c programming problem
i' wote a code for calculating checksum of file. but when i compile it it shows me
problems which i's unable to resolve . 

my code for calculating checksum is following:

#include <stdio.h>
#include<stdlib.h>

unsigned checksum(void *buffer, size_t len, unsigned int seed)

{
      unsigned char *buf = (unsigned char *)buffer;
      size_t i;

      for (i = 0; i < len; ++i)
            seed += (unsigned int)(*buf++);
      return seed;
}


 int main()
{
      FILE *fp;
      size_t len;
      char buf[4096], file[] = "/home/manish.yadav/filename.c";

      if (NULL == (fp = fopen(file, "rb")))
      {
            printf("Unable to open %s for reading\n", file);
            return -1;
      }
      len = fread(buf, sizeof(char), sizeof(buf), fp);
      printf("%zd bytes read\n", len);
      printf("The checksum of %s is %u\n", file, checksum(buf, len, 0));
  
return 0 ;
}

i saved it with name checksum .c 
i compiled it from folowing command :
gcc checksum.c
i got the following msg :




c programming problem
===

i' wote a code for calculating checksum of file. but when i compile it it shows me
problems which i's unable to resolve . 

my code for calculating checksum is following:

#include <stdio.h>
#include<stdlib.h>

unsigned checksum(void *buffer, size_t len, unsigned int seed)

{
      unsigned char *buf = (unsigned char *)buffer;
      size_t i;

      for (i = 0; i < len; ++i)
            seed += (unsigned int)(*buf++);
      return seed;
}


 int main()
{
      FILE *fp;
      size_t len;
      char buf[4096], file[] = "/home/manish.yadav/filename.c";

      if (NULL == (fp = fopen(file, "rb")))
      {
            printf("Unable to open %s for reading\n", file);
            return -1;
      }
      len = fread(buf, sizeof(char), sizeof(buf), fp);
      printf("%zd bytes read\n", len);
      printf("The checksum of %s is %u\n", file, checksum(buf, len, 0));
  
return 0 ;
}

i saved it with name checksum .c 
i compiled it from folowing command :
gcc checksum.c
i got the following msg :



