#include<stdio.h>
          #include<stdlib.h>
          #include<assert.h>
          void main(int argc,char *argv[])
      {
        FILE * p=0;
        int line=0,count=0;
        char * buf[1024];
        char * charbuf=0,*fp;
        memset(buf,0x00,sizeof(buf));
        p=fopen(argv[3],"r+");
        buf[0]='1';
        //查看文件行數(shù)，準(zhǔn)備給其分配內(nèi)存
        while(*buf!='\0')
        {
            memset(buf,0x00,sizeof(buf));
            fgets(buf,1024,p);
            line++;
        }

        {
           char *charbuf=(char*)malloc(line*1024); //分配相應(yīng)內(nèi)存
           assert(charbuf);
           fp=charbuf;
           fseek(p,SEEK_SET,0);
           buf[0]='1';
           count=0;
           while(*buf!='\0') //將指定文件讀入內(nèi)存
           {
                memset(buf,0x00,sizeof(1024));
                fgets(buf,1024,p);
                strncpy(fp,buf,strlen(buf));
                fp=fp+strlen(buf);
           }

           fclose(p);
           p=0;
           p=fopen(argv[3],"w+");
           for(count=0;count<line*1024;count++)
           {
      //      if(*(charbuf+count*1024)=='\0')break;
      //      fwrite(charbuf+count*1024,1024,1,p);
            if( *(charbuf+count)=='\0') break;
            if(strncmp(charbuf+count,argv[1],strlen(argv[1]))==0)
                {fwrite(argv[2],strlen(argv[2]),1,p);count=count+strlen(argv[1])-1;}
            else
                fwrite(charbuf+count,1,1,p);

           }
        }
   close(p);
   p=0;
   free(charbuf);
   charbuf=0;
}