quite a few programs

Author: Ravi kumar

DisectingString/.vscode/.BROWSE.VC.DB

@@ -0,0 +1,41 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "C++ Launch",
+            "type": "cppdbg",
+            "request": "launch",
+            "program": "enter program name, for example ${workspaceRoot}/a.out",
+            "args": [],
+            "stopAtEntry": false,
+            "cwd": "${workspaceRoot}",
+            "environment": [],
+            "externalConsole": true,
+            "linux": {
+                "MIMode": "gdb"
+            },
+            "osx": {
+                "MIMode": "lldb"
+            },
+            "windows": {
+                "MIMode": "gdb"
+            }
+        },
+        {
+            "name": "C++ Attach",
+            "type": "cppdbg",
+            "request": "attach",
+            "program": "enter program name, for example ${workspaceRoot}/a.out",
+            "processId": "${command.pickProcess}",
+            "linux": {
+                "MIMode": "gdb"
+            },
+            "osx": {
+                "MIMode": "lldb"
+            },
+            "windows": {
+                "MIMode": "gdb"
+            }
+        }
+    ]
+}

DisectingString/.vscode/launch.json

@@ -0,0 +1,76 @@
+#include<stdio.h>
+#include<string.h>
+
+int dealWithSpace(int );
+int dealWithQuotes(int );
+//void dealWithLastWord(void);
+
+char inputString[20];
+int flag1=0, quoteFlag1 = 0;
+ 
+int main(void){
+ int length;
+int i=0, j=0;
+
+printf("Enter string: ");
+fgets(inputString, 20, stdin);
+
+
+
+// printf("the inputString is: %s", inputString);
+
+length = (int)strlen(inputString);
+// printf("%d", length);
+
+while(i < length-2) {
+	if( (inputString[i] == (char)32 || inputString[i] == (char)'\0') && ( inputString[i+1] != (char)34) )
+		i = dealWithSpace(i);
+	else if(inputString[i] == (char)34)
+		i = dealWithQuotes(i);
+	i++;
+	}
+//	dealWithLastWord(); 
+	return 0;
+}	
+
+int dealWithSpace(int index) 
+{
+	char tempArray[10];
+	int  k = 0, i = 0;
+	
+	flag1 = index + 1;
+	index++;
+	while(inputString[index] != (char)32 || inputString[index] != '\0')
+		index++;
+	for(i = flag1, k = 0; i <= index; i++, k++)
+		tempArray[k] = inputString[i];
+	
+	printf("Token: %s", tempArray);
+	index += 1;
+	return index;
+}
+
+int dealWithQuotes(int index)
+{
+	char tempArray[10];
+	int i = 0, k = 0;
+	
+	quoteFlag1 = index + 1;
+	while(inputString[index] != (char)34 || inputString[index] != '\0')
+		index++;
+	for(i = flag1, k = 0; i <= index; i++, k++)
+		tempArray[k] = inputString[i];
+	printf("Token: %s", tempArray);
+	index += 2;
+	return index;
+
+}
+
+// void dealWithLastWord(){
+// 	int i;
+// 	printf("Token: ");
+// 	for(i = flag1; i < strlen(inputString); i++)
+// 		printf("%c", inputString[i]);
+// 	printf("\n");
+// }
+

DisectingString/DisectingString.c

@@ -87,6 +87,7 @@ FILE *fp = fopen("vault.txt", "rb");
 	while(fread(&search, sizeof(struct record), 1, fp) != 0){ 
 	if( strcmp(tempUserName, search.userName) == 0 && strcmp(tempPassword, search.password) == 0 ){			           				    			 printf("%s", spaces);
 					printf("Acccess Granted!\n");
+					system("./mainprogram");
 					return;
 				}
 

