c++ - Check if a file exists without opening it -

how can check if file exists in directory before continuing program? have read answers try opening file using various methods issue of time, file checking corrupt , cant opened. happens in error checking part of program , triggered when error in preceding code has occurred. want check if file exists, if ask delete it, otherwise print out message.

how can go this?

(just deleting , accepting errors work, i'm doing learn, want properly...)

edit:

i have downloaded boost use filesystem library , have compiled it, seemingly no errors, when try compile program, response:

g++ program.cpp -i <path to>/boost_1_54_0 -o output  undefined symbols architecture x86_64: "boost::filesystem::detail::status(boost::filesystem::path const&, boost::system::error_code*)", referenced from:   boost::filesystem::exists(boost::filesystem::path const&)in cc1xx8rd.o "boost::system::system_category()", referenced from:   __static_initialization_and_destruction_0(int, int)in cc1xx8rd.o "boost::system::generic_category()", referenced from:   __static_initialization_and_destruction_0(int, int)in cc1xx8rd.o ld: symbol(s) not found architecture x86_64 collect2: ld returned 1 exit status 

the places use boost in program are:

boost::filesystem::path my_file(s4); if (boost::filesystem::exists(my_file)){ ... 

use stat() or access():

#include <unistd.h>  int res = access(path, r_ok); if (res < 0) {     if (errno == enoent) {          // file not exist     } else if (errno == eacces]) {          // file exists not readable     } else {          // fail     } }