Thread: using fstream operator >>

I have a file, which does open, that contains...

Code:

Include="C:\GCC"
LibLink=mystds
LibLink=comctl32
LibLink=mystdspp
LibLink=gdi32

I would like to read the entire file contents into a string, but when I use the >> operator like so...

Code:

CFG >> Configuration; //CFG is the ifstream and Configuration is a C++ style string.

...and output the string Configuration to cout, I get this...

Code:

cout << "Configuration = (" << Configuration << ")" << endl;

Code:

Configuration = (0x22fe00)

Am I misusing the operator?

Yup. The >> operator reads tokens. Use getline() (in <string>) to get full lines. Not sure what to do if you want the entire file in a single string, in any case, you are probably better off processing line by line.

even so, you should still be getting the entire first line... I suspect there's something else wrong with your code, but you're going to have to post it for us to see...

Alright. That's simple enough. Do ifstreams have a length member, or should I use some tells and seeks?

Oh, and here's my code.

Code:

#include <cstdlib>
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>

using namespace std;

int main(int argc, char *argv[])
 {
  if(argc == 1)
    return EXIT_SUCCESS;
  else if(argc == 2)
   {
    string GCC = "C:\\GCC\\bin\\gcc ";
    string GPP = "C:\\GCC\\bin\\g++ ";
    string Includes = "-I\"C:\\GCC\\include\" ";
    string CPPIncludes = "-I\"C:\\GCC\\include\\c++\\3.4.2\" -I\"C:\\GCC\\include\\c++\\3.4.2\\mingw32\" -I\"C:\\GCC\\include\\c++\\3.4.2\\backward\" -I\"C:\\GCC\\lib\\gcc\\mingw32\\3.4.2\\include\" ";
    string Libraries = "-L\"C:\\GCC\\lib\" ";
    string CustomIncludes;
    string CustomLibraries;
    string CustomLibLinks;
    string inFile = argv[1];
    string inName = "\"" + inFile + "\" ";
    string inType;
    string outName = "\"";
    string arguments;

    ifstream CFG("rungcc.cfg");
    if(!CFG.is_open())
      cout << "Failed to open rungcc.cfg." << endl;
    stringstream CFGString;
    string ConfigLine;
    CFGString << CFG;
    CFGString >> Configuration;
    cout << "CFG = (" << CFG << ")" << endl;
    cout << "CFGString = (" << CFGString << ")" << endl;
    cout << "Configuration = (" << Configuration << ")" << endl;
    CFG.close();
    for(int index = Configuration.find("Include=", 0); index != string::npos; index = Configuration.find("Include=", index))
     {
      index += 7;
      CustomIncludes += "-I\"";
      for(; Configuration[index] != '\n'; ++index)
        CustomIncludes += Configuration[index];
      CustomIncludes += "\" ";
     }
    for(int index = Configuration.find("Library=", 0); index != string::npos; index = Configuration.find("Include=", index))
     {
      index += 7;
      CustomLibraries += "-L\"";
      for(; Configuration[index] != '\n'; ++index)
        CustomLibraries += Configuration[index];
      CustomLibraries += "\" ";
     }
    for(int index = Configuration.find("LibLink=", 0); index != string::npos; index = Configuration.find("Include=", index))
     {
      index += 4;
      CustomLibLinks += "-l\"";
      for(; Configuration[index] != '\n'; ++index)
        CustomLibLinks += Configuration[index];
      CustomLibLinks += "\" ";
     }

    int NameLength = strlen(inFile.c_str());
    int index;
    for(index = NameLength; index >= 0; --index)
      if(inFile[index] == '\\')
        break;
    for(++index; index < NameLength; ++index)
      if(inFile[index] != '.')
        outName += inFile[index];
      else
        break;
    outName += ".exe\" ";

    for(++index; index < NameLength; ++index)
      inType += inFile[index];

    if(inType == "c")
      arguments = GCC + Includes + Libraries + inName + "-o " + outName;
    else if(inType == "cpp" || inType == "cc" || inType == "cp" || inType == "cxx" || inType == "c++")
      arguments = GPP + Includes + CPPIncludes + Libraries + inName + "-o " + outName;

    cout << "CustomIncludes = (" << CustomIncludes << ")" << endl;
    cout << "CustomLibraries = (" << CustomLibraries << ")" << endl;
    cout << "CustomLibLinks = (" << CustomLibLinks << ")" << endl;

//    system(arguments.c_str());
   }
  return EXIT_SUCCESS;
 }

Oh, my mistake. I was in the middle of changing Configuration to ConfigLine. And ignore all the CFGString stuff. That was just desperation on my part. Use this...

Code:

ifstream CFG("rungcc.cfg");
if(!CFG.is_open())
  cout << "Failed to open rungcc.cfg." << endl;
string Configuration;
CFG >> Configuration;

That's what I had.

Hmm.....Well, that gives the first line of the file. But when I copy that into the rest of the code, I get nothing, literally. The output is Configuration = (). I'm including all those headers, using namespace std, everything.

Bah, I found it. I just needed to specify the full file name. rungcc.cfg was in the the same folder as the program, but not the folder I was using the command line in. Thanks for helping.