行编辑程序.txt

行编辑程序

//行编辑程序
#include <stdio.h>
#define Stack_Size 100
#define MAX 500
typedef struct {
        char *top;
        char *base;
        int stacklength;
        }Sqstack,*Pstack;

                                       
 void InitStack(Pstack S)
      {
           S->base=(char *)malloc( Stack_Size*sizeof(char));
           if(!S->base)
               exit(1);
            S->top=S->base;
            S->stacklength=Stack_Size;
      }
void Push(Pstack S,char ch)
      {
           if(S->top-S->base>=Stack_Size)
               exit(1);
           *(S->top++)=ch;
      }
void Pop(Pstack S)
      { 
            if(S->base==S->top)
              exit(1);
             S->top--;
      }
 /*int PopGet(Pstack S,char *ch)
      { 
            if(S->base==S->top)
              exit(1);
              *ch=*(--S->top);
      } */
void Clear(Pstack S)
     {
           S->base=S->top;
     }  
 void Destroy(Pstack S)
      {
               free(S->base);
               S->top=S->base;
      }            
     
                                
int main()
{
    int i,j;
    char ch;
    Sqstack S;
    char *p;   //注意类型 
    char Array[MAX];        
    FILE *fp;
    InitStack(&S);     
    printf("please input string:\n");
    while((ch=getchar())!='\n') {
           switch(ch) {
                      case'#':Pop(&S);
                              break;
                      case'@':Clear(&S);
                              break;
                      default:Push(&S,ch);
                             
                      }
           } 
    for(p=S.base,i=0;p<S.top;p++,i++)
          Array[i]=*p;
                                     
    if((fp=fopen("myfile.txt","ab"))==NULL)
         {
                  printf("Can  not open the file!\n");                      
                  exit(1); 
         }
     for(j=0; j<i;j++)
          fputc(Array[j],fp);
       fputc('\n',fp); //在输入完一段数据之后输入一个回车给磁盘文件         
     Destroy(&S);   
     fclose(fp); //否则提示:另一个程序正在使用此文件，进程无法访问  
        return 0;
}