From 90740df1cd2d97c6c6165ea47c3cd5390765a3c3 Mon Sep 17 00:00:00 2001
From: Saranya <144870813+Saranyaaav@users.noreply.github.com>
Date: Sun, 12 May 2024 20:52:10 +0530
Subject: [PATCH] Update README.md

---
 README.md | 111 ++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 100 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index d38d99b..2f63316 100644
--- a/README.md
+++ b/README.md
@@ -20,23 +20,112 @@ Execute the C Program for the desired output.
 # PROGRAM:
 
 ## 1.To Write a C program that illustrates files copying 
-
-
-
-
-
-
+```
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h> // Include for debugging
+
+int main() {
+    char block[1024];
+    int in, out;
+    int nread;
+
+    // Open input file
+    in = open("filecopy.c", O_RDONLY);
+    if (in == -1) {
+        perror("Error opening input file");
+        exit(1);
+    }
+    printf("Input file opened successfully\n");
+
+    // Open or create output file
+    out = open("file.out", O_WRONLY|O_CREAT, S_IRUSR|S_IWUSR);
+    if (out == -1) {
+        perror("Error opening/creating output file");
+        exit(1);
+    }
+    printf("Output file opened/created successfully\n");
+
+    // Read from input file and write to output file
+    while ((nread = read(in, block, sizeof(block))) > 0) {
+        printf("Read %d bytes from input file\n", nread);
+        if (write(out, block, nread) != nread) {
+            perror("Error writing to output file");
+            exit(1);
+        }
+        printf("Wrote %d bytes to output file\n", nread);
+    }
+
+    if (nread == -1) {
+        perror("Error reading from input file");
+        exit(1);
+    }
+
+    printf("End of input file\n");
+
+    // Close files
+    close(in);
+    close(out);
+
+    printf("Files closed successfully\n");
+
+    exit(0);
+}
+```
 
 ## 2.To Write a C program that illustrates files locking
-
-
-
+```
+//C program that illustrates files locking goes here
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/file.h>
+int main (int argc, char* argv[])
+{ char* file = argv[1];
+int fd;
+struct flock lock;
+printf ("opening %s\n", file);
+/* Open a file descriptor to the file. */
+fd = open (file, O_WRONLY);
+// acquire shared lock
+if (flock(fd, LOCK_SH) == -1) {
+printf("error");
+}else
+{printf("Acquiring shared lock using flock");
+}
+getchar();
+// non-atomically upgrade to exclusive lock
+// do it in non-blocking mode, i.e. fail if can't upgrade immediately
+if (flock(fd, LOCK_EX | LOCK_NB) == -1) {
+printf("error");
+}else
+{printf("Acquiring exclusive lock using flock");}
+getchar();
+// release lock
+// lock is also released automatically when close() is called or process exits
+if (flock(fd, LOCK_UN) == -1) {
+printf("error");
+}else{
+printf("unlocking");
+}
+getchar();
+close (fd);
+return 0;
+}
+```
 
 ## OUTPUT
 
+### FILECOPYING
+![Screenshot from 2024-05-07 13-18-53](https://github.com/gowriganeshns/Linux-File-IO-Systems-locking/assets/144870813/e540eaf9-f56a-44a0-bfc8-cb81948f6d75)
+![Screenshot from 2024-05-07 13-22-21](https://github.com/gowriganeshns/Linux-File-IO-Systems-locking/assets/144870813/08c8e46d-afc4-4763-afca-01def1469d8e)
+![Screenshot from 2024-05-07 13-23-08](https://github.com/gowriganeshns/Linux-File-IO-Systems-locking/assets/144870813/ca463491-3e57-4d3e-bf02-1487f7e7f4a2)
 
-
-
+### FILELOCKING
+![Screenshot from 2024-05-07 13-27-18](https://github.com/gowriganeshns/Linux-File-IO-Systems-locking/assets/144870813/036e0d2c-837b-4a91-841f-eff9d646d9b7)
 
 # RESULT:
 The programs are executed successfully.