9.c

C语言下实现的小型文本编辑器．能够添加删除文件。能够删除行添加行

#include   "stdio.h"   
  #include   "stdlib.h"   
  struct   line{   
      char   text[81];   
      int   num;                                 /*行号*/   
      struct   line   *next;             /*指向下一个输入项目的指针   */   
      struct   line   *prior;           /*指向前一个项目的指针   */   
  };   
  struct   line     *start;             /*指向表中第一个项目的指针   */   
  struct   line     *last;               /*指向表中作后一个项目的指针   */   
  struct   line     *find(int),*dls_store(struct   line   *);   
  void   patchup(int,int),delete_text(),list(),save(char   *),load(char   *);   
  menu_select();   
  enter(int   linenum);   
    
  void   main(int   argc,char   *argv[])   
  {   
      char   s[80],choice,fname[80];   
    //   struct   line   *info;   
      int   linenum=1;   
      start=NULL;   
      last=NULL;   
      if(argc==2)   load(argv[1]);/*装入命令行上的文件   */   
      do{   
                    choice=menu_select();   
                    switch(choice){   
                                        case   1:printf("\thanghao：");   
                                                                      gets(s);   
                                                                      linenum=atoi(s);   
                                                                      enter(linenum);   
                                                                      break;   
                                        case   2:delete_text();   
                                                                      break;   
                                        case   3:list();   
                                                                      break;   
                                        case   4:printf("\twenjianming：");   
                                                                      gets(fname);   
                                                                      save(fname);   
                                                                      break;   
                                        case   5:printf("\twenjianming：");   
                                                                      gets(fname);   
                                                                      load(fname);   
                                                                      break;   
                                        case   6:exit(0);   
                                  }   
                        }while(1);   
  }   
    
  /*   显示菜单，供用户选择   */   
  menu_select()   
  {   
      char   s[80];   
      int   c;   
      printf("\t\t1.putin\n");   
      printf("\t\t2.shangshuyiahng\n");   
      printf("\t\t3.xianshiyihang\n");   
      printf("\t\t4.chuanpan\n");   
      printf("\t\t5.zairu\n");   
      printf("\t\t6.tuichu\n");   
      do{   
                      printf("\n\n\t\tshuzixuanzhe：");   
                      gets(s);   
                      c=atoi(s);   
                  }while(c<0||c>6);   
      return(c);   
  }   
    
  /*将文本插在指定行端部     */   
  enter(int   linenum)   
  {   
      struct   line   *info;   
      //char   t[81];   
      for(;;){   
                    /*     */   
                    info=(struct   line   *)malloc(sizeof(struct   line));   
                    if(!info){   
                                    printf("\t!   neichunbugou！\n");   
                                    return(NULL);   
      }   
      printf("%d:",linenum);   
      gets(info->text);   
      info->num=linenum;   
      if(*info->text){   
                  if(find(linenum))   patchup(linenum,1);   
                  if(*info->text)   start=dls_store(info);   
      }   
      else   break;   
      linenum++;   
      }   
      return(linenum);   
  }   
    
  /*当文本内容插在文件中间时其下面的内容的行号必须增加1，而     */   
  /*删除时，被删除的文本后面的行号必须减1   */   
  void   patchup(int   n,int   incr)   
  {   
      struct   line   *i;   
      i=find(n);   
      while(i){   
                  i->num=i->num+incr;   
                  i=i->next;   
        }   
  }   
  /*按行号排序后插入   */   
  struct   line   *dls_store(struct   line   *i)   
  {   
      struct   line   *old,*p;   
      if(last==NULL){   
                        i->next=NULL;   
                        i->prior=NULL;   
                        last=i;   
                        return(i);   
        }   
      p=start;   
      old=NULL;   
      while(p){   
                        if(p->num){   
                                      old=p;   
                                      p=p->next;   
                        }   
                        else{   
                                      if(p->prior){   
                                                    p->prior->next=i;   
                                                    i->next=p;   
                                                    p->prior=i;   
                                                    return   start;   
                                        }   
                                      i->next=p;   
                                      i->prior=NULL;   
                                      p->prior=i;   
                                      return(i);   
                        }   
                      }   
        old->next=i;   
        i->next=NULL;   
        i->prior=old;   
        last=i;   
        return   start;   
  }   
    
  /*删除一行   */   
  void   delete_text()   
  {   
      struct   line   *info;   
      char   s[80];   
      int   linenum;   
      printf("\thanghao:");   
      gets(s);   
      linenum=atoi(s);   
      info=find(linenum);   
      if(info){   
                  if(start==info){   
                                  start=info->next;   
                                  if(start)   start->prior=NULL;   
                                  else       last=NULL;   
                        }   
                  else{   
                        info->prior->next=info->next;   
                        if(info!=last)   
                                      info->next->prior=info->prior;   
                        else   last=info->prior;   
                    }   
                  free(info);   
                  patchup(linenum+1,-1);   
      }   
  }   
    
  /*查找一行文本     */   
  struct   line   *find(int   linenum)   
  {   
      struct   line   *info;   
      info=start;   
      while(info){   
                  if(linenum==info->num)   return(info);   
                  info=info->next;   
      }   
      return(NULL);   
  }   
    
  /*显示文本     */   
  void   list()   
  {   
      struct   line   *info;   
      info=start;   
      while(info){   
                  printf("%d:%s\n",info->num,info->text);   
                  info=info->next;   
      }   
      printf("\n\n");   
  }   
    
  /*存文件   */   
  void   save(char   *fname)   
  {   
      struct   line   *info;   
      char   *p;   
      FILE   *fp;   
      if((fp=fopen("text.txt","w"))==NULL){   
                  printf("\tdabukai！\n");   
                  exit(0);   
      }   
      printf("\tcunruing：\n");   
      info=start;   
      while(info){   
                                  p=info->text;   
                                  while(*p)   putc(*p++,fp);   
                                  //putc('\r',fp);   
                                  putc('\n',fp);   
                                  info=info->next;   
        }   
      fclose(fp);   
  }   
    
  /*装入文件   */   
  void   load(char   *fname)   
  {   
      struct   line   *info,*temp;   
      char   *p;   
      FILE   *fp;   
      //int   t,size,inct;   
      int   size,inct;   
      if((fp=fopen("text.txt","r"))==NULL){   
                  printf("\tdabukai！\n");   
                  exit(0);   
      }   
      while(start){   
                                  temp=start;   
                                  start=start->next;   
                                  free(temp);   
        }   
        printf("\n\tining   ！\n");   
        size=sizeof(struct   line);   
        start=(struct   line*)malloc(size);   
        if(!start){   
                                    printf("\n\t内存已经用完！");   
                                    return;   
        }   
        info=start;   
        p=info->text;   
        inct=1;   
        while((*p=getc(fp))!=EOF){   
                        p++;   
                        while((*p=getc(fp))!='\n')   p++;   
                        //getc(fp);             /*丢掉'\n'     */   
                        *p='\0';   
                        info->num=inct++;   
                        info->next=(struct   line*)malloc(size);   
                        if(!info->next){   
                                    printf("\n\t内存已经用完！");   
                                    return;   
                        }   
                        info->prior=temp;   
                        temp=info;   
                        info=info->next;   
                        p=info->text;   
                  }   
                  temp->next=NULL;   
                  last=temp;   
                  free(info);   
                  start->prior=NULL;   
                  fclose(fp);   
  }