I have a C++ project that I haven't used in a year. It used to run perfectly, opening files with:
Matrix pmatrix;
pmatrix.readFromFile("pmtx.txt");
and in the function:
void Matrix::readFromFile(string filename){
ifstream tmfile;
tmfile.open(filename.c_str());
if (!tmfile) {
cout << "unable to open tm file";
//return 1;
}
etc
}
It keeps telling me "unable to open tm file". I've been breaking my head about this. Obviously the file is in the directory of the src and I copied it to Debug and Release, I gave it full permissions. I use eclipse.
Any ideas why this just stopped working?
There was something strange screwed up with the eclipse project. I created a new project, copied in existing files and it worked.
Related
I'm using Netbeans 8.2 and I am programming with C++.
I'm trying to read a file. I have put it in the correct project folder of sources and I have used #include <fstream> .
ifstream myfile ("figures.txt");
code...
myfile.close();
I have the file in the correct place. But this message pops up:
Unrecognized file
Then, my other part of code also gives me error, because never detects the file I'm talking about open.
if (myfile.is_open()){
code...
}else{
cout << "file not open" << endl;
}
Auto solved, the .txt must be in the project folder, not in nbproject folder. At least it has worked doing it this way. Any more reccomendations will be accepted!
The title is a bit long-winded, but basically, I've written an app that reads and writes its input and output to text files. The entire time, it would read and write the files directly in the same directory as my Xcode derived data->project->build->products->debug folder. This was where everything was being written to and read from. I don't have a custom path set up for the application, so it just saves wherever the app is located. For the first time ever, I ran Apple's Instruments app, to try to learn how to use a profiler. Not long after selecting this app as the target in Instruments, I went back to the Xcode app to run the program some more. Everything works fine in Xcode. It reads from the files and prints to files in the same location as the folder, but if I try to run the actual program itself by clicking on the file and having it open terminal, it no longer reads or prints to the directory that app is in. Instead, its printing and reading from my home folder. I don't know what changed or what caused it to change, but I'm hoping its a simple fix. I'd like for the application to read from files and print files from the directory its located in again. I'm not sure if its an Xcode setting or a Terminal setting.
Any help would be greatly appreciated.
Update 1: Tried this with no luck:
how to change the working directory to the location of the program
The directory field was blank, so I thought this would the solution, but filling it in with the suggestion did nothing to alleviate the issue.
Update 2:
Just tried deleting the preference file, still no solution. I'm willing to give someone reputation. I don't have a whole lot because I'm a newer member, but I'll give what the person thinks is fair, to whoever solves it. I'm desperate and really don't want to wait 2 days to have this issue solved.
Update 3:
Tried changing the default path in the "Profile (release)->options area in the scheme section to the default variable suggested in update 1. No luck. I'm beginning to lose my mind.
Update 4:
I've tried deleting the scheme entirely and making a new one, in hopes that maybe there was something botched with the scheme, but this did not solve the issue. Input and output while running the app in Xcode is still using the working directory, while running the executable in the debug folder is using the home folder.
Update 5:
Just tested this on an older iMac and Xcode setup (OS 10.8.5 and Xcode 5.1.1) and it seems to be working correctly, reading and writing to the current working directory of the application in the debug folder.
For whatever reason, the solution suggested by https://stackoverflow.com/a/15537436/1035008 no longer works. Maybe broken in Xcode 8.1. But this seems to work:
#include <iostream>
#include <fstream>
#include <unistd.h>
using namespace std;
int main (int argc, const char * argv[])
{
// argv[0] returns the full path to the program, in my case "/Users/yuchen/Library/Developer/Xcode/DerivedData/../Debug/test
string directory(argv[0]);
// And we want to get rid of the program name `test`
directory = directory.substr(0, directory.find_last_of("/"));
// Point the directory to the program directory
chdir(directory.c_str());
cout << "Current directory is: " << getcwd(NULL, 0) << endl; // /Users/yuchen/Library/Developer/Xcode/DerivedData/../Debug/
ifstream fin("hi.txt");
if (fin.is_open()) cout << "File is Open" << endl;
else cout << "File is not open" << endl;
fin.close();
return 0;
}
Also see SO and SO. Hope this helps.
Like the questioner in "New to Xcode can't open files in c++?" I'm learning Xcode and OS X (I'm using Xcode 7 on a Yosemite mac).
I can get the code to work perfectly when I build and run it, but can't get the executable to work when I try to run it as a stand alone program.
I'm trying to translate some games I've written on a PC in C++ using SFML.
There has to be a way to save high scores and previous games within an app, but this has me stymied.
This is the sample code I used based on the previous question:
#include <string>
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
ifstream fin;
ofstream fout;
string input;
fin.open("inputFile.txt");
if(fin.fail())
cout << "File failed to open." << endl;
fin >> input;
fin.close();
fout.open("outputFile.txt");
fout << input;
fout << "\n Data transferred \n";
fout.close();
}
This works perfectly when I build and run it, so I've got the proper path to the desktop folder set up. (I'm putting the data files in the same folder as the executable and specifying the path in Xcode.)
No problems when I run this within Xcode, but this is the message on the terminal console when I run the executable by itself:
"…/Desktop/datafiles/Build/Products/Debug/datafiles ; exit;
…/Desktop/datafiles/Build/Products/Debug/datafiles ; exit;
File failed to open.
logout
Saving session...
...copying shared history...
...saving history...truncating history files...
...completed.
[Process completed]"
Is there another flag or path that needs to be set within Xcode for this to work? Two other related questions: How do I access the terminal history to see what is going on? Finally, if I set up the project as an SFML app instead of a terminal project (command line tool app), why can't I see the files within the SFML app, even though I've set the command line flag to see hidden files, and I can see other hidden files on my hard drive? I can see the files if I open the SFML app folder in Windows, so I know they are there.
This is my first question on Stack Overflow, so apologies if this should be appended to the previous question, but this doesn't appear to be an answer to me, but is quite a different version of the original question that is not addressed in the answers.
Thanks!
I know there are a ton of questions pertaining to this subject but I cannot get this to work. The program ran fine on my laptop, but when I try to compile and run it in the the schools Linux lab the program cannot open the file. I have tried defining the absolute file position but nothing has worked. The file name is correct and everything but when I try to run the program it displays "failed". I'm using gedit and compiled the program with bash.
ifstream fin("rainfall.dat"); // If the file cannot open display failed
if(fin.fail()){
cout << "failed" << endl;
return 1;
}
try
#include <errno.h>
if(fin.fail())
perror("open failed ");
this will give you a human readable message for the last error
I am having a strange issue. I have a function (writedata) that take a string and writes it to a file. Is works fine and files are created when I build and run the program within xCode.
When I export the compiled project from xCode and just try to run the executable terminal app no file is ever written. I can see the process completes in terminal with no errors given. I even get the 'cout<<"Done. File Written!"' message but no file.
void writedata(string writedata, string filename){
ofstream data(filename, ios::app);
if (data.is_open())
{
data<<writedata;
cout<<"Done. File Written!";
data.close();
}
else cout << "Unable to open file";
data.close();
}
Does anyone know why this is happening?