.\" Copyright (c) 1983, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#) random. 3 8.1 (Berkeley) 6/4/93 .\" %FreeBSD: src/lib/libc/stdlib/random. 3, v 1.11. 2.5 2001/12/14 18:33:58 ru Exp % .\" $FreeBSD: doc/ja_JP.eucJP/man/man3/random. 3, v 1.4 2002/05/18 07:12:56 horikawa Exp $ .\" .Dd June 4, 1993 .Dt RANDOM 3 .Os .Sh ¸íĪ .Nm random , .Nm srandom , .Nm srandomdev , .Nm initstate , .Nm setstate .Nd ¶Ù¾î³­ ³­¼ö Á¦³×·¹ÀÌÅÍ, ¹× Á¦³×·¹ÀÌÅ͸¦ º¯°æÇÏ´Â routine .Sh ÇÁ·Î±×·¥ ¶óÀ̺귯¸® .Lb libc .Sh ¼­½Ä .In stdlib.h .Ft long .Fn random void .Ft void .Fn srandom "unsigned long seed" .Ft void .Fn srandomdev void .Ft char * .Fn initstate "unsigned long seed" "char *state" "long n" .Ft char * .Fn setstate "char *state" .Sh ÇØ¼³ .Fn random ÇÔ¼ö´Â, ºñ¼±Çü °¡¹ý Çǵå¹é ³­¼ö Á¦³×·¹ÀÌÅ͸¦ »ç¿ëÇØ, µðÆúÆ®·Î »çÀÌÁî°¡ 31 ÀÇ, ·Õ Á¤¼öÀÇ Å×À̺íÀ» ä¿ëÇØ, 0 À¸·ÎºÎÅÍ .if t 2\u\s731\s10\d\(mi1 .if n (2**31)\(mi1 ±îÁöÀÇ ¹üÀ§¿¡¼­ ¿¬¼ÓÇÑ À¯»ç ³­¼ö¸¦ µÇµ¹¸³´Ï´Ù. ÀÌ ³­¼ö Á¦³×·¹ÀÌÅÍÀÇ ÁÖ±â´Â ¸Å¿ì Å©°í, ¾à .if t 16\(mu(2\u\s731\s10\d\(mi1) .if n 16*((2**31)\(mi1) ÀÔ´Ï´Ù. .Pp .Fn random ÇÔ¼ö¿Í .Fn srandom ÇÔ¼öÀÇ È£Ãâ ¼ø¼­¿Í ÃʱâÈ­ ÇÁ·ÎÆÛƼ´Â, .Xr rand 3 ÇÔ¼ö¿Í .Xr srand 3 ÇÔ¼öÀÇ °Í°ú (´ëü·Î) °°½À´Ï´Ù. Â÷ÀÌ´Â, .Xr rand 3 ÇÏÁö¸¸ ÀÛ¼ºÇÏ´Â ·£´ý½ÃÄö½º°¡ ²Ï µÚ¶³¾îÁø °ÍÀÎ °ÍÀÔ´Ï´Ù. ½ÇÁ¦, rand °¡ ÀÛ¼ºÇÏ´Â ÇÏÀ§°¡ ¸¹Àº ºñÆ®´Â, ¼øÈ¯ ÆÐÅÏÀÌ µË´Ï´Ù. .Fn random ÇÏÁö¸¸ ÀÛ¼ºÇÏ´Â ºñÆ®´Â ¸ðµÎ »ç¿ëÇÒ ¼ö ÀÖ½À´Ï´Ù. ¿¹¸¦ µé¾î .Sq Li random()&01 ±×·³, ·£´ýÀÎ ¹ÙÀ̳ʸ®Ä¡°¡ ÀÛ¼ºµË´Ï´Ù. .Pp .Xr rand 3 (¿Í)°ú °°ÀÌ, .Fn random (Àº)´Â ¼öÄ¡ÀÇ ¼øÂ÷ ¼ø¼­¸¦ µðÆúÆ®·Î ÀÛ¼ºÇÕ´Ï´Ù. ÀÌ ¼øÂ÷ ¼ø¼­´Â, Á¾À» .Ql 1 (À¸)·Î ÇØ .Fn srandom (À»)¸¦ È£ÃâÇϸé(ÀÚ) ÀçÀÛ¼ºÇÒ ¼ö ÀÖ½À´Ï´Ù. .Pp .Fn srandomdev routine´Â, ¾Ïȣȭ¿¡¼­ÀÇ »ç¿ë¿¡ ÀûÀýÇÑ ³­¼ö¸¦ µÇµ¹¸°´Ù .Xr urandom 4 ³­¼ö µð¹ÙÀ̽º¸¦ »ç¿ëÇØ, »óÅ ¹è¿­À» ÃʱâÈ­ÇÕ´Ï´Ù. ÀÌ ÃʱâÈ­ ÇÁ·Î½ÃÀú´Â, ¾î¶°ÇÑ °ªÀ¸·Î .Fn srandom (À»)¸¦ È£ÃâÇØµµ ÀçÀÛ¼ºÇÒ ¼ö ¾ø´Â »óŸ¦ ÀÛ¼ºÇÏ´Â °Í¿¡ ÁÖÀÇÇØ ÁÖ¼¼¿ä. »óÅ ¹öÆÛ³»°¡ ¿¬¼ÓÇÏ´Â Ç×Àº, °íÁ¤ÀÇ Á¾ÀÇ °æ¿ì¿¡ Àû¿ëµÈ´Ù LC ¾Ë°í¸®Áò¿¡¼­´Â µµÃâÇÒ ¼ö ¾ø±â ¶§¹®ÀÔ´Ï´Ù. .Pp .Fn initstate routine´Â, Àμö·Î¼­ °Ç³×¹ÞÀº »óÅ ¹è¿­À», ÈÄÀÇ »ç¿ëÀ» À§Çؼ­(¶§¹®¿¡) ÃʱâÈ­ÇÕ´Ï´Ù. .Fn initstate (Àº)´Â, »óÅ ¹è¿­ÀÇ »çÀÌÁî (¹ÙÀÌÆ® ´ÜÀ§)¸¦ »ç¿ëÇØ, ³­¼ö Á¦³×·¹ÀÌÅÍÀÇ º¹ÀâÇÔÀ» °áÁ¤ÇÕ´Ï´Ù. »óŸ¦ Å©°Ô Çϸé(ÀÚ), ³­¼öÀÇ ÁúÀº ¿À¸¨´Ï´Ù. (ÇöÀç·Î¼­´Â, »óÅ Á¤º¸ÀÇ ¾ç¿¡ ¡¸ÃÖÀû¡¹ÀÎ °ªÀº, 8 ¹ÙÀÌÆ®, 32 ¹ÙÀÌÆ®, 64 ¹ÙÀÌÆ®, 128 ¹ÙÀÌÆ®, 256 ¹ÙÀÌÆ®ÀÔ´Ï´Ù. ±× ¿ÜÀÇ °ªÀº, °¡Àå °¡±î¿î °ª¿¡ ÀÎÇÏÇÒ ¼ö ÀÖ½À´Ï´Ù. 8 ¹ÙÀÌÆ®º¸´Ù ÀÛÀº °ªÀ» »ç¿ëÇϸé(ÀÚ) ¿¡·¯°¡ µË´Ï´Ù. ) ÃʱâÈ­ÀÇ Á¾ (³­¼ö ¼øÂ÷ ¼ø¼­ÀÇ °³½ÃÁ¡À» ÁöÁ¤ÇØ, °°Àº Á¡À¸·ÎºÎÅÍ Àç°³ÇÒ ¼ö ÀÖ´Ù)µµ ÀμöÀÔ´Ï´Ù. .Fn initstate ÇÔ¼ö´Â, ÀÌÀü »óÅ Á¤º¸ ¹è¿­¿¡ÀÇ Æ÷ÀÎÅ͸¦ µÇµ¹¸³´Ï´Ù. .Pp »óŸ¦ ÃʱâÈ­Çϸé(ÀÚ), .Fn setstate