Segmentation Fault Error (C) - c

Question

I am currently writing a program that is supposed to receive input from a text file and output statistics about the text such as the number of letters, size of words and how often they occur, and how many times each word occurs. However, every time I run the program, I get a segmentation fault error. The program runs until I hit the line Letter Count Analysis. The I receive the segmentation fault error. Here is some sample text:
1
Hello my name is Bob
I live in Canada
The number represents how many lines are supposed to be read. What should I do to correct my issue? I am very new to programming so I'm sure it is something basic.
#include <stdio.h>
#include <string.h>
#define MAX_LINE_LENGTH 80
#define MAX_WORD_LENGTH 20
#define MAX_LINES 10
void letterAnalysis(char [][MAX_LINE_LENGTH], int lineTotal);
int