리눅스 시그널 Linux Signal

https://man7.org/linux/man-pages/man7/signal.7.html

 

 

리눅스에서 프로세스를 강제로 종료할 때 왜 kill -9를 사용할까?!

"9"의 의미는 리눅스 시그널인 SIGKILL이고 프로그램 내에서 이 시그널을 받았을 때 종료하도록 되어 있기 때문이다.

 

다른 시그널에 대해서도 각각 핸들러를 구현할 수 있다. 

 

 

시그널 종류와 번호, POSIX 표준 정리 표 (사용해 보거나 핸들러를 구현해 본 시그널은 굵은 표시)

Signal	x86/ARM most others	Alpha/ SPARC	MIPS	PARISC	Notes	Standard	Action	Comment
SIGHUP	1	1	1	1		P1990	Term	Hangup detected on controlling terminal or death of controlling process
SIGINT	2	2	2	2		P1990	Term	Interrupt from keyboard
SIGQUIT	3	3	3	3		P1990	Core	Quit from keyboard
SIGILL	4	4	4	4		P1990	Core	Illegal Instruction
SIGTRAP	5	5	5	5		P2001	Core	Trace/breakpoint trap
SIGABRT	6	6	6	6		#N/A	#N/A	#N/A
SIGIOT	6	6	6	6		-	Core	IOT trap. A synonym for SIGABRT
SIGBUS	7	10	10	10		#N/A	#N/A	#N/A
SIGEMT	-	7	7	-		#N/A	#N/A	#N/A
SIGFPE	8	8	8	8		#N/A	#N/A	#N/A
SIGKILL	9	9	9	9		P1990	Term	Kill signal
SIGUSR1	10	30	16	16		P1990	Term	User-defined signal 1
SIGSEGV	11	11	11	11		P1990	Core	Invalid memory reference
SIGUSR2	12	31	17	17		P1990	Term	User-defined signal 2
SIGPIPE	13	13	13	13		P1990	Term	Broken pipe: write to pipe with no readers; see pipe(7)
SIGALRM	14	14	14	14		#N/A	#N/A	#N/A
SIGTERM	15	15	15	15		P1990	Term	Termination signal
SIGSTKFLT	16	-	-	7		-	Term	Stack fault on coprocessor (unused)
SIGCHLD	17	20	18	18		#N/A	#N/A	#N/A
SIGCLD	-	-	18	-		#N/A	#N/A	#N/A
SIGCONT	18	19	25	26		#N/A	#N/A	#N/A
SIGSTOP	19	17	23	24		P1990	Stop	Stop process
SIGTSTP	20	18	24	25		P1990	Stop	Stop typed at terminal
SIGTTIN	21	21	26	27		P1990	Stop	Terminal input for background process
SIGTTOU	22	22	27	28		P1990	Stop	Terminal output for background process
SIGURG	23	16	21	29		P2001	Ign	Urgent condition on socket (4.2BSD)
SIGXCPU	24	24	30	12		P2001	Core	CPU time limit exceeded (4.2BSD); see setrlimit(2)
SIGXFSZ	25	25	31	30		P2001	Core	File size limit exceeded (4.2BSD); see setrlimit(2)
SIGVTALRM	26	26	28	20		P2001	Term	Virtual alarm clock (4.2BSD)
SIGPROF	27	27	29	21		#N/A	#N/A	#N/A
SIGWINCH	28	28	20	23		-	Ign	Window resize signal (4.3BSD, Sun)
SIGIO	29	23	22	22		#N/A	#N/A	#N/A
SIGPOLL					Same as SIGIO	#N/A	#N/A	#N/A
SIGPWR	30	29/-	19	19		#N/A	#N/A	#N/A
SIGINFO	-	29/-	-	-		#N/A	#N/A	#N/A
SIGLOST	-	-/29	-	-		#N/A	#N/A	#N/A
SIGSYS	31	12	12	31		#N/A	#N/A	#N/A
SIGUNUSED	31	-	-	31		#N/A	#N/A	#N/A