DisectingString/a.out

@@ -0,0 +1,160 @@
+#include <unistd.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <stdlib.h>  
+#include <sys/wait.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <iostream>
+using namespace std;
+
+
+void producerHandler (int sig);  
+void consumerHandler (int sig);  
+
+
+const int BUFFER_SIZE = 5;  
+struct SharedMemory          
+{
+	int numItems;            
+	int in, out;              
+	int buffer[BUFFER_SIZE];  
+};
+
+int shmid;                 
+SharedMemory *shmptr;      
+pid_t child_pid;           
+
+int main()
+{
+	
+	shmid = shmget(IPC_PRIVATE, sizeof(struct SharedMemory), 0666|IPC_CREAT);   
+	if (shmid == -1) {
+		cerr << "shmget failed\n";
+		exit(EXIT_FAILURE);
+	}
+
+	
+	child_pid = fork();
+	if (child_pid < 0) { 
+		cerr << "Fork Failed\n";
+		exit(-1);
+	}
+
+	if (child_pid == 0) 
+	{ 
+		signal (SIGINT, consumerHandler);  
+		cout << "I am the consumer\n"
+			<< "Consumer will sleep for a bit to make sure that producer "
+			<< "initializes shared memory" << endl;
+		sleep(1);
+
+		
+		cout << "Consumer: attaching shared memory\n";
+		shmptr = (SharedMemory*)shmat(shmid, NULL, 0);
+		if (shmptr == (SharedMemory *)-1) {
+			cerr << "shmat failed\n";
+			exit(EXIT_FAILURE);
+		}
+		cout << "Consumer: memory attached\n";
+
+		
+		while (true)
+		{
+			cout << "Consumer attempting to read\n";
+			
+			while (shmptr->numItems == 0)
+				;  
+			
+			shmptr->numItems--; 
+
+			int nextConsumed = shmptr->buffer[shmptr->out];
+
+			cout << "Consumer read: " << nextConsumed	<< " at index " << shmptr->out << endl;
+
+			shmptr->out = (shmptr->out + 1) % BUFFER_SIZE;
+
+			sleep(rand()%3);  // 0-3 seconds
+
+		}  
+
+	}  
+	else 
+	{ 
+		signal (SIGINT, producerHandler);  
+		cout << "I am the producer\n";
+
+		
+		cout << "Producer: attaching shared memory\n";
+		shmptr = (SharedMemory *)shmat(shmid, (void *)0,0);
+		if (shmptr == (SharedMemory *)-1) {
+			cerr << "shmat failed\n";
+			exit(EXIT_FAILURE);
+		}
+		cout << "Producer: memory attached\n";
+
+		
+		cout << "Producer: initializing shared memory\n";
+		shmptr->in = 0;
+		shmptr->out = 0;
+		shmptr->numItems = 0;
+		cout << "Producer: shared memory initialized\n";
+
+		
+		while (true)
+		{
+			cout << "Producer attempting write\n";
+
+			int nextProduced = rand()%10000; 
+
+			while (shmptr->numItems == BUFFER_SIZE)
+				;  // do nothing
+
+			shmptr->buffer[shmptr->in] = nextProduced;
+
+			cout << "Producer wrote: " << nextProduced 	<< " at index " << shmptr->in << endl;
+
+			shmptr->in = (shmptr->in + 1) % BUFFER_SIZE;
+
+			shmptr->numItems++;  // CRITICAL section
+
+			sleep(rand()%3);  // 0-3 seconds
+
+		} 
+	}  
+}  
+
+
+void consumerHandler (int sig)
+{
+	
+	cout << "Consumer detaching shared memory\n";
+	if (shmdt(shmptr) == -1) {
+		cerr << "shmdt failed\n";
+		exit(EXIT_FAILURE);
+	}
+	exit(EXIT_SUCCESS);
+}  
+
+
+void producerHandler (int sig)
+{
+	
+	cout << "Producer killing consumer\n";
+	kill (child_pid, SIGINT);
+	wait (NULL);
+
+	cout << "Producer detaching and removing shared memory\n";
+	
+	if (shmdt(shmptr) == -1) {
+		cerr << "shmdt failed\n";
+		exit(EXIT_FAILURE);
+	}
+	
+	if (shmctl(shmid, IPC_RMID, 0) == -1) {
+		cerr << "shmctl(IPC_RMID) failed\n";
+		exit(EXIT_FAILURE);
+	}
+	exit(EXIT_SUCCESS);
+}  
+