Reading data under Linux

[paultawk]

I have written a prog to read data from files but it only works under windows.
Can anyone tell me how to read data under Linux?

I would need somehting similar to the following windows code, but that works under Linux:

#include <iostream>
using std::cerr;
using std::cout;
using std::endl;
#include <fstream>
using std::ifstream;
#include <cstdlib> // for exit function
// This program reads values from the file 'example.dat'
// and echoes them to the display until a negative value
// is read.
int main()
{
ifstream indata; // indata is like cin
int num; // variable for input value
indata.open("ex ample.dat"); // opens the file
if(!indata) { // file couldn't be opened
cerr << "Error: file could not be opened" << endl;
exit(1);
}
indata >> num;
while ( !indata.eof() ) { // keep reading until end-of-file
cout << "The next number is " << num << endl;
indata >> num; // sets EOF flag if no value found
}
indata.close();
cout << "End-of-file reached.." << endl;
return 0;
}

best regards

[arne]

I have written a prog to read data from files but it only works under windows.
Can anyone tell me how to read data under Linux?

I would need somehting similar to the following windows code, but that works under Linux:

#include <iostream>
using std::cerr;
using std::cout;
using std::endl;
#include <fstream>
using std::ifstream;
#include <cstdlib> // for exit function
// This program reads values from the file 'example.dat'
// and echoes them to the display until a negative value
// is read.
int main()
{
ifstream indata; // indata is like cin
int num; // variable for input value
indata.open("ex ample.dat"); // opens the file
if(!indata) { // file couldn't be opened
cerr << "Error: file could not be opened" << endl;
exit(1);
}
indata >> num;
while ( !indata.eof() ) { // keep reading until end-of-file
cout << "The next number is " << num << endl;
indata >> num; // sets EOF flag if no value found
}
indata.close();
cout << "End-of-file reached.." << endl;
return 0;
}

best regards

It works fine on my Linux machine. Any specific problem?

[ssharish]

which distribution of linux are u using. the code looks to ok. and what compiler are u using

ssharish

[paultawk]

we i'm using the g++ compiler, and the problem is that it wasnt able to locate the headers such as iostream and ifstream. Any ideas?

[arne]

we i'm using the g++ compiler, and the problem is that it wasnt able to locate the headers such as iostream and ifstream. Any ideas?

Invoke 'g++ -v' to find out from where g++ tries to get its includes. In the output look for something like

--with-gxx-include-dir=/usr/include/c++/4.0.2

Go there and look if the headers are there or not.

[paultawk]

for compilation i used the following, is it wrong?

g++ -Wall -D__LINUX_OSS__ -o filename filename.cpp

[arne]

for compilation i used the following, is it wrong?

g++ -Wall -D__LINUX_OSS__ -o filename filename.cpp

Looks good to me. If you don't use/need it somewhere in your code, you can omit the -D __LINUX ... part. Or do you have any specific reason you use it?

Did you find your headers?