Reads a line from the specified file, up to one less than the
    specified maximum number of characters or up to and including the
    new-line character, whichever comes first. The function stores
    the string in str.
    Format
      #include  <stdio.h>
      char *fgets  (char *str, int maxchar, FILE *file_ptr);
1 – Function Variants
    The fgets function has variants named _fgets32 and _fgets64 for
    use with 32-bit and 64-bit pointer sizes, respectively.
2 – Arguments
 str
    A pointer to a character string that is large enough to hold the
    information fetched from the file.
 maxchar
    The maximum number of characters to fetch.
 file_ptr
    A file pointer.
3 – Description
    The fgets function terminates the line with a null character
    (\0). Unlike gets, fgets places the new-line character that
    terminates the input line into the user buffer if more than
    maxchar characters have not already been fetched.
    When the file pointed to by file_ptr is opened in record
    mode, fgets treats the end of a record the same as a new-line
    character, so it reads up to and including a new-line character
    or to the end of the record.
4 – Return Values
    x                  Pointer to str.
    NULL               Indicates the end-of-file or an error. The
                       contents of str are undefined if a read error
                       occurs.
5 – Example
        #include <stdio.h>
        #include <stdlib.h>
        #include <unixio.h>
        main()
        {
            FILE *fp;
            char c_ptr[130];
            /* Create a dummy data file  */
            if ((fp = fopen("file.dat", "w+")) == NULL) {
                perror("open");
                exit(1);
            }
            fprintf(fp, "this is a test\n") ;
            fclose(fp) ;
            /* Open a file with some data -"this is a test"   */
            if ((fp = fopen("file.dat", "r+")) == NULL) {
               perror("open error") ;
                exit(1);
            }
            fgets(c_ptr, 130, fp);
            puts(c_ptr);        /* Display what fgets got.  */
            fclose(fp);
            delete("file.dat") ;
        }