fread example in C

Header file:

    stdio.h

Synopsis:

     size_t fread(void *ptr, size_t size_of_nobj, size_t nobj, FILE *stream);

Description:

    Reads nobj of data, each of size sizeof_of_nobj from the stream and stores them in ptr.  Returns number of objects read on success.  Otherwise, feof or ferror is returned.

fread function C example:

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

  int main() {
        char *ptr, *str;
        int nobj, ret, size;
        FILE *fp;
        fp = fopen("mastering-c.txt", "rb");
        if (fp == NULL) {
                str = strerror(errno);
                perror(str);
                return;
        }

        ret = fseek(fp, 0, SEEK_END);
        if (ret != 0) {
                str = strerror(errno);
                perror(str);
                return;
        }
        nobj = ftell(fp);  // number of characters
        size = sizeof(char);
        rewind(fp);
        ptr = (char *) malloc(sizeof(char) * size);
        ret = fread(ptr, size, nobj, fp);
        if (ret != nobj) {
                str = strerror(errno);
                perror(str);
                return;
        }

        printf("ret: %d\tnobj: %d\nFile contents:\n%s", ret, nobj, ptr);
        return 0;
  }

  Output:

  jp@jp-VirtualBox:~/cpgms/exp$ ./a.out
  ret: 75    nobj: 75
  File contents:
  Hello world
  This is fread example program in C
  Thanks for visiting our blog
  jp@jp-VirtualBox:~/cpgms/exp$ cat mastering-c.txt
  Hello world
  This is fread example program in C
  Thanks for visiting our blog