C fprintf() and fscanf() example函数

int fprintf(FILE *stream, const char *format [, argument, ...])

#include<stdio.h> 
main(){
   FILE *fp;
   fp = fopen("file.txt", "w");//opening file
   fprintf(fp, "Hello file by fprintf...\n");//writing data into file
   fclose(fp);//closing file
}

int fscanf(FILE *stream, const char *format [, argument, ...])

#include<stdio.h>
main(){
   FILE *fp;
   char buff[255];//creating char array to store data of file
   fp = fopen("file.txt", "r");
   while(fscanf(fp, "%s", buff)!=EOF){
   printf("%s ", buff );
   }
   fclose(fp);
}

#include<stdio.h> 
void main()
{
    FILE *fptr;
    int id;
    char name[30];
    float salary;
    fptr = fopen("emp.txt", "w+");/*  open for writing */
    if (fptr == NULL)
    {
        printf("File does not exists \n");
        return;
    }
    printf("Enter the id\n");
    scanf("%d", &id);
    fprintf(fptr, "Id= %d\n", id);
    printf("Enter the name \n");
    scanf("%s", name);
    fprintf(fptr, "Name= %s\n", name);
    printf("Enter the salary\n");
    scanf("%f", &salary);
    fprintf(fptr, "Salary= %.2f\n", salary);
    fclose(fptr);
}