Including header files in Xcode 4

Question

I'm going over the Stanford CS106B online course, and created a folder /usr/local where I put the header files for the course. However, whenever I call the header files I run into problems. Take this, for instance. When I try to compile it, I get the error , but RandomChance(double n) is a function in the header file random.h. Help!

Undefined symbols for architecture x86_64: "RandomChance(double)", referenced from: flipCoin() in main.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)

The program is below:

#include <iostream>
#include <string>
#include "/usr/local/random.h"

using namespace std;

string flipCoin();

string flipCoin() {
    if (RandomChance(0.50)) {
        return "heads";
    } else {
        return "tails";
    }
}

int main (int argc, const char * argv[])
{

    cout << "Enter number of votes" << endl;
    cout << "Enter percentage spread between candidates" << endl;
    cout << "Enter voting error percentage" << endl;
    return 0;
}

This is random.h

/*
 * Function: Randomize
 * Usage: Randomize();
 * -------------------
 * This function sets the random seed so that the random sequence
 * is unpredictable.   If this function is not called, the other 
 * functions will return the same values on each run. During the
 * debugging phase, it is best not to call this function, so that 
 * program behavior is repeatable.
 */
void Randomize();

/*
 * Function: RandomInteger
 * Usage: n = RandomInteger(low, high);
 * ------------------------------------
 * This function returns a random integer in the range low to high,
 * inclusive.
 */
int RandomInteger(int low, int high);

/*
 * Function: RandomReal
 * Usage: d = RandomReal(low, high);
 * ---------------------------------
 * This function returns a random real number in the half-open
 * interval [low .. high), meaning that the result is always
 * greater than or equal to low but strictly less than high.
 */
double RandomReal(double low, double high);

/*
 * Function: RandomChance
 * Usage: if (RandomChance(p)) . . .
 * ---------------------------------
 * The RandomChance function returns true with the probability
 * indicated by p, which should be a floating-point number between
 * 0 (meaning never) and 1 (meaning always).  For example, calling
 * RandomChance(.30) returns true 30 percent of the time.
 */
bool RandomChance(double p);

#endif /*RANDOM_H_*/

UPDATE: So it worked, and then I added another library by doing #include simpio.h and the whole thing went haywire. It showed 38 errors, including the following.

Ld /Users/alexandermoreno/Library/Developer/Xcode/DerivedData/voting-ccwjagcijcytcigfgxvxyiaplsxm/Build/Products/Debug/voting normal i386
    cd "/Users/alexandermoreno/Documents/Paradigms/assignment 1/voting"
    setenv MACOSX_DEPLOYMENT_TARGET 10.7
    /Developer/usr/bin/clang++ -arch i386 -isysroot /Developer/SDKs/MacOSX10.7.sdk -L/Users/alexandermoreno/Library/Developer/Xcode/DerivedData/voting-ccwjagcijcytcigfgxvxyiaplsxm/Build/Products/Debug -F/Users/alexandermoreno/Library/Developer/Xcode/DerivedData/voting-ccwjagcijcytcigfgxvxyiaplsxm/Build/Products/Debug -filelist /Users/alexandermoreno/Library/Developer/Xcode/DerivedData/voting-ccwjagcijcytcigfgxvxyiaplsxm/Build/Intermediates/voting.build/Debug/voting.build/Objects-normal/i386/voting.LinkFileList -mmacosx-version-min=10.7 -lcs106 -o /Users/alexandermoreno/Library/Developer/Xcode/DerivedData/voting-ccwjagcijcytcigfgxvxyiaplsxm/Build/Products/Debug/voting