routine·Î »óŸ¦ Àçºü¸£°Ô ±³Ã¼µË´Ï´Ù. .Fn setstate ÇÔ¼ö´Â, ÀÌÀü »óÅ ¹è¿­¿¡ÀÇ Æ÷ÀÎÅ͸¦ µÇµ¹¸³´Ï´Ù. ÀμöÀÎ »óÅ ¹è¿­Àº, ´ÙÀ½¿¡ .Fn initstate Àΰ¡ .Fn setstate (À»)¸¦ È£ÃâÇÒ ¶§±îÁö, ÇÑÃþ ´õ ³­¼ö¸¦ ÀÛ¼ºÇϴµ¥ »ç¿ëµË´Ï´Ù. .Pp »óÅ ¹è¿­À» ÃʱâÈ­Çϸé(ÀÚ), .Fn initstate (À»)¸¦ (¸ñÀûÀÇ Á¾, »óÅ ¹è¿­, »çÀÌÁî·Î) È£ÃâÇÏ´ÂÁö, ȤÀº (»óÅ ¹è¿­À» ÁöÁ¤Çß´Ù) .Fn setstate (¿Í)°ú (¸ñÀûÀÇ Á¾À» ÁöÁ¤Çß´Ù) .Fn srandom ÀÇ ¾çÂÊ ¸ðµÎ¸¦ È£ÃâÇÏ´Â °ÍÀ¸·Î, ´Ù¸¥ Á¡À¸·ÎºÎÅÍ Àç°³ÇÒ ¼ö ÀÖ½À´Ï´Ù. .Fn setstate (¿Í)°ú .Fn srandom ÀÇ ¾çÂÊ ¸ðµÎ¸¦ È£ÃâÇϸé(ÀÚ), »óÅ ¹è¿­ÀÇ »çÀÌÁ ÃʱâÈ­ÇÑ ´ÙÀ½¿¡ ±â¾ïÇÒ Çʿ䰡 ¾ø´Ù ±×·¸´Ù°í ÇÏ´Â ÀåÁ¡À» ¾òÀ» ¼ö ÀÖ½À´Ï´Ù. .Pp »óÅ Á¤º¸¸¦ 256 ¹ÙÀÌÆ®·Î Çϸé(ÀÚ), ³­¼ö Á¦³×·¹ÀÌÅÍÀÇ ÁÖ±â´Â .if t 2\u\s769\s10\d .if n 2**69 º¸´Ù Ä¿Áý´Ï´Ù. ÀÌ ÁÖ±â·Î´Â, ´ëºÎºÐÀÇ ¸ñÀûÀ¸·Î ÃæºÐÈ÷ ´ëÀÀÇÒ ¼ö ÀÖ½À´Ï´Ù. .Sh ÀúÀÚ .An Earl T. Cohen .Sh Áø´Ü »óÅ Á¤º¸¸¦ 8 ¹ÙÀÌÆ®º¸´Ù ÀÛ°Ô ÇØ .Fn initstate (À»)¸¦ È£ÃâÇϰųª »óÅ Á¤º¸°¡ »ß¶Ô¾îÁø °ÍÀ» .Fn setstate ÇÏÁö¸¸ °ËÃâÇϰųª Çϸé(ÀÚ), ¿¡·¯ ¸Þ¼¼Áö°¡ Ç¥ÁØ ¿¡·¯ Ãâ·Â¿¡ Ãâ·ÂµË´Ï´Ù. .Sh °ü·Ã Ç׸ñ .Xr rand 3 , .Xr srand 3 , .Xr urandom 4 .Sh ¿ª»ç ÀÌ ÇÔ¼ö´Â, .Bx 4.2 ±×¸®°í µîÀåÇß½À´Ï´Ù. .Sh ¹ö±× ó¸® ¼Óµµ´Â, .Xr rand 3 ÀÇ ¾à 2/3 ÀÔ´Ï´Ù. .Pp ³°Àº ½ÇÀå¿¡¼­´Â ÃʱâÈ­ÀÇ ÇÁ·Î¼¼½º°¡ ¸Å¿ì ¾àÇϰí, Á¾À» ÀÌ¿ëÇØµµ ·£´ý½ÃÄö½º´Â ±×´ÙÁö ¹Ù²îÁö ¾Ê¾Ò½À´Ï´Ù. ÇöÀçÀÇ ½Ã½ºÅÛÀº, º¸´Ù ÁÁÀº À¯»ç ³­¼ö Á¦³×·¹ÀÌÅ͸¦ Ãʱ⠻óÅÂÀÇ »êÃâ¿¡ ä¿ëÇϰí ÀÖ½À´Ï´Ù.