C: Linked list word frequency - Standard input - c

Question

Edit: Fixed duplication error in code.
I attempted to create a word frequency analysis program that reads in from standard input.
I have two questions.
Currently I am using '\n' to indicate when my program should stop reading in input, I need it to read until the user is done typing. Would it be better to use EOF or the null terminator '\0'
This may be a dumb question but I cannot figure out what is wrong with my output it doubles the letters up every time.
Example input: "This is a test test of the program for frequency is a this for for"
Output:
thhiiss 1
iiss 2
aa 2
tteesstt 2
ooff 1
tthhee 1
pprrooggrraamm 1
ffoorr 3
ffrreeqquueennccyy 1
tthhiiss 1
As you can see the count close to correct for each word, but cannot figure out why the letters are duplicating.
Here is the code I have used:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "list.h"
#define MAXWORD 100
//===========================================================================
struct lnode {
struct lnode *next;
struct lnode *counter;
struct lnode *pLast;
struct lnode *prev;
struct lnode *head;
char *word;
int line;
int count;
int freq;
};
struct lnode *start = NULL;
//===========================================================================
struct lnode *createWordCounter(char *str)
{
struct lnode *pCounter = NULL;
pCounter = (struct lnode*)malloc(sizeof(struct lnode));
pCounter->word = (char*)malloc(strlen(str)+1);
strcpy(pCounter->word, str);
pCounter->freq = 1;
pCounter->next = NULL;
return pCounter;
}
//===========================================================================
void addWord(char *str)
{
struct lnode *pCounter = NULL;
struct lnode *pLast = NULL;
if(start == NULL)
{
start = createWordCounter(str);
return;
}
// If the word is in the list, increment its count
pCounter = start;
int temp = pCounter->freq;
while(pCounter != NULL)
{
if(strcmp(str, pCounter->word) == 0)
{
pCounter->freq++;
return;
}
pLast = pCounter;
pCounter = pCounter->next;
}
// Word is not in the list, add it
pLast->next = createWordCounter(str);
}
//===========================================================================
int getNextWord(char *buf, int bufsize) {
char *p = buf;
char ch;
do {
ch = getchar();
if (ch == '\n')
return 0;
} while (!((ch >= 'A' && ch <= 'Z')||( ch >= 'a' && ch <= 'z')));
do {
if (p - buf < bufsize - 1){
if( ch >= 97 && ch <= 122)//making the ch lowercase if needed
*p++ = ch;
else{ch += 32;
*p++ = ch;}
}//End of if
ch = getchar();
} while (((ch >= 'A' && ch <= 'Z')||( ch >= 'a' && ch <= 'z')));
*p = '\0';
return 1;
}
//===========================================================================
void show(struct lnode *pWord)
{
printf("%s %i\n", pWord->word, pWord->freq);
}
//===========================================================================
int main(){
struct lnode *counter = NULL;
int size = 1000;
char buf[MAXWORD];
while(getNextWord(buf, size) != 0 ){
addWord(buf);
}
counter = start;
while(counter != NULL)
{
show(counter);
counter = counter->next;
}
counter = start;
while(counter != NULL)
{
free(counter->word);
start = counter;
counter = counter->next;
free(start);
}
return 0;
}
This is my first time posting so please let me know if I did anything wrong. Any help is appreciated.
Thanks.

Answer 1

Look at this carefully, it is assigning ch twice to *p
if( ch >= 97 && ch <= 122)//making the ch lowercase if needed
*p++ = ch;
else{ch += 32;}
*p++ = ch;
I think the trailing "}" on the else statement is misplaced.
if( ch >= 97 && ch <= 122) { //making the ch lowercase if needed
*p++ = ch;
} else {
ch += 32;
*p++ = ch;
}
Also, your code will be greatly more readable if you learn about the functions
isalpha, islower, isupper, tolower, toupper. man ctype for info.

Answer 2

Would it be better to use EOF or the null terminator '\0' ?
Use EOF because if you press ctl+D getchar() consider input as EOF . You can also use \n or Use an OR logic with \n,EOF
what is wrong with my output it doubles the letters up every time ?
See this below code in function getNextWord()
if( ch >= 97 && ch <= 122)//making the ch lowercase if needed
*p++ = ch;
//this checks if input character is lowercase character, then store it into buffer
else{ch += 32;} // if input character is lowercase character, won't execute else part
*p++ = ch;
// now again you are copying same input character into buffer next location
Modify above part.