[c][perl][fseeko64]

perl.hみてたら、なんだ、この最後の64って（いや薄々気づいてたというより書いてあるけどｗ）詳しく知りたくてしらべた。

2453 #ifdef USE_64_BIT_STDIO
2454 #   ifdef HAS_FPOS64_T
2455 #       undef Fpos_t
2456 #       define Fpos_t fpos64_t
2457 #   endif
2458 /* Most 64-bit environments have defines like _LARGEFILE_SOURCE that
2459  * will trigger defines like the ones below.  Some 64-bit environments,
2460  * however, do not. */
2461 #   if defined(USE_FOPEN64)
2462 #       define fopen fopen64
2463 #   endif
2464 #   if defined(USE_FSEEK64)
2465 #       define fseek fseek64 /* don't do fseeko here, see perlio.c */
2466 #   endif
2467 #   if defined(USE_FTELL64)
2468 #       define ftell ftell64 /* don't do ftello here, see perlio.c */
2469 #   endif
2470 #   if defined(USE_FSETPOS64)
2471 #       define fsetpos fsetpos64
2472 #   endif
2473 #   if defined(USE_FGETPOS64)
2474 #       define fgetpos fgetpos64
2475 #   endif
2476 #   if defined(USE_TMPFILE64)
2477 #       define tmpfile tmpfile64
2478 #   endif
2479 #   if defined(USE_FREOPEN64)
2480 #       define freopen freopen64
2481 #   endif
2482 #endif

http://www.c.csce.kyushu-u.ac.jp/kb/wiki/index.php?%A5%D7%A5%ED%A5%B0%A5%E9%A5%DF%A5%F3%A5%B0%2FC%2CC%2B%2B%2F2GB%A4%E8%A4%EA%C2%E7%A4%AD%A4%CA%A5%D5%A5%A1%A5%A4%A5%EB%A4%CE%B0%B7%A4%A4

ああ、なるほど。