1.C++很简单的一种办法：
#include <iostream> #include <fstream> using namespace std; #define FILENAME "stat.dat" int main() { fstream _file; _file.open(FILENAME,ios::in); if(!_file) { cout<<FILENAME<<"没有被创建"; } else { cout<<FILENAME<<"已经存在"; } return 0; } |
2.利用 c 语言的库的办法：
函数名: access
功 能: 确定文件的访问权限
用 法: int access(const char *filename, int amode);
以前一直没用过这个函数,今天调试程序发现了这个函数,感觉挺好用,尤其是判断一个文件或文件夹是否存在的时候,用不着再find了,文件的话还可以检测读写权限,文件夹的话则只能判断是否存在,下面摘自MSDN：
int_access(constchar*path,intmode); ReturnValue Eachofthesefunctionsreturns0ifthefilehasthegivenmode.Thefunctionreturns–1ifthenamedfiledoesnotexistorisnotaccessibleinthegivenmode;inthiscase,errnoissetasfollows: EACCES Accessdenied:file’spermissionsettingdoesnotallowspecifiedaccess. ENOENT Filenameorpathnotfound. Parameters path Fileordirectorypath mode Permissionsetting Remarks Whenusedwithfiles,the_accessfunctiondetermineswhetherthespecifiedfileexistsandcanbeaccessedasspecifiedbythevalueofmode.Whenusedwithdirectories,_accessdeterminesonlywhetherthespecifieddirectoryexists;inWindowsNT,alldirectorieshavereadandwriteaccess. modeValueChecksFileFor 00Existenceonly 02Writepermission 04Readpermission 06Readandwritepermission Example /*ACCESS.C:Thisexampleuses_accesstocheckthe *filenamed"ACCESS.C"toseeifitexistsandif *writingisallowed. */ #include<io.h> #include<stdio.h> #include<stdlib.h> voidmain(void) { /*Checkforexistence*/ if((_access("ACCESS.C",0))!=-1) { printf("FileACCESS.Cexists"); /*Checkforwritepermission*/ if((_access("ACCESS.C",2))!=-1) printf("FileACCESS.Chaswritepermission"); } } Output FileACCESS.CexistsFileACCESS.Chaswritepermission |