Undefined symbols for architecture i386:
  "___CFConstantStringClassReference", referenced from:
      CFString in libcs106.a(mainwrapper.o)
      CFString in libcs106.a(mainwrapper.o)
      CFString in libcs106.a(mainwrapper.o)
      CFString in libcs106.a(mainwrapper.o)
      CFString in libcs106.a(mainwrapper.o)
      CFString in libcs106.a(mainwrapper.o)
      CFString in libcs106.a(mainwrapper.o)
      ...
  "_NSApp", referenced from:
      +[Glue showAbout:] in libcs106.a(mainwrapper.o)
      TerminateApp() in libcs106.a(mainwrapper.o)
      +[NSBundleWithoutSpuriousErrorLog aloadNibNamed:owner:] in libcs106.a(mainwrapper.o)
      _main in libcs106.a(mainwrapper.o)
      -[ConsoleTextView keyDown:] in libcs106.a(ConsoleTextView.o)
      +[Glue showAbout:] in libcs106.a(mainwrapper.o)
      TerminateApp() in libcs106.a(mainwrapper.o)
      +[NSBundleWithoutSpuriousErrorLog aloadNibNamed:owner:] in libcs106.a(mainwrapper.o)
      _main in libcs106.a(mainwrapper.o)
      -[ConsoleTextView keyDown:] in libcs106.a(ConsoleTextView.o)
  "_objc_msgSendSuper", referenced from:
      +[NSBundleWithoutSpuriousErrorLog aloadNibNamed:owner:] in libcs106.a(mainwrapper.o)
      -[ConsoleTextView initWithFrame:] in libcs106.a(ConsoleTextView.o)
      -[ConsoleTextView setFont:] in libcs106.a(ConsoleTextView.o)
      -[ConsoleTextView dealloc] in libcs106.a(ConsoleTextView.o)
      -[ConsoleTextView keyDown:] in libcs106.a(ConsoleTextView.o)
      -[ConsoleTextView rangeForUserTextChange] in libcs106.a(ConsoleTextView.o)
  "_CFBundleGetInfoDictionary", referenced from:
      _main in libcs106.a(mainwrapper.o)
  "_CFBundleCopyBundleURL", referenced from:
      _main in libcs106.a(mainwrapper.o)
  "_objc_msgSend", referenced from:
      +[Glue applicationDidFinishLaunching:] in libcs106.a(mainwrapper.o)
      +[Glue showAbout:] in libcs106.a(mainwrapper.o)
      CocoaConsoleResize(int, int, int, int) in libcs106.a(mainwrapper.o)
      TerminateApp() in libcs106.a(mainwrapper.o)
      SetConsoleSize(int, int, int, bool) in libcs106.a(mainwrapper.o)
      patched_read(void*, char*, int) in libcs106.a(mainwrapper.o)
      CreateMenuWithItems(NSString*, menuitem*, int) in libcs106.a(mainwrapper.o)
      ...
  "_CFURLCreateCopyDeletingLastPathComponent", referenced from:
      _main in libcs106.a(mainwrapper.o)
  "_CFURLGetFileSystemRepresentation", referenced from:
      _main in libcs106.a(mainwrapper.o)
  "_CFBundleGetMainBundle", referenced from:
      _main in libcs106.a(mainwrapper.o)
  "Main()", referenced from:
      +[Glue studentMain] in libcs106.a(mainwrapper.o)
  "_CFRelease", referenced from:
      _main in libcs106.a(mainwrapper.o)
  "_NSFileHandleDataAvailableNotification", referenced from:
      -[ConsoleTextView registerForNotifications] in libcs106.a(ConsoleTextView.o)
  "_NSForegroundColorAttributeName", referenced from:
      -[ConsoleTextView setFont:] in libcs106.a(ConsoleTextView.o)
  "_NSFontAttributeName", referenced from:
      -[ConsoleTextView setFont:] in libcs106.a(ConsoleTextView.o)
      +[ConsoleTextView contentSizeForPointSize:numRows:numCols:] in libcs106.a(ConsoleTextView.o)
  "_NSBeep", referenced from:
      -[ConsoleTextView keyDown:] in libcs106.a(ConsoleTextView.o)
  "_objc_msgSend_fpret", referenced from:
      +[ConsoleTextView contentSizeForPointSize:numRows:numCols:] in libcs106.a(ConsoleTextView.o)
  "_objc_msgSend_stret", referenced from:
      -[ConsoleTextView setPointSize:numRows:numCols:center:] in libcs106.a(ConsoleTextView.o)
      +[ConsoleTextView contentSizeForPointSize:numRows:numCols:] in libcs106.a(ConsoleTextView.o)
      +[ConsoleTextView createConsoleInWindow] in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSThread", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(mainwrapper.o)
  ".objc_class_name_NSAutoreleasePool", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(mainwrapper.o)
  ".objc_class_name_NSDictionary", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(mainwrapper.o)
  ".objc_class_name_NSString", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(mainwrapper.o)
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSMenu", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(mainwrapper.o)
  ".objc_class_name_NSMenuItem", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(mainwrapper.o)
  ".objc_class_name_NSBundle", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(mainwrapper.o)
      .objc_class_name_NSBundleWithoutSpuriousErrorLog in libcs106.a(mainwrapper.o)
     (maybe you meant: .objc_class_name_NSBundleWithoutSpuriousErrorLog)
  ".objc_class_name_NSApplication", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(mainwrapper.o)
  ".objc_class_name_NSObject", referenced from:
      .objc_class_name_Glue in libcs106.a(mainwrapper.o)
  ".objc_class_name_NSAttributedString", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSMutableDictionary", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSFont", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSScroller", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSScreen", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSWindow", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSScrollView", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSColor", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSNotificationCenter", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSFileHandle", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSData", referenced from:
      pointer-to-literal-objc-class-name in libcs106.a(ConsoleTextView.o)
  ".objc_class_name_NSTextView", referenced from:
      .objc_class_name_ConsoleTextView in libcs106.a(ConsoleTextView.o)
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

