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111 changes: 100 additions & 11 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -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.