在这里插入代码片
```//行编辑器 
#include<stdio.h>
#include<stdlib.h>
#include<string.h>#define MAXLEN 256   //每行存储字符数void openFile();
void closeFile();
void saveFile();
void listLines();
void gotoLine();
void insertString();
void deleteString();
void showHelp();
void countLine();
void enterFileNmae();
void clearBuffer();
void interPosition(int *,int *);char fname[256]="";
char (*buf)[MAXLEN]=NULL;
int lines=0;//菜单
int main()
{
char cmd[20];
while(1){printf("comand:");scanf("%s",cmd);if(strcmp(cmd,"fopen")==0)   		openFile();else  if(strcmp(cmd,"fcolse")==0)   closeFile();else if(strcmp(cmd,"fsave")==0)     saveFile();else if(strcmp(cmd,"list")==0) 		listLines();else if(strcmp(cmd,"gotoln")==0) 	gotoLine();else if(strcmp(cmd,"inss")==0) 		insertString();else if(strcmp(cmd,"dels")==0) 		deleteString();else if(strcmp(cmd,"help")==0) 		showHelp();else if(strcmp(cmd,"exit")==0) 		break;else								printf("%s?\n",cmd);	//输入错误命令时处理； }	clearBuffer();return 0; 
} //文件名输入
void enterFileNmae()
{printf("filename:");scanf("%s",fname);
}
//文件中数据行的数计算 
void countLines()
{FILE *fp;char s[MAXLEN];lines=0;fp=fopen(fname,"r");//读取模式if(fp==NULL)	return ;while(fgets(s,MAXLEN-1,fp)){lines++;printf("m=%d\n",lines);fclose(fp);	}	
}
//指针变量，文件名以及行数的初始化 
void clearBuffer()
{fname[0]='\0';//文件名是空的 lines=0;if(buf)	free(buf);buf=NULL;
}//分配内存，读入文件
void openFile()
{int n=0;FILE *fp;char *myline;enterFileNmae();countLines();//countLine();buf=(char(*)[MAXLEN])malloc(sizeof(char) * lines * MAXLEN);if(!buf) 	return ;fp=fopen(fname,"r");if(fp=NULL){clearBuffer();return ;}while(fgets(buf[n],MAXLEN-1,fp)){myline=buf[n];//数据复制到缓存单元中myline[strlen(myline-1)]='\0';n++; }fclose(fp);printf("读入%d行。\n",lines);
} //内存释放 
void closeFile()
{char ans[20]=" ";printf("是否保存？(Y or N)");scanf("%s",ans);if(ans[0]=='y') saveFile();clearBuffer();printf("以释放内存。\n"); 
}
//保存文件 
void saveFile()
{int n;FILE *fp;enterFileNmae();	//input the file name;fp=fopen(fname,"w") ; //writing if(fp==NULL) return ;for(n=0;n<lines;n++)	fprintf(fp,"%s\n",buf[n]);	//output on the filefclose(fp);	//close the file;printf("已保存。、n"); 
}//所有行的显示 
void listLines()
{int n;for(n=0;n<lines;n++)	printf("%04d:%s\n",n,buf[n]);
}
//指定行的显示 
void gotoLine()
{int n;printf("换行");scanf("%d",&n);if(0<=n && n<lines)	printf("%04d:%s\n",n,buf[n]);
}
//字符串插入位置的输入 
void interPosition(int *prow,int *pcol)
{int row, col, characters;*prow = *pcol = 0;printf("行号:");scanf("&d", &row);if(row<0 || row >= lines)	//检查变量row的数值范围。return;characters = strlen(buf[row]);printf("位数:");scanf("%d", &col);if(col <0 ||col >= characters)		//检查变量co1的数值范围。return;*prow = row;*pcol = col;
} 
//字符串的插入
void insertString()
{int row, col;			//行号.位数char insstr[MAXLEN];	//待插入的字符串char newstr [MAXLEN];	//插入后的字符串char *myline;			//目标行interPosition(&row, &col);myline = buf[row];printf("插入字符串:");scanf("&s",insstr);/*指定行的字符串长度与插入的字符串长度之和大于内存单元的最大字符数时，返回main()函数。*/if(strlen(myline) + strlen(insstr) >= MAXLEN)return;sprintf (newstr, "%s%s",insstr, myline + col);strcpy (myline + col, newstr);printf("第&d行第&d个字符后插入\"&s\"\n", row, col, insstr);printf("&04d:8s\n", row, myline);
}//字符串的删除void deleteString(){int row, col;//行号,位数int delnum;//删除的字符串数char *myline;	 //目标行int mylength; 	// 目标行字符串的长度int i	;		//计数器//interPosition(int *prow,int *pcol);interPosition(&row, &col);myline = buf[ row];mylength = strlen (myline);printf("字符数:");scanf("&d", &delnum);if(delnum <= 0 || mylength < col + delnum)	//检查删除字符数的数值范围。return;for(i = col; i <= mylength - delnum; i++)	//删除指定字符。myline[i] = myline[i + delnum];printf("从第%d行的第%d个字符后开始删除%d个字符。\n", row, col,delnum);printf("%04d:%s\n",row,myline);//行,线)
}
//帮助信息的显示void showHelp()
{printf(" COMMAND HELP 		:\"help\"\n");printf( "LOAD FILE			:\"fopen\"\n") ;printf("RELEASE BUFFER		:\"fclose\"\n");printf("SAVE FILE			:\"fsave\"\n");printf("SHOW ALL LINES 		:\"list\"\n");printf("SHOW SINGLE LINE 	:\"gotoln\"\n");printf ("INSERT STRING		:\"inss\"\n");printf("DELETE STRING		:\"dels\"\n");
}