initial commit / add all books

1 files changed, 109 insertions, 0 deletions

diff --git a/1088/CH24/EX24.16/Example16.sce b/1088/CH24/EX24.16/Example16.sce
new file mode 100755
index 000000000..56ba0d218
--- /dev/null
+++ b/1088/CH24/EX24.16/Example16.sce
@@ -0,0 +1,109 @@
+clear
+flag=1
+mode(-1)
+clc
+//Program for example 1 chapter 1
+printf("Current date is %s \n \nWelcome to the Textbook Companionship Project 2013 \n",date())
+printf("+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n")
+disp("Book Title                             :       UNIX CONCEPTS AND APPLICATIONS ")
+disp("Book Edition                         :                                                                           4")
+disp("Book Author                          :                                                    Sumitabha Das")
+printf("+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n")
+disp("Code Author                          :                                                     Pranav Bhat T")
+printf("+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n")
+disp("Chapter Number                    :                                                                            24")
+disp("Chapter Title                         :                              Systems programming II- Files")
+printf("+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n"
+printf("Example 16    :       Show the method of using fork and exec to run a user-defined\n program and kill it in 5 seconds if not completed \n")
+disp("****************************************************************")
+disp("Answer    :   ")
+disp("INSTRUCTIONS   : ")
+halt(' ')
+disp("1.These programs are part of systems programming PURELY in Unix and the commands have NO EQUIVALENT IN SCILAB")
+halt(' ')
+disp("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")
+halt(' ')
+disp("3.The outputs displayed here are just MOCK OUTPUTS which are DISPLAYED IN THE TEXTBOOK")
+halt(' ')
+disp("4.The inconvenience is regretted.")
+halt('.............Press [ENTER] to continue.....')
+halt("")
+clc
+printf("\tUNIX SHELL SIMULATOR(DEMO VERSION WITH PRELOADED COMMANDS)\n\n\n")
+
+
+i=0
+i=i+1;f(i)='/* Program: killprocess.c -- Uses fork and exec to run a user-defined program and kills it if it doesnt complete in 5 seconds */'
+i=i+1;f(i)='#include <stdio.h>'
+i=i+1;f(i)='#include <sys/types.h>'
+i=i+1;f(i)='#include <sys/wait.h>'
+i=i+1;f(i)='#include <signal.h>'
+i=i+1;f(i)=''
+i=i+1;f(i)='pid_t pid;'
+i=i+1;f(i)='int main(int argc, char **argv) {'
+i=i+1;f(i)='    int i,status;'
+i=i+1;f(i)='    void death_handler(int signo);   /* A common signal handler this time */'
+i=i+1;f(i)='    '
+i=i+1;f(i)='    signal(SIGCHLD, death_handler);  /* death_handler is invoked when a */'
+i=i+1;f(i)='    signal(SIGALRM, death_handler);  /* child dies or an alarm is recieved */'
+i=i+1;f(i)='    '
+i=i+1;f(i)='    switch (pid = fork()) {'
+i=i+1;f(i)='           case -1: printf('+ascii(34)+'Fork error\n'+ascii(34)+');'
+i=i+1;f(i)='           case 0: execvp(argv[1],&argv[1]);   /* Execute command */'
+i=i+1;f(i)='                   perror('+ascii(34)+'exec'+ascii(34)+');'
+i=i+1;f(i)='                   break;'
+i=i+1;f(i)='           default: alarm(5);      /* Will send SIGALRM after 5 seconds */'
+i=i+1;f(i)='                   pause();        /* Will return when SIGCHILD signal is received */'
+i=i+1;f(i)='                   printf('+ascii(34)+'Parent dies\n'+ascii(34)+');'
+i=i+1;f(i)='                   }'
+i=i+1;f(i)='           exit(0);'
+i=i+1;f(i)='           }'
+i=i+1;f(i)='    '
+i=i+1;f(i)='    void death_handler(int signo) {      /* This common handler pics up the */'
+i=i+1;f(i)='          int status;                    /* exit status for normal termination */'
+i=i+1;f(i)='          signal(signo, death_handler);   /* but sends the SIGTERM signal if */'
+i=i+1;f(i)='          switch(signo) {                   /* command doesnt complete in 5 seconds */'
+i=i+1;f(i)='              case SIGCHLD: waitpid(-1, &status, 0); /* Same as wait(&status); */'
+i=i+1;f(i)='              printf('+ascii(34)+'Child dies; exit status: %d\n'+ascii(34)+',WEXITSTATUS(status));'
+i=i+1;f(i)='              break;'
+i=i+1;f(i)='          case SIGALRM: if (kill(pid, SIGTERM) == 0)'
+i=i+1;f(i)='                        fprintf(stderr, '+ascii(34)+'5 seconds over,child killed\n'+ascii(34)+');'
+i=i+1;f(i)='                        }'
+i=i+1;f(i)='}'
+n=i
+    
+
+printf("\n\n$ cat killprocess.c      # to open the file emp.lst")
+halt(' ')
+u=mopen('killprocess.c','wt')
+for i=1:n
+    mfprintf(u,"%s\n",f(i))
+    printf("%s\n",f(i))
+end
+mclose(u)
+halt('')
+clc
+
+halt(' ')
+ printf("$ cc killprocess.c")
+ halt(' ')
+ printf("$ a.out  date")
+ halt(' ')
+ printf("Sat Jun 20  22:29:27  IST 2013\nChild dies: exit status: 0\nParent dies")
+halt(' ')
+printf("\n")
+printf("$ a.out find /home -name a.out -print") 
+halt(' ')
+printf("/home /sumit/personal/project8/a.out\n/home/sumit/personal/books_code/glass_ables/12/a.out\n/home/sumit/personal/books_code/stevens_c/ch08/a.out")
+printf("  ..after 5 second time interval ...")
+sleep(5000)
+printf("\n5 seconds over, child killed\nParent dies\n")
+halt(' ')
+printf("\n\n\n$ exit        #To exit the current simulation terminal and return to Scilab console\n\n")
+halt("........# (hit [ENTER] for result)")
+//clc()
+
+printf("\n\n\t\t\tBACK TO SCILAB CONSOLE...\nLoading initial environment')
+sleep(1000)
+
+