OPERATING SYSTEMS LABORATORY

Author: sauravhathi

Subjects/CSE325 - OPERATING SYSTEMS LABORATORY/CSE325 End Term Practice Question Paper.pdf

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+#include<unistd.h>
+#include<stdio.h>
+#include<stdlib.h>
+#include<fcntl.h>
+
+int main()
+{
+    int fd[2],n;
+    char buffer[100];
+    pid_t p;
+    pipe(fd);
+    p = fork();
+    if(p>0)
+    {
+        close(fd[1]);
+        n = read(fd[0], buffer, 100);
+        write(1, buffer, n);
+        
+    }
+    else
+    {
+        close(fd[0]);
+        printf("Passing values to Parent\n");
+        write(fd[1],"Hello\n",6);
+        wait();
+        
+    }
+}

Subjects/CSE325 - OPERATING SYSTEMS LABORATORY/End Term Practical Question Paper and Solution/1a

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+#include<stdio.h>
+#include<fcntl.h>
+#include<unistd.h>
+
+int main()
+{
+	int fd1,fd2,n1,n2;
+	char buff1[100], buff2[100];
+	n2 = read(0,buff2,100);
+	fd2 = open("file2.txt",O_CREAT|O_RDWR,0777);
+	write(fd2,buff2,n2);
+	
+	fd1 = open("file1.txt",O_CREAT|O_RDWR,0777);
+	int off = lseek(fd2,-5,SEEK_END);
+	read(fd2, buff1, 5);
+	write(fd1,buff1,5);
+	printf("Number of characters in file2 is : %d\n",n2);
+	
+}

Subjects/CSE325 - OPERATING SYSTEMS LABORATORY/End Term Practical Question Paper and Solution/1a.c

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+#include<stdio.h>
+#include<fcntl.h>
+#include<unistd.h>
+int main()
+{
+	char buff[100],buff2[100];
+
+	int fd = open("file2.txt",O_RDWR,0777);
+	int n = read(fd,buff,100);
+	
+	for(int i=n;i>=0;i--)
+	{
+		buff2[n-i] = buff[i];		
+	}
+	write(1,buff2,n+1);
+}

Subjects/CSE325 - OPERATING SYSTEMS LABORATORY/End Term Practical Question Paper and Solution/1b

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+#include <stdio.h>
+#include <pthread.h>
+#include <semaphore.h>
+void inc();
+void dec();
+int shared = 1;
+sem_t s;
+int main()
+{
+  sem_init(&s,0,1); //1st arg: address of semaphore var, 2nd arg: no. of process sharing, 3rd arg: initialisation
+  pthread_t thread1,thread2;
+  pthread_create(&thread1, NULL, inc, NULL);
+  pthread_create(&thread2, NULL, dec, NULL);
+  pthread_join(thread1,NULL);
+  pthread_join(thread2,NULL);
+}
+
+void inc()
+{
+  int x;
+  sem_wait(&s);
+  x=shared;
+  x++;
+  sleep(1);
+  shared = x;
+  sem_post(&s);
+  printf("%d\n",shared );
+}
+void dec()
+{
+  int x;
+  sem_wait(&s);
+  x=shared;
+  x--;
+  sleep(1);
+  shared = x;
+  sem_post(&s);
+  printf("%d\n",shared );
+}

Subjects/CSE325 - OPERATING SYSTEMS LABORATORY/End Term Practical Question Paper and Solution/1b.c

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+#include<pthread.h>
+#include<stdio.h>
+#include<unistd.h>
+#include<stdlib.h>
+int global[2];
+
+void *sum(void *args)
+{
+    int *args_array;
+    args_array = args;
+    int n1,n2,sum=0;
+    n1 = args_array[0];
+    n2 = args_array[1];
+    sum = n1+n2;
+    pthread_exit(sum);
+}
+
+void *sub(void *args)
+{
+    int *args_array;
+    args_array = args;
+    int n1,n2,sub=0;
+    n1 = args_array[0];
+    n2 = args_array[1];
+    sub = n1-n2;
+    pthread_exit(sub);
+}
+
+int main()
+{
+	pthread_t t1,t2;
+	printf("Enter Value of n1 : ");
+	scanf("%d",&global[0]);
+	printf("\nEnter Value of n2 : ");
+	scanf("%d",&global[1]);
+	void *result1, *result2;
+	
+	pthread_create(&t1,NULL,sum,global);
+	pthread_create(&t2,NULL,sub,global);
+	pthread_join(t1,&result1);
+	pthread_join(t2,&result2);
+	int n1= result1;
+	int n2= result2;
+	printf("\n\n%d", n1*n2);
+}

Subjects/CSE325 - OPERATING SYSTEMS LABORATORY/End Term Practical Question Paper and Solution/2a.c

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+#include<unistd.h>
+#include<stdio.h>
+#include<stdlib.h>
+#include<string.h>
+#include<fcntl.h>
+int main()
+{
+    FILE *rd;
+    char buffer[50];
+    sprintf(buffer, "Rajat");
+    rd = popen("wc -c","w");
+    fwrite(buffer, sizeof(char), strlen(buffer), rd);
+    pclose(rd);
+}

Subjects/CSE325 - OPERATING SYSTEMS LABORATORY/End Term Practical Question Paper and Solution/2b.c

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+#include<stdio.h>
+#include<unistd.h>
+#include<fcntl.h>
+int main()
+{
+	int fd,n;
+	fd = open("file2.txt",O_RDONLY);
+	char buff[100];
+	int k = lseek(fd,10,SEEK_SET);
+	n = read(fd,buff,15);
+	write(1,buff,n);
+}