My ifstream doesn't seem to be working

This is a main file that I am using to test methods before I implement them. I am trying to get the list of all files in a directory, write them to a txt file (It works fine until here), then read the file names from that text file.

using namespace std;

string sysCall = "", location = "~/Documents/filenames.txt"开发者_JS百科;
string temp = "";
sysCall = "ls / > "+location;
system(sysCall.c_str());

ifstream allfiles(location.c_str());
allfiles.good();
getline(allfiles, temp);
cout<<temp<<endl;  //At this point, the value of temp is equal to ""

return -1;

After the program runs, no text has been outputted. From what I've read in other peoples' questions, this should work (but obviously doesn't). What am I doing wrong here?

EDIT: allfiles.good() returns false, but I don't understand why it would return that...

ifstream allfiles("~/Documents/filenames.txt"); doesn't do what you think it does. The tilde ~ character is not part of the filename -- it is a special character interpreted by some shells. You need the entire path, with no ~ or $ characters in it.

Try setting location to "/tmp/filenames.txt", or just "filenames.txt".

Also, if Boost.Filesystem is available to you, you could use a directory_iterator instead of invoking /bin/ls.

I'll bet the system() call expands the ~ in the filename to your home directory (e.g. /home/mrswmmr), but ifstream does not. Replace the ~ with the full path to your home directory and it should work.

It has no guarantee to work because system gives no guarantee.