ans  =
 
    1.  
 
-->exec('Example2.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   
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 Code Author                          :                                                     Pranav Bhat T   
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 Chapter Number                    :                                                                            23   
 
 Chapter Title                         :                              Systems programming II- Files   
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Example 2    :               Show the method of showing PID,PPID in both parent and child process 
 
 ****************************************************************   
 
 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 fork.c      # to open the file emp.lst /* Program: fork.c -- A simple fork Shows PID,PPID in both parent and child*/

#include <stdio.h>
#include <sys/types.h>

int main(void) {
    pid_t pid;
    
    printf("Before forking\n");
    pid = fork();        /* Replicates current processes */
    
    if(pid >0) {         /* In the parent process; make sure */
    sleep(1);            /* That the parent does not die before child */
    printf("PARENT -- PID: %d PPID %d, CHILD PID: %d\n",getpid(),getppid(),pid);}
    
    else if (pid == 0)    /* In the child process */
         printf("CHILD -- PID: %d PPID: %d\n",getpid(),getppid());
    else {                 /* pid must be -1 here */
         printf("Fork error\n");
         exit(1);}
    printf("Both process continue from here\n");  /* In both processes */
    exit(0);
}
 $ cc fork.c $ a.out Before forking
CHILD -- PID: 1556 PPID: 1555
Both processes continue from here         # This statement runs in child
PARENT -- PID: 1555 PPID: 1450,CHILD PID: 1556
Both processes continue from here          ...as well as in parent
 


$ 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)