#include<stdio.h>#include<stdlib.h>#include<windows.h>intfile_size(char*filename)//獲取檔名為filename的檔案大小。{FILE*fp=fopen(filename,"rb");//開啟檔案。intsize;if(fp==NULL)//開啟檔案失敗return-1;fseek(fp,0,SEEK_END);//定位檔案指標到檔案尾。size=ftell(fp);//獲取檔案指標偏移量，即檔案大小。fclose(fp);//關閉檔案。returnsize;}intmain(){intsize=0;size=file_size("qw");printf("%d\n",size);FILE*pFile,*qw;char*buffer=(char*)malloc(sizeof(char)*size);qw =fopen("qw","r");pFile=fopen("qwe","wb");printf("%d==\n",pFile);printf("%d\n",size);fread(buffer,1,size,qw);fwrite(buffer,sizeof(byte),size,pFile);fclose(pFile);rename("qwe","Groot.jpg");return0;}擴充套件資料：c語言讀取TXT檔案：#include<stdio.h>#include<stdlib.h>#include<string.h>#defineMAX_LINE1024intmain(){ charbuf[MAX_LINE]; /*緩衝區*/ FILE*fp; /*檔案指標*/ intlen; /*行字元個數*/ if((fp=fopen("test.txt","r"))==NULL) { perror("failtoread"); exit(1); } while(fgets(buf,MAX_LINE,fp)!=NULL) { len=strlen(buf); buf[len-1]="\0"; /*去掉換行符*/ printf("%s%d\n",buf,len-1); }return0;}