C/C++ 判断路径为文件

/***************************************************
* 函数说明: 判断当前path参数是否为一个可读的文件
* 函数返回: 0 - 文件刻度 1 - 权限拒绝 -1 -函数错误
*   参 数 : path 文件路径.
***************************************************/
int isReadFile(const char *path)
{
        struct stat info;
        int euid,egid;
        if ( 0!= stat(path,&info) )
        {
                return -1;
        }
        //if it is a file
        if( S_IFREG != (info.st_mode & S_IFMT ) )
        {
                return 1;
        }
        euid=geteuid();//returns the real user ID of the
current process
        egid=getegid();//returns the effective user ID of the
current process
        //if effective user is root
        if(euid==0)
        {
                if(info.st_mode & S_IRUSR || info.st_mode &
S_IRGRP ||info.st_mode & S_IROTH)
                {
                        return 0;
                }