¾Õ Àý¿¡¼ ¼³¸íÇÑ ¹Ù¿Í °°ÀÌ init ÇÁ·Î¼¼½º°¡ Àڽſ¡°Ô ÇÒ´çµÈ ÃʱâÈ °úÁ¤À» ¸ðµÎ ³¡¸¶Ä¡°í ³ª¸é, inittab ÆÄÀÏÀÇ ¸Ç ³¡ºÎºÐ¿¡ ¸í½ÃµÈ °Íó·³ mingetty ȤÀº getty ÇÁ·Î¼¼½º¸¦ ½ÇÇà½Ãŵ´Ï´Ù. ½ÇÇà½ÃŰ´Â ¹æ¹ýÀº ÃÖÃÊ¿¡ pid 0 ÀÇ ÇÁ·Î¼¼½º¿¡ ÀÇÇØ ½ÇÇàµÈ "¿Õ"(?) init °¡ fork() ½Ã½ºÅÛ ÄÝÀ» Çѹø ¼öÇàÇϰí, ±×¿¡ ÀÇÇØ »ý¼ºµÈ ÀÚ½Ä init °¡ exec() ½Ã½ºÅÛ ÄÝÀ» ÀÌ¿ëÇØ¼ mingetty µîÀÇ ÇÁ·Î¼¼½º¸¦ ¼öÇàÇÏ°Ô µË´Ï´Ù. ±×¸®°í ³ª¼, mingetty ÇÁ·Î¼¼½º´Â ´Ù½Ã exec() ¸¦ È£ÃâÇÏ¿© login ÇÁ·Î¼¼½º¸¦ ¼öÇàÇϰí, login ÇÁ·Î¼¼½º´Â »ç¿ëÀÚÀÇ userid ¿Í passwd ¸¦ ÀԷ¹޾Ƽ »ç¿ëÀÚ ÀÎÁõ°úÁ¤À» °ÅĨ´Ï´Ù. ¸¸¾à, ½ÂÀÎµÈ »ç¿ëÀÚ¶ó¸é, /etc/passwd ÆÄÀÏ¿¡ ¸í½ÃµÈ »ç¿ëÀÚ¿¡ ÇØ´çÇÏ´Â ½©À» ¶ç¿ì°Ô µË´Ï´Ù. ½©À» ¶ç¿ì´Â °Í ¶ÇÇÑ exec() ½Ã½ºÅÛ ÄÝÀ» ÀÌ¿ëÇØ¼ ÀÔ´Ï´Ù. ±×·¯¸é, »ç¿ëÀÚ´Â ÀÚ½ÅÀÇ ½© (ÁÖ·Î bash) ·Î ÀÛ¾÷À» Çϰí, ½©¿¡¼ ÀÔ·ÂÇÏ´Â ¸í·É¾îµéÀº ¸ÕÀú ½©ÀÌ fork() ¸¦ ÇÑ ÈÄ ½©ÀÇ ÀÚ½ÄÇÁ·Î¼¼½º°¡ exec() ¸¦ ÇÏ¿© ½ÇÇàµÇ°í, Á¾·áÇÏ´Â °ÍÀÔ´Ï´Ù. ÀÌ °úÁ¤À» °£´ÜÇÏ°Ô ±×¸²À¸·Î ±×¸®¸é ´ÙÀ½°ú °°½À´Ï´Ù.
+-------------+ | "¿Õ" init | | (pid 1) | +------+------+ | <-------------------------------------+ | fork() | respawn \|/ | +------+------+ | | "ÀÚ½Ä" init | | | (pid 266) | | +------+------+ | | | | exec() | \|/ | +------+------+ | | mingetty | | | (pid 266) | | +------+------+ | | | | exec() | \|/ | +------+------+ | | login | | | (pid 266) | | +------+------+ | | | | exec() | \|/ | +------+------+ | | bash +---------------------------- ½© Á¾·á | (pid 266) | ·Î±×¾Æ¿ô +------+------+ | ¸í·É¾î ¼öÇà | fork() \|/ +------+------+ | bash | | (pid5909) | +------+------+ | | exec() \|/ +------+------+ |´Ù¸¥ ÇÁ·Î¼¼½º| | (pid5909) | +------+------+ |