Linux Certif

Toute la documentation sur la certification Linux LPI

truncate

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truncate, ftruncate - »ØÄꤷ¤¿Ä¹¤µ¤Ë¥Õ¥¡¥¤¥ë¤òÀÚ¤êµÍ¤á¤ë

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#include <unistd.h>
#include <sys/types.h>

int truncate(const char *path, off_t length);
int ftruncate(int fd, off_t length);

ÀâÌÀ

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¥Õ¥¡¥¤¥ë¥ª¥Õ¥»¥Ã¥È¤ÏÊѹ¹¤µ¤ì¤Ê¤¤¡£

Â礭¤µ¤¬Êѹ¹¤µ¤ì¤ë¤È¡¢¥Õ¥¡¥¤¥ë¤Î st_ctime ¤È st_mtime ¥Õ¥£¡¼¥ë¥É (¤½¤ì¤¾¤ìºÇ½ª¾õÂÖÊѹ¹»þ¹ï¡¢ºÇ½ª½¤Àµ»þ¹ï; stat(2) »²¾È) ¤¬¹¹¿·¤µ¤ì¤ë¡£ ¤Þ¤¿¡¢set-user-ID ¤È set-group-ID ¤Îµö²Ä¥Ó¥Ã¥È¤¬¥¯¥ê¥¢¤µ¤ì¤ë¤«¤â¤·¤ì¤Ê¤¤¡£

ftruncate() ¤Î¾ì¹ç¡¢¥Õ¥¡¥¤¥ë¤Ï½ñ¤­¹þ¤ßÍѤ˳«¤¤¤Æ¤¤¤Ê¤±¤ì¤Ð¤Ê¤é¤Ê¤¤¡£ truncate() ¤Î¾ì¹ç¡¢¥Õ¥¡¥¤¥ë¤Ï½ñ¤­¹þ¤ß²Äǽ¤Ç¤Ê¤±¤ì¤Ð¤Ê¤é¤Ê¤¤¡£

ÊÖ¤êÃÍ

À®¸ù¤·¤¿¾ì¹ç 0 ¤¬Ê֤롣¼ºÇÔ¤·¤¿¾ì¹ç -1 ¤¬Ê֤ꡢ errno ¤¬¥¨¥é¡¼¤ÎÆâÍƤ˽¾¤Ã¤ÆÀßÄꤵ¤ì¤ë¡£

¥¨¥é¡¼

truncate() ¤Ç¤Ï°Ê²¼¤Î¥¨¥é¡¼¥³¡¼¥É¤¬ÄêµÁ¤µ¤ì¤Æ¤¤¤ë¡£

EACCES

¥Ñ¥¹¤Ç»ØÄꤵ¤ì¤Æ¤¤¤ë¥Ç¥£¥ì¥¯¥È¥ê¤Ë¸¡º÷µö²Ä¤Î¤Ê¤¤¤â¤Î¤¬¤¢¤ë (ÌõÃí:x ¥Ó¥Ã¥È¤¬Î©¤Ã¤Æ¤¤¤Ê¤¤)¡£ ¤¢¤ë¤¤¤Ï¡¢»ØÄꤵ¤ì¤¿¥Õ¥¡¥¤¥ë¤ËÂФ¹¤ë½ñ¤­¹þ¤ßµö²Ä¤ò»ý¤Ã¤Æ¤¤¤Ê¤¤¡£ (path_resolution(7) ¤â»²¾È¤Î¤³¤È)

EFAULT

path ¤¬¥×¥í¥»¥¹¤Ë³ä¤êÅö¤Æ¤é¤ì¤Æ¤¤¤ë¥¢¥É¥ì¥¹¶õ´Ö³°¤ò»Ø¤·¤Æ¤¤¤ë¡£

EFBIG

°ú¤­¿ô length ¤¬ºÇÂç¥Õ¥¡¥¤¥ë¥µ¥¤¥º¤è¤êÂ礭¤¤¡£(XSI)

EINTR

¼Â¹ÔÃæ¤Ë¥·¥°¥Ê¥ë¤ò¼õ¤±¤¿¡£

EINVAL

°ú¤­¿ô length ¤¬Éé¿ô¤Ç¤¢¤ë¤«¡¢ºÇÂç¥Õ¥¡¥¤¥ë¥µ¥¤¥º¤è¤êÂ礭¤¤¡£

EIO

inode ¤Î¹¹¿·»þ¤Ë I/O ¥¨¥é¡¼¤¬È¯À¸¤·¤¿¡£

EISDIR

»ØÄꤵ¤ì¤¿¥Õ¥¡¥¤¥ë¤Ï¥Ç¥£¥ì¥¯¥È¥ê¤Ç¤¢¤ë¡£

ELOOP

¥Ñ¥¹Ì¾¤ò²ò¼á¤¹¤ëºÝ¤Ë¥·¥ó¥Ü¥ê¥Ã¥¯¥ê¥ó¥¯¤¬Â¿¤¹¤®¤¿¡£

ENAMETOOLONG

¥Ñ¥¹Ì¾Ãæ¤Î¥Ç¥£¥ì¥¯¥È¥ê̾¤¬ 255 ʸ»ú¤ò±Û¤¨¤Æ¤¤¤ë¡¢¤â¤·¤¯¤Ï¥Ñ¥¹Ì¾Á´ÂΤ¬ 1023 ʸ»ú¤ò±Û¤¨¤Æ¤¤¤ë¡£

