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ans =
1.
-->exec('Example5.sci')
-->clear
-->flag=1
flag =
1.
-->mode(-1)
Current date is 23-Jun-2013
Welcome to the Textbook Companionship Project 2013
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Book Title : UNIX CONCEPTS AND APPLICATIONS
Book Edition : 4
Book Author : Sumitabha Das
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Code Author : Pranav Bhat T
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Chapter Number : 24
Chapter Title : Systems programming II- Files
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Example 5 : Show the effect of creating an orphan by letting child sleep for 2 minutes where parent dies immediately
****************************************************************
Answer :
INSTRUCTIONS :
1.These programs are part of systems programming PURELY in Unix and the commands have NO EQUIVALENT IN SCILAB
2.However the .c files which are displayed here are also made into a seperate file.If you are a unix user then try compiling and
running the programme with gcc or cc compiler
3.The outputs displayed here are just MOCK OUTPUTS which are DISPLAYED IN THE TEXTBOOK
4.The inconvenience is regretted.
.............Press [ENTER] to continue..... UNIX SHELL SIMULATOR(DEMO VERSION WITH PRELOADED COMMANDS)
$ cat orphan.c # to open the file emp.lst /* Program: orphan.c -- Creates an orphan by letting child sleep for 2 minutes.
Parent doesn't call wait and dies immediately */
#include <stdio.h>
int main(void) {
int pid;
if ((pid = fork()) > 0) /* Parent */
exit(10); /* Parent exits without calling wait */
else if (pid == 0) { /* Child */
sleep(2); /* Lets parent die in this time frame */
printf("CHILD: Adopted by init now, PPID: %d\n",getppid());
exit(0);
}
}
$ cc orphan.c $ a.out ....no response for 2 seconds... CHILD: Adopted by init now, PPID: 1 $ echo $? 10
$ exit #To exit the current simulation terminal and return to Scilab console
........# (hit [ENTER] for result)
BACK TO SCILAB CONSOLE...
Loading initial environment
-->diary(0)
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