kishio.cpp

Code

/*
    kishio.cpp
    CIS 250
    Dave Klick
    2014-01-22
    
    This is the implementation file for a set of utility
    functions to do input with validation.

    Updated 2014-02-11 to add:
        char getChar(const char*, const char*)
*/

#include "kishio.h"

namespace kishio {
    /*
        char getChar(const char* prompt, const char* allowed);

        Arguments:
            prompt: prompt to display to user
            allowed: set of allowed characters for input

        Returns: a valid char entered by the user

        This function prompts the user and gets a char from
        the keyboard. If the value entered is not a valid char or
        is outside the allowed set specified, this function
        will discard it and re-prompt the user.
    */
    char getChar(const char* prompt, const char* allowed) {
        char buf[200];
        const char* ptr;
        bool valid = false;

        while (!valid) {
            cout << prompt;
            cin.getline(buf, 200, '\n');
            if (strlen(buf) != 1) {
                cout << "Error: Must be one of: " << allowed << '\n';
            } else {
                ptr = strchr(allowed, (int) buf[0]);
                if (ptr == NULL) {
                    cout << "Error: Invalid char\n";
                } else {
                    valid = true;
                }
            }
        }
        return buf[0];
    }

    /*
        double getDouble(const char* prompt, const double min, const double max);
      
        Arguments:
            prompt: prompt to display to user
            min: the minimum value a user is allowed to enter
            max: the maximum value a user is allowed to enter
                
        Returns: a valid double entered by the user
   
        This function prompts the user and gets a double from
        the keyboard. If the value entered is not a valid double or
        is outside the range specified by min and max, this function
        will discard it and re-prompt the user.
    */
    double getDouble(const char* prompt, const double min, const double max) {
        double value = 0.0;
        char buf[200];
        char *endptr;
        bool valid = false;
        double dmin = min;
        double dmax = max;
        
        // swap min and max if they are reversed
        if (min > max) {
            dmin = max;
            dmax = min;
        }
        
        while (!valid) {
            cout << prompt;
            cin.getline(buf, 200, '\n');
            value = strtod(buf, &endptr);
            if (strlen(buf) == 0 || (unsigned) (endptr-buf) < strlen(buf)) {
                cout << "Error: Invalid number\n";
            } else {
                if (value < dmin) {
                    cout << "Error: below minimum value ("
                         << dmin << ")\n";
                } else if (value > dmax) {
                    cout << "Error: above maximum value ("
                         << dmax << ")\n";
                } else {
                    valid = true;
                }

            }
        }
        return value;
    }

    /*
        double getDouble(const double min, const double max);
      
        Arguments:
            min: the minimum value a user is allowed to enter
            max: the maximum value a user is allowed to enter
                
        Returns: a valid double entered by the user
   
        This function gets a double from the keyboard. If the
        value entered is not a valid double or is outside the
        range specified by min and max, this function will
        discard it and get another double from the user.
    */
    double getDouble(const double min, const double max) {
        return getDouble("", min, max);
    }

    /*
        double getDouble(const char* prompt);
      
        Arguments:
            prompt: prompt to display to user
                
        Returns: a valid double entered by the user
   
        This function prompts the user and gets a double from
        the keyboard. If the value entered is not a valid double 
        this function will discard it and get another double 
        from the user.
    */
    double getDouble(const char* prompt) {
        return getDouble(prompt, -DBL_MAX, DBL_MAX);
    }

    /*
        double getDouble();
      
        Arguments: none
                
        Returns: a valid double entered by the user
   
        This function gets a double from the keyboard. If the
        value entered is not a valid double this function will
        discard it and get another double from the user.
    */
    double getDouble() {
        return getDouble("", -DBL_MAX, DBL_MAX);
    }

    /*
        long getLong(const char* prompt, const long min, const long max);
      
        Arguments:
            prompt: prompt to display to user
            min: the minimum value a user is allowed to enter
            max: the maximum value a user is allowed to enter
                
        Returns: a valid long integer entered by the user
   
        This function prompts the user and gets a long integer from
        the keyboard. If the value entered is not a valid integer or
        is outside the range specified by min and max, this function
        will discard it and re-prompt the user.
    */
    long getLong(const char* prompt, const long min, const long max) {
        long value = 0L;
        char buf[200];
        char *endptr;
        bool valid = false;
        long lmin = min;
        long lmax = max;
        
