pigLatin.c

/*
	Pig Latin Translator 0.8.2
	User Enters a word after the prompt
	and gets the "Pig Latin" version back at the
	prompt.
	
	Example Compilation and Run
	Apoh:Documents apoh$ cc pigLatinTranslator.c -o pigLatin
	Apoh:Documents apoh$ ./pigLatin
	Please enter a word.
	Tappas
	The String You Entered: Tappas
	Your word in Pig Latin is APPASTAY
 
	Continue?  Press 'y':
	
	
	Author: EST Group CS380
*/

#include <stdio.h>
#include <string.h>
#include <regex.h> 

char pigLatin ( char *word )
{
	// First, get a count of the number
	// of characters in the user-input string
	int n;
	int charCount = 0;
	char *ayEnding = "AY";
	char *yayEnding = "YAY";
	
	for( n=0; word[n]; ++n)
	{
    		if( word[n] != ' ' )
		{
        		charCount ++;
    		}
	}

	// Create a substring with the first character of
	// the user-entered word.  This is then used as a test
	// for a consonant or vowel beginning word.
	char wordFirstChar[2];
	memcpy ( wordFirstChar, &word[0], 1 );
	wordFirstChar[1] = '\0';
	
	if (wordFirstChar[0]=='A' || wordFirstChar[0]=='E' || wordFirstChar[0]=='I' 
			|| wordFirstChar[0]=='O' || wordFirstChar[0]=='U' )
	{
		// If first letter is a vowel, just add 'yay'
		char pigLatinVowel[charCount+2];
		strcpy(pigLatinVowel, word);
		strcat(pigLatinVowel, yayEnding);
		pigLatinVowel[charCount+3] = '\0';
		
		printf("\nYour Word in Pig Latin is %s\n", pigLatinVowel);
	}	
	else
	{
		// If the word doesn't begin with a vowel, append
		// the first letter with 'ay'
		
		/* Declare a substring with the number of characters
		   from the string.  This will be your base to which
	       the first character of the original string and
	       'ay' will be appended */
		char subString[charCount];
		memcpy( subString, &word[1], charCount-1 );
		subString[charCount-1] = '\0'; // must ensure null terminator is re-added
	
		// You have the char, you have the substring, concatenate
		// the two and append 'ay'
		char pigLatinConsonant[charCount+2];
		strcpy(pigLatinConsonant, subString);

		strcat(pigLatinConsonant, wordFirstChar);
		strcat(pigLatinConsonant, ayEnding); 
		pigLatinConsonant[charCount+3] = '\0';

		printf("\nYour word in Pig Latin is %s\n", pigLatinConsonant);
	}
}

// Helper method to change the string to all caps
void upCaseStr(char *s)
{
  char  *p;

  for (p = s; *p != '\0'; p++) 
    *p = (char) toupper(*p);
}

int main (void)
{
	/*  Prototype declaration for pigLatin function
    	This tells the compiler that pigLatin returns a char
        and takes and array of 50 chars.  Not really necessary
        since pigLatin is declared before main, but playing
        it safe */
    char pigLatin (char *string);
	char string[256]; // The user entered word
	char choice = 'y';	
	
	// Regular expression begins with any upper or lower
	// and only contains them as well.   String is arbitrarily 
	// long.
	regex_t reg;
	const char *regex="^[A-z]+$";
	regmatch_t matches[256];
	regcomp(&reg, regex, REG_EXTENDED); // Must compile the regex before use
    
    while (choice=='y')
    {
		printf ("Please enter a word.\n");
		scanf ( "%s" , string );
		
		// Start with ensuring first character of the user string is A-Z or a-z by comparing
		// to the ASCII value for those letters.
		if ( ( string[0] > 64 && string[0] < 91 ) || ( string[0] > 96 && string[0] < 123 ) )
		{	
			// Now check to ensure the entire word is a contiguous string of characters
			if(regexec(&reg, string, 256, matches, 0) == 0)
        	{
                printf ("\nThe String You Entered: %s", string );
				upCaseStr(string);
				pigLatin (string);
				printf (" \nContinue?  Type 'y' followed by enter to continue or any other character to end: ");
				scanf(" %c", &choice);
        	}
        	else
        	{
                printf("\nYour word must contain only letters\n");
                choice = 'y';
			}		
		}
		else
		{
			printf ("\nYour word doesn't have a valid starting character.\n\n");
			choice = 'y';
		}
	}

	return 0;
}