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realpath

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realpath - Àµµ¬²½¤µ¤ì¤¿ÀäÂХѥ¹Ì¾¤òÊÖ¤¹

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#include <limits.h>

#include <stdlib.h>



char *realpath(const char *path, char *resolved_path);

 

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¤½¤ì°Ê³°¤Î¾ì¹ç¤Ï¡¢¥Ì¥ë (NULL) ¥Ý¥¤¥ó¥¿¡¼¤¬Ê֤ꡢÇÛÎó resolved_path ¤ÎÆâÍƤÏÉÔÄê¤Ç¤¢¤ë¡£ ¥°¥í¡¼¥Ð¥ëÊÑ¿ô errno ¤¬¥¨¥é¡¼¤ÎÆâÍƤˤ¢¤ï¤»¤Æ¥»¥Ã¥È¤µ¤ì¤ë¡£

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EACCES

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EINVAL

path ¤« resolved_path ¤Î¤¤¤º¤ì¤«¤¬ NULL ¤Ç¤¢¤ë¡£ (libc5 ¤Ç¤Ï¡¢¤³¤Î¤è¤¦¤Ê¾ì¹ç segfault ¤òµ¯¤³¤¹¤À¤±¤Ç¤¢¤í¤¦) ⤷¡¢²¼µ­¤Î¡ÖÃí°Õ¡×¤ÎÀá¤ò»²¾È¤Î¤³¤È¡£

EIO

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ELOOP

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ENAMETOOLONG

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ENOENT

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ENOTDIR

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¤³¤Î´Ø¿ô¤¬ Linux ¤ËÅо줷¤¿¤Î¤Ï libc 4.5.21 ¤Ç¤¢¤ë¡£

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4.4BSD, POSIX.1-2001.

4.4BSD ¤È Solaris ¤Ç¤Ï¡¢¥Ñ¥¹Ì¾¤ÎŤµ¤Î¾å¸Â¤Ï (<sys/param.h> ¤ÎÃæ¤Ë¤¢¤ë) MAXPATHLEN ¤Ç¤¢¤ë¡£SUSv2 ¤Ç¤Ï PATH_MAX ¤È NAME_MAX ¤¬µ¬Äꤵ¤ì¤Æ¤ª¤ê¡¢ ¤³¤ì¤é¤Ï <limits.h> ¤ÇÄêµÁ¤µ¤ì¤Æ¤¤¤ë¤«¡¢ pathconf(3) ´Ø¿ô¤«¤éÆÀ¤é¤ì¤ë¡£°Ê²¼¤Î¤è¤¦¤Ê¥½¡¼¥¹¥³¡¼¥É¤Ë¤Ê¤Ã¤Æ¤¤¤ë¤³¤È¤¬Â¿¤¤ (¥Ð¥°¤Î¾Ï¤â»²¾È¤Î¤³¤È) :

#ifdef PATH_MAX

  path_max = PATH_MAX;

#else

  path_max = pathconf(path, _PC_PATH_MAX);

  if (path_max <= 0)

         path_max = 4096;

#endif

4.4BSD¡¢Linux¡¢SUSv2 ¤Ç¤Ï¡¢ÊÖ¤êÃͤϾï¤ËÀäÂХѥ¹Ì¾¤Ç¤¢¤ë¡£ Solaris ¤Ç¤Ï¡¢ °ú¤­¿ô path ¤¬ÁêÂХѥ¹¤Î¾ì¹ç¡¢ÊÖ¤êÃͤ¬ÁêÂХѥ¹¤Ë¤Ê¤ë¤³¤È¤¬¤¢¤ë¡£ realpath() ¤Î¥×¥í¥È¥¿¥¤¥×Àë¸À¤Ï¡¢ libc4 ¤È libc5 ¤Ç¤Ï <unistd.h> ¤Ë¤¢¤ë¤¬¡¢ ¤½¤ì°Ê³°¤Î´Ä¶­¤Ç¤Ï¤¤¤º¤ì¤â <stdlib.h> ¤Ë¤¢¤ë¡£

