Week Fourteen Agenda
Announcements
Final Exam
True/False -100 questions (1 point per question)
Multiple Choice - 40 questions (2 points per
question)
Essay -10 questions (2 point per question)
Final Exam Total Points 200
Review multiple choice and essay type questions
on final exam
If there are problems associated with taking the
exam, call me at 614.519.5853 and be persistent.
Week Fourteen Agenda
Agenda
Week Fourteen April 8, 2013 Open Source
presenter(s) are:
Ford Cunningham
Week Fourteen Agenda
Final Exam Questions
When a child process ends, a SIGCHLD signal is sent to the
parent process from the kernel indicating their child exited
(True).
When a child process ends, the kernel sends a SIGCHLD
signal to the parent. If the parent responses immediately with
a wait () system call, all memory and resources allocated to
the process are de-allocated (True).
To remove a zombie process from a system, the kernel sends
a SIGHUB signal to the parent process (False).
The /etc/inittab file for RHEL 6.0 does not contains a list of
run levels that can be used during the boot process. (True)
Would the initdefault run level variable be found in the
/etc/inittab file for RHEL 6.0? (True)
Week Fourteen Agenda
Final Exam Questions
The wait action keyword is used when a specific run level
is entered for action. (True)
The respawn action keyword is used to re-start a process
whenever it has terminated. (True)
When the system run level is changed, any running
processes that are not specified for the new run level are
killed. The unwanted processes are first sent a SIGTERM
signal, then a SIGKILL signal. (True)
Week Fourteen Agenda
Linux Signals are:
Signal Name Number Description
SIGHUP 1 Hangup (POSIX)
SIGINT 2 Terminal interrupt (ANSI)
SIGQUIT 3 Terminal quit (POSIX)
SIGILL 4 Illegal instruction (ANSI)
SIGTRAP 5 Trace trap (POSIX)
SIGIOT 6 IOT Trap (4.2 BSD)
SIGBUS 7 BUS error (4.2 BSD)
SIGFPE 8 Floating point exception (ANSI)
SIGKILL 9 Kill(can't be caught or ignored) (POSIX)
SIGUSR1 10 User defined signal 1 (POSIX)
SIGSEGV 11 Invalid memory segment access (ANSI)
SIGUSR2 12 User defined signal 2 (POSIX)
Week Fourteen Agenda
Linux Signals are:
SIGPIPE 13 Write on a pipe with no reader, Broken pipe
(POSIX)
SIGALRM 14 Alarm clock (POSIX)
SIGTERM 15 Termination (ANSI)
SIGSTKFLT 16 Stack fault
SIGCHLD 17 Child process has stopped or exited, changed
(POSIX)
SIGCONT 18 Continue executing, if stopped (POSIX)
SIGSTOP 19 Stop executing(can't be caught or ignored)
(POSIX)
SIGTSTP 20 Terminal stop signal (POSIX)
SIGTTIN 21 Background process trying to read, from TTY
(POSIX)
Week Fourteen Agenda
Linux Signals are:
SIGTTOU 22 Background process trying to write, to TTY
(POSIX)
SIGURG 23 Urgent condition on socket (4.2 BSD)
SIGXCPU 24 CPU limit exceeded (4.2 BSD)
SIGXFSZ 25 File size limit exceeded (4.2 BSD)
SIGVTALRM 26 Virtual alarm clock (4.2 BSD)
SIGPROF 27 Profiling alarm clock (4.2 BSD)
SIGWINCH 28 Window size change (4.3 BSD, Sun)
SIGIO 29 I/O now possible (4.2 BSD)
SIGPWR 30 Power failure restart (System V)
Command to display signal value: kill –l SIGTERM
Week Fourteen Agenda
Questions and Issues
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