1992.5.26


SUBJECT: Sticky Bit¿¡ ´ëÇØ 

DESCRIPTION:
    1. Sticky bitÀÇ ÀǹÌ
       * ÀüÅëÀû ÀÇ¹Ì : ¼öÇà ¼Óµµ Áõ°¡
       * »õ·Î¿î ÀÇ¹Ì : ±âÁ¸ Àǹ̿¡´Ù ÀÏÁ¤ Á¤µµÀÇ security ÀÇ ÀÇ¹Ì ºÎ¿©
                       Áï owner³ª super user¸¸ delete °¡´É.
    2. Execution TripletÀÇ  setting À§Ä¡
        - setuid - setgid - stickybit
    3. Program Execution TripletÀÇ  display À§Ä¡
       * sticky bit´Â othersÀÇ execution mode¿¡ setting
       * setuid bit´Â ownerÀÇ execution mode¿¡ setting
       * setgid bit´Â groupÀÇ execution mode¿¡ setting
    4. sticky bit¸¦ Æ÷ÇÔÇÏ¿© setuid,setgidµîÀº 
       ½ÇÇà(execution) fileµé¿¡ settingÇÏ´Â °ÍÀÓÀ» ÀØÁö ¸¶½Ã±æ.
    5. ½ÇÇà file ÀÏÁö¶óµµ execution mode°¡ offµÈ  °÷¿¡ execution triplet Çϳª°¡
       settingµÇ¸é execution triplet mode°¡ ´ë¹®ÀÚ·Î µÈ´Ù.  
       ¿¹¸¦ µç´Ù. 
            # ls -l shtest
            -rwxr-xr-x  1 woo            44 Mar 20 10:14 shtest
            # chmod 1777 shtest
            # ls -l shtest
            -rwxrwxrwt  1 woo            44 Mar 20 10:14 shtest
            # chmod 0744 shtest
            # ls -l shtest
            -rwxr--r--  1 woo            44 Mar 20 10:14 shtest
            # chmod 1744 shtest
            # ls -l shtest
            -rwxr--r-T  1 woo            44 Mar 20 10:14 shtest
    6. user°¡ ÀڽŠ¼ÒÀ¯ÀÇ fileÀÌ¶óµµ sticky bit »ý¼ºÀº ¾ÈµÊ(Àý´ë,»ó´ë mode ¸ðµÎ).
       ±×·¯³ª root¿¡¼­ ÀÛ¾÷ÇÏ¸é °¡´É.  super user°¡ sticky bit »ý¼º ÈÄ ±× fileÀÌ
       user ÀÚ½ÅÀÇ ¼ÒÀ¯¶ó¸é sticky mode¸¦ deleteÇÒ ¼ö´Â ÀÖ´Ù.

   Revision History
   Created        on May 26 ,1992
   Updated        on May 26 ,1992