 0 0, pos: 444.000000 376.000000 580.000000
65: type: 3, attrs: 353 0 0 0 0, pos: 486.000000 306.000000 580.000000
66: type: 3, attrs: 65 0 0 0 0, pos: 686.000000 414.000000 548.000000
67: type: 3, attrs: 8 0 0 0 0, pos: 470.000000 318.000000 516.000000
68: type: 3, attrs: 105 0 0 0 0, pos: 692.000000 564.000000 548.000000
69: type: 6, attrs: 0 80 0 0 0, pos: 432.000000 296.000000 512.000000
70: type: 1, attrs: 30 200 180 160 0, pos: 732.000000 340.000000 580.000000
71: type: 1, attrs: 30 200 180 160 0, pos: 732.000000 348.000000 580.000000
72: type: 1, attrs: 30 200 180 160 0, pos: 732.000000 356.000000 580.000000
73: type: 1, attrs: 30 200 180 160 0, pos: 732.000000 364.000000 580.000000
74: type: 7, attrs: 50 0 0 0 0, pos: 734.000000 340.000000 584.000000
75: type: 7, attrs: 50 0 0 0 0, pos: 734.000000 348.000000 584.000000
76: type: 7, attrs: 50 0 0 0 0, pos: 734.000000 356.000000 584.000000
77: type: 7, attrs: 50 0 0 0 0, pos: 734.000000 364.000000 584.000000
78: type: 1, attrs: 30 200 180 160 0, pos: 652.000000 380.000000 580.000000
79: type: 1, attrs: 30 200 180 160 0, pos: 644.000000 380.000000 580.000000
80: type: 7, attrs: 50 0 0 0 0, pos: 652.000000 382.000000 584.000000
81: type: 7, attrs: 50 0 0 0 0, pos: 644.000000 382.000000 584.000000
82: type: 3, attrs: 98 0 0 0 0, pos: 721.892029 352.422546 548.000000
83: type: 1, attrs: 12 250 225 200 0, pos: 496.000000 528.000000 532.000000
84: type: 2, attrs: 270 200 0 0 0, pos: 431.764313 294.000000 528.000000
85: type: 2, attrs: 0 200 0 0 0, pos: 746.000000 304.003906 592.010986
86: type: 2, attrs: 0 194 0 0 0, pos: 736.000000 496.000000 545.000000
87: type: 1, attrs: 12 250 225 200 0, pos: 724.000000 344.000000 548.000000
88: type: 1, attrs: 12 250 225 200 0, pos: 664.000000 496.000000 612.000000
To only generate trimmed map files for use on a server use a script like genall.sh.