// 读一个字符
#include "stdio.h"
#include "string.h"
main()
{
    FILE *fp;
    char c;
    if((fp=fopen("s.c","r"))==NULL)
    {
        printf("File can not open!");
        getch();
        exit(0);
    }
    while(!feof(fp))
    {
        c=fgetc(fp);
        putchar(c);
    }
    fclose(fp);
    getch();
    system("pause");
}

// 写一个字符
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
main()
{
    FILE *fp;
    char c;
    if((fp=fopen("d:\\data.txt","w"))==NULL)
    {
        printf("\nFile can not open!");
        getchar();
        exit(0);
    }
    while((c=getchar())!='#')
    {
        fputc(c,fp);
    }
    fclose(fp);
}

/*读写字符串*/
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
main(){
    FILE *fp;
    char c[80]={""},s[80]={""};
    /*写字符串*/
    if((fp=fopen("d:\\data.txt","w"))==NULL)
    {
        printf("\nFile can not open!");
        exit(0);
    }
    gets(c);
    fputs(c,fp);
    fclose(fp);
    /*读字符串*/
    if((fp=fopen("d:\\data.txt","r"))==NULL)
    {
        printf("\nFile can not open!");
        exit(0);
    }
    while(!feof(fp))
    {
        fgets(s,80,fp);
        puts(s);
    }
    fclose(fp);
    getchar();
}

新来的，不懂规矩，还望兄弟多多指点。我只是转一篇帖子，实用，论坛上是不是都只提问而不可以这样啊？