ENOENT

»ØÄꤵ¤ì¤¿Ì¾Á°¤Î¥Õ¥¡¥¤¥ë¤¬Â¸ºß¤·¤Ê¤¤¡£

ENOTDIR

¥Ñ¥¹Ì¾Ãæ¤Î¹àÌܤ˥ǥ£¥ì¥¯¥È¥ê¤Ç¤Ï¤Ê¤¤¤â¤Î¤¬Æþ¤Ã¤Æ¤¤¤ë¡£

EPERM

²¼Áؤˤ¢¤ë¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Ç¤Ï¡¢¸½ºß¤Î¥Õ¥¡¥¤¥ëŤò±Û¤¨¤Æ ¥Õ¥¡¥¤¥ë¤ò¿­Ä¹¤¹¤ë¤³¤È¤¬¤Ç¤­¤Ê¤¤¡£

EROFS

»ØÄꤵ¤ì¤¿¥Õ¥¡¥¤¥ë¤ÏÆɤ߽Ф·ÀìÍѤΥե¡¥¤¥ë¥·¥¹¥Æ¥àÃæ¤Ë¤¢¤ë¡£

ETXTBSY

»ØÄꤵ¤ì¤¿¥Õ¥¡¥¤¥ë¤Ï¼Â¹Ô¤µ¤ì¤Æ¤¤¤ë¥Õ¥¡¥¤¥ë¤Ç¤¢¤ë¡£

ftruncate() ¤Ë¤âƱÍͤΥ¨¥é¡¼¤¬Å¬ÍѤµ¤ì¤ë¡£ ⤷¡¢ path ¤Ë´Ø¤¹¤ë¥¨¥é¡¼¤Î¾ì¹ç¤ÏÂå¤ï¤ê¤Ë fd ¤Ë´Ø¤¹¤ë¥¨¥é¡¼¤È¤Ê¤ë¡£

EBADF

fd ¤¬Ìµ¸ú¤Ê¥Ç¥£¥¹¥¯¥ê¥×¥¿¡¼(descripter)¤Ç¤¢¤ë¡£

EBADF ¤Þ¤¿¤Ï EINVAL

fd ¤Ç»ØÄꤵ¤ì¤Æ¤¤¤ë¤â¤Î¤¬½ñ¤­¹þ¤ß¥â¡¼¥É¤Ç³«¤«¤ì¤Æ¤¤¤Ê¤¤¡£

EINVAL

fd ¤¬Ä̾ï¤Î¥Õ¥¡¥¤¥ë¤ò»²¾È¤·¤Æ¤¤¤Ê¤¤¡£

½àµò

4.4BSD, SVr4, POSIX.1-2001 (¤³¤ì¤é¤Î¥³¡¼¥ë¤Ï 4.2BSD ¤Ç½é¤á¤ÆÅо줷¤¿)¡£

Ãí°Õ

¾åµ­¤Îµ­½Ò¤Ï XSI ½àµò¤Î¥·¥¹¥Æ¥à¤Î¤â¤Î¤Ç¤¢¤ë¡£ XSI Èó½àµò¤Î¥·¥¹¥Æ¥à¤Î¾ì¹ç¡¢POSIX ɸ½à¤Ï ftruncate() ¤ËÂФ·¤Æ length ¤¬¥Õ¥¡¥¤¥ë¤ÎŤµ¤è¤êŤ«¤Ã¤¿¾ì¹ç¡¢ ¥¨¥é¡¼¤òÊÖ¤¹¤«¥Õ¥¡¥¤¥ë¤ò¿­Ä¥¤¹¤ë¤«¤ÎÆó¤Ä¤ÎÆ°ºî¤òµöÍƤ·¤Æ¤¤¤ë¡£ truncate() ¤ËÂФ·¤Æ¤ÏÁ´¤¯µ¬Äꤵ¤ì¤Æ¤¤¤Ê¤¤¡£ ¤Û¤È¤ó¤É¤Î Unix ¼ÂÁõ¤ÈƱÍÍ¡¢Linux ¤Ï¥Í¥¤¥Æ¥£¥Ö (Linux ͳÍè) ¤Î ¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Î°·¤¤¤Ç¤Ï XSI Í×µá»ÅÍͤˤ·¤¿¤¬¤Ã¤Æ¤¤¤ë¡£ ¤·¤«¤·¤Ê¤¬¤é¡¢¤¤¤¯¤Ä¤«¤ÎÈó¥Í¥¤¥Æ¥£¥Ö¤Î¥Õ¥¡¥¤¥ë¥·¥¹¥Æ¥à¤Ç¤Ï¡¢ truncate() ¤ä ftruncate() ¤ò»È¤Ã¤Æ¸½ºß¤Î¥Õ¥¡¥¤¥ëŤò±Û¤¨¤Æ¥Õ¥¡¥¤¥ë¤ò¿­Ä¹¤¹¤ë¤³¤È¤¬¤Ç¤­¤Ê¤¤¡£ Linux ¤Ç¤Îͭ̾¤ÊÎã¤È¤·¤Æ¤Ï VFAT ¤¬¤¢¤ë¡£

´ØÏ¢¹àÌÜ

open(2), stat(2), path_resolution(7)