        // swap min and max if they are reversed
        if (min > max) {
            lmin = max;
            lmax = min;
        }
        
        
        while (!valid) {
            cout << prompt;
            cin.getline(buf, 200, '\n');
            value = strtol(buf, &endptr, 10);
            if (strlen(buf) == 0 || (unsigned) (endptr-buf) < strlen(buf)) {
                cout << "Error: Invalid number\n";
            } else {
                if (value < lmin) {
                    cout << "Error: below minimum value ("
                         << lmin << ")\n";
                } else if (value > lmax) {
                    cout << "Error: above maximum value ("
                         << lmax << ")\n";
                } else {
                    valid = true;
                }

            }
        }
        return value;
    }

    /*
        long getLong(const long min, const long max);
      
        Arguments:
            min: the minimum value a user is allowed to enter
            max: the maximum value a user is allowed to enter
                
        Returns: a valid long integer entered by the user
   
        This function gets an integer from the keyboard. If the
        value entered is not a valid long integer or is outside the
        range specified by min and max, this function will
        discard it and get another integer from the user.
    */
    long getLong(const long min, const long max) {
        return getLong("", min, max);
    }

    /*
        long getLong(const char* prompt);
      
        Arguments:
            prompt: prompt to display to user
                
        Returns: a valid long integer entered by the user
   
        This function prompts the user and gets an integer from
        the keyboard. If the value entered is not a valid long integer 
        this function will discard it and get another integer 
        from the user.
    */
    long getLong(const char* prompt) {
        return getLong(prompt, LONG_MIN, LONG_MAX);
    }

    /*
        long getLong();
      
        Arguments: none
                
        Returns: a valid long integer entered by the user
   
        This function gets an integer from the keyboard. If the
        value entered is not a valid long integer this function will
        discard it and get another integer from the user.
    */
    long getLong() {
        return getLong("", LONG_MIN, LONG_MAX);
    }

    /*
        int getInt(const char* prompt, const int min, const int max);
      
        Arguments:
            prompt: prompt to display to user
            min: the minimum value a user is allowed to enter
            max: the maximum value a user is allowed to enter
                
        Returns: a valid integer entered by the user
   
        This function prompts the user and gets an integer from
        the keyboard. If the value entered is not a valid integer or
        is outside the range specified by min and max, this function
        will discard it and re-prompt the user.
    */
    int getInt(const char* prompt, const int min, const int max) {
        long value = 0L;
        char buf[200];
        char *endptr;
        bool valid = false;
        int imin = min;
        int imax = max;
        
        // swap min and max if they are reversed
        if (min > max) {
            imin = max;
            imax = min;
        }
        
        
        while (!valid) {
            cout << prompt;
            cin.getline(buf, 200, '\n');
            value = strtol(buf, &endptr, 10);
            if (strlen(buf) == 0 || (unsigned) (endptr-buf) < strlen(buf)) {
                cout << "Error: Invalid number\n";
            } else {
                if (value < imin) {
                    cout << "Error: below minimum value ("
                         << imin << ")\n";
                } else if (value > imax) {
                    cout << "Error: above maximum value ("
                         << imax << ")\n";
                } else {
                    valid = true;
                }

            }
        }
        return (int) value;
    }

    /*
        int getInt(const int min, const int max);
      
        Arguments:
            min: the minimum value a user is allowed to enter
            max: the maximum value a user is allowed to enter
                
        Returns: a valid integer entered by the user
   
        This function gets an integer from the keyboard. If the
        value entered is not a valid nteger or is outside the
        range specified by min and max, this function will
        discard it and get another integer from the user.
    */
    int getInt(const int min, const int max) {
        return getInt("", min, max);
    }

    /*
        int getInt(const char* prompt);
      
        Arguments:
            prompt: prompt to display to user
                
        Returns: a valid integer entered by the user
   
        This function prompts the user and gets an integer from
        the keyboard. If the value entered is not a valid integer 
        this function will discard it and get another integer 
        from the user.
    */
    int getInt(const char* prompt) {
        return getInt(prompt, INT_MIN, INT_MAX);
    }

    /*
        int getInt();
      
        Arguments: none
                
        Returns: a valid integer entered by the user
   
        This function gets an integer from the keyboard. If the
        value entered is not a valid integer this function will
        discard it and get another integer from the user.
    */
    int getInt() {
        return getInt("", INT_MIN, INT_MAX);
    }

}  // end of kishio namespace