and this is the #simpio.h file

#ifndef SIMPIO_H_
#define SIMPIO_H_
/*
 * File: simpio.h
 * Version: 1.0CPP
 * Last modified on Wed Sep 18 13:34:29 PDT 2002 by jzelenski
 * ----------------------------------------------------------
 * This interface provides access to a simple package of
 * functions that simplify the reading of console input.
 */

#include "genlib.h"

/*
 * Function: GetInteger
 * Usage: n = GetInteger();
 * ------------------------
 * GetInteger reads a line of text from standard input and scans
 * it as an integer.  The integer value is returned.  If an
 * integer cannot be scanned or if more characters follow the
 * number, the user is given a chance to retry.
 */

int GetInteger();


/*
 * Function: GetLong
 * Usage: n = GetLong();
 * ---------------------
 * GetLong reads a line of text from standard input and scans
 * it into a long integer.  The long is returned.  If the 
 * number cannot be scanned or if extra characters follow it,
 * the user is given a chance to retry.
 */

long GetLong();

/*
 * Function: GetReal
 * Usage: x = GetReal();
 * ---------------------
 * GetReal reads a line of text from standard input and scans
 * it as a double.  If the number cannot be scanned or if extra
 * characters follow after the number ends, the user is given
 * a chance to reenter the value.
 */

double GetReal();


/*
 * Function: GetLine
 * Usage: s = GetLine();
 * ---------------------
 * GetLine reads a line of text from standard input and returns
 * the line as a string.  The newline character that terminates
 * the input is not stored as part of the string that is returned.
 */

string GetLine();

#endif /*SIMPIO_H_*/

Answer 1

Ok, so I saw that this got marked as a popular question. For anyone doing this, I would simply recommend looking up a later version of cs106b rather than the psets from SEE or iTunes, and downloading those and just waiting for the solutions to come out if you need them. A lot of the time, it will already be set up to work with the latest version of XCode. If not, it will be a bit of a mess setting up potentially. They also have some documentation describing what to do in the case of linker errors on most CS106b sites.

Answer 2

What's in the header? Is there an actual definition for the function or just a declaration?

Also, I suspect you want to put the file in /usr/local/include , I doubt /usr/local is in your header search path.

EDIT:

The library has the definition, the header has the declaration. Put the library in one of the searched library paths, chances are /usr/local/lib will do you proud.

EDIT #2:

In response to:

Hey, I did that and also used link binary with libraries to link the library. I then got this "ignoring file /Developer/SDKs/MacOSX10.7.sdk/usr/local/lib/libcs106.a, missing required architecture x86_64 in file." Could it be there is something wrong with the library for use in xcode 4? That's what another forum implied.

It would seem likely that the library is compiled for 32bit architecture and the project's architecture is set to 64bit. Changing the project setting to use 32bit should resolve the problem if a 64bit version of the library is not available.

EDIT #3: Looks as though that new library is for objective-c, or you're using a .m file extension and compiling as objective-c.