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realpath() ¤Î glibc ¤Î¼ÂÁõ¤Ç¤ÏÈóɸ½à¤Î³ÈÄ¥¤¬¤Ê¤µ¤ì¤Æ¤¤¤ë¡£ resolved_path ¤Ë NULL ¤¬»ØÄꤵ¤ì¤ë¤È¡¢ realpath() ¤Ï malloc(3) ¤ò»È¤Ã¤Æ²ò·è¤·¤¿¥Ñ¥¹Ì¾¤òÊÝ»ý¤¹¤ë¤¿¤á¤Î¥Ð¥Ã¥Õ¥¡¤ò ºÇÂç¤Ç PATH_MAX ¥Ð¥¤¥È¤Þ¤Ç³ä¤êÅö¤Æ¡¢ ¤³¤Î¥Ð¥Ã¥Õ¥¡¤Ø¤Î¥Ý¥¤¥ó¥¿¤òÊÖ¤¹¡£ ¸Æ¤Ó½Ð¤·¸µ¤Ï¡¢ free(3) ¤ò»È¤Ã¤Æ¤³¤Î¥Ð¥Ã¥Õ¥¡¤ò²òÊü¤¹¤Ù¤­¤Ç¤¢¤ë¡£

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¤³¤Î´Ø¿ô¤Î»ÈÍѤÏÈò¤±¤ë¤³¤È¡£Àß·×Ãʳ¬¤«¤éÌäÂ꤬¤¢¤ë¤«¤é¤À¡£ (Èóɸ½à¤Î resolved_path == NULL ¤Î³ÈÄ¥µ¡Ç½¤ò»È¤ï¤Ê¤¤¸Â¤ê) ½ÐÎϥХåե¡ resolved_path ¤ÎŬÀڤʥµ¥¤¥º¤ò·èÄꤹ¤ë¤³¤È¤¬¤Ç¤­¤Ê¤¤¤«¤é¤Ç¤¢¤ë¡£ POSIX ¤Ç¤Ï¥Ð¥Ã¥Õ¥¡¡¦¥µ¥¤¥º¤È¤·¤Æ PATH_MAX ¤Ï½½Ê¬¤À¤È¤µ¤ì¤Æ¤¤¤ë¤¬¡¢ PATH_MAX ¤ÏÄêµÁºÑ¤ÎÄê¿ô¤Ç¤¢¤ëɬÍפϤʤ¯¡¢ pathconf(3) ¤ò»È¤Ã¤ÆÆÀ¤é¤ì¤ëÃͤǤ¢¤Ã¤Æ¤â¤è¤¤¤³¤È¤Ë¤Ê¤Ã¤Æ¤¤¤ë¡£ pathconf(3) ¤«¤é¥Ð¥Ã¥Õ¥¡¡¦¥µ¥¤¥º¤ò¼èÆÀ¤·¤¿¤È¤·¤Æ¤âɬ¤º¤·¤â½½Ê¬¤Ç¤Ï¤Ê¤¤¡£ ¤Ê¤¼¤Ê¤é¡¢ pathconf(3) ¤ÎÊÖ¤êÃͤ¬Â礭²á¤®¤ÆŬÀڤ˥á¥â¥ê¤ò³ÎÊݤ¹¤ë¤³¤È¤¬¤Ç¤­¤Ê¤¤¤«¤â¤·¤ì¤Ê¤¤ ¤È POSIX ¤Ç¤Ï·Ù¹ð¤µ¤ì¤Æ¤¤¤ë¤·¡¢ pathconf(3) ¤Ï PATH_MAX ¤ËÀ©¸Â¤¬¤Ê¤¤¤³¤È¤ò¼¨¤¹ -1 ¤òÊÖ¤¹¤«¤â¤·¤ì¤Ê¤¤¤«¤é¤Ç¤¢¤ë¡£

libc4 ¤È libc5 ¤Î¼ÂÁõ¤Ï¥Ð¥Ã¥Õ¥¡¡¦¥ª¡¼¥Ð¡¼¥Õ¥í¡¼¤Î²ÄǽÀ­¤ò»ý¤Ã¤Æ¤¤¤ë (libc-5.4.13 ¤Ç½¤Àµ¤µ¤ì¤¿¤¬)¡£¤·¤¿¤¬¤Ã¤Æ¡¢mount ¤Î¤è¤¦¤Ê set-user-ID ¤µ¤ì¤ë¥×¥í¥°¥é¥à¤Ç¤Ï¡¢¤³¤Î´Ø¿ôÁêÅö¤Î´Ø¿ô¤ò¼«Á°¤Ç»ý¤ÄɬÍפ¬¤¢¤ë¡£

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readlink(2), canonicalize_file_name(3), getcwd(3), pathconf(3), sysconf(3)