- Implemented step 1-6 of OS assignment 3.

2010-10-19-uva/2010-10-19-uva.tex

@@ -324,20 +324,20 @@
 }
 
 \section{Toekomst}
-	
+
 \frame
 {
 	\frametitle{Toekomstbeeld}
 	
 	\begin{itemize}
-	\item Verschillende vakken
-	\item Nakijkmodule
-	\item Automatisch nakijken
+		\item Verschillende vakken
+		\item Nakijkmodule
+		\item Automatisch nakijken
 	\begin{itemize}
 		\item Mini unit tests
 		\item Fuzzy matching van code
 	\end{itemize}
-	\item Met meerdere gebruikers aan dezelfde code werken
+		\item Met meerdere gebruikers aan dezelfde code werken
 	\end{itemize}
 }
 

os/ass3/fishbones.c

@@ -2,11 +2,14 @@
 #include <stdlib.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <errno.h>
+#include <signal.h>
 
 static void gup(FILE * log1, FILE * log2, int pipe_id[2], int myNumber)
 {
 	FILE * log3;
 	char c;
+	int antidote = 0;
 	/* Put any required declarations and initialisations here */
 	
 	close(pipe_id[1]);
@@ -31,12 +34,53 @@ static void gup(FILE * log1, FILE * log2, int pipe_id[2], int myNumber)
 		   an end-of-file (read returns zero), end your program
 		   with an exit(1) */
 		
+		if( read(pipe_id[0], &c, 1) <= 0 )
+		{
+			fprintf(log1, "Child %d exited with error \n", myNumber);
+			fprintf(log2, "Child %d exited with error \n", myNumber);
+			fprintf(log3, "Child %d exited with error \n", myNumber);
+			fclose(log1);
+			fclose(log2);
+			fclose(log3);
+			exit(1);
+		}
+		
 		fprintf(log1, "Child %d read character '%x'\n", myNumber, c);
 		fprintf(log2, "Child %d read character '%x'\n", myNumber, c);
 		fprintf(log3, "Child %d read character '%x'\n", myNumber, c);
 
-		/* process the character here */
-	} while ( 0);/* Put a suitable condition here * );*/
+		switch( c )
+		{
+			case 'P':
+				fprintf(log1, "Child %d eats poison...", myNumber);
+				fprintf(log2, "Child %d eats poison...", myNumber);
+				fprintf(log3, "Child %d eats poison...", myNumber);
+				
+				if( !antidote )
+				{
+					fprintf(log1, "no antidote, child will exit\n");
+					fprintf(log2, "no antidote, child will exit\n");
+					fprintf(log3, "no antidote, child will exit\n");
+					break;
+				}
+				else
+				{
+					antidote--;
+					fprintf(log1, "antidote used \n");
+					fprintf(log2, "antidote used \n");
+					fprintf(log3, "antidote used \n");
+				}
+				break;
+			case 'A':
+				antidote++;
+				fprintf(log1, "Child %d finds antidote (now has %d andidote)\n",
+				        myNumber, antidote);
+				fprintf(log2, "Child %d finds antidote (now has %d andidote)\n",
+				        myNumber, antidote);
+				fprintf(log3, "Child %d finds antidote (now has %d andidote)\n",
+				        myNumber, antidote);
+		}
+	} while( c != '\0' );
 	
 	fprintf(log1, "Child %d normal exit \n", myNumber);
 	fprintf(log2, "Child %d normal exit \n", myNumber);
@@ -54,19 +98,25 @@ main(int argc, char * argv[])
 {
 	FILE * log1;
 	FILE * log2;
-	char inString[STRING_LENGTH];
-	int kiddoCount = 0, pipe_id[2], i = 1;
-	printf("argc: %d\n",argc);
+	char c;
+	int kiddoCount = 0, pipe_id[2];//, i = 1;
+	printf("argc: %d\n", argc);
 	log1 = fopen("child.log1", "wt+");
 	log2 = fopen("child.log2", "wt+");
 	setvbuf(log2, NULL, _IONBF, BUFSIZ);
 	/* So log1 is buffered; log2 is not buffered, which means that output
 	   to log2 is written immediately. */
 	
+	if( pipe(pipe_id) )
+	{
+		fprintf(stderr, "Error %d occured while createing the pipe \n", errno);
+		exit(1);
+	}
+	
 	/* create the pipe somewhere around here (why?).
 	   remember to test for success!! */
 	
-	while( fgets(inString, STRING_LENGTH, stdin) )
+	while( (c = getchar()) )
 	{
 		/* You can now choose to use only the first character in the
 		   string (inString[0]), or the entire string (how would you test
@@ -74,33 +124,60 @@ main(int argc, char * argv[])
 		   Anyway, read a character, echo it to both log files 
 		   and write it into the pipe (unless you have to call fork)
 		   */
-	
-		if( /* suitable condition */ )
+		
+		/* Ignore newlines and spaces */
+		if( c == '\n' || (int)c == 32 )
 		{
-			/* write to pipe */
+			continue;
+		}
+		
+		fprintf(log1, "Character %x read \n", c);
+		fprintf(log2, "Character %x read \n", c);
+		printf("Character '%c' read \n", c);
+		
+		if( c == 'q' )
+		{
+			break;
+		}
+		else if( c == 'P' )
+		{
+			wait();
+		}
+		else if( c != 'f' )
+		{
+			if( write(pipe_id[1], &c, 1) != 1 )
+			{
+				perror("Cannot write to pipe \n");
+				exit(1);
+			}
 		}
 		else
 		{
 			pid_t child_id;
 			
-			kiddoCount ++;
+			kiddoCount++;
 			
 			/* When you fork, be sure to print the process id of the child
 			   (if the fork succeeds) and an error message otherwise */
 			
-			if( child_id = fork() )
-			{
-				/* What code should go here ? */
-			}
-			else
+			switch( (child_id = fork()) )
 			{
-				/* What goes here ? */
+				case -1:
+					perror("Child could not be created \n");
+					exit(1);
+				case 0:
+					gup(log1, log2, pipe_id, child_id);
+					break;
+				default:
+					puts("Parent process continuing...");
 			}
 		}
 	}
 	
-	/* normal end of program */
-	/* close all open log files */
+	fprintf(log1, "Program exited normally \n");
+	fprintf(log2, "Program exited normally \n");
+	fclose(log1);
+	fclose(log2);
 	
 	return 0;
 }

paper/paper.tex

-\documentclass[twocolumn]{article}
+TT\documentclass[twocolumn]{article}
 \usepackage{url}
 
 \title{Web-based digital examination for specific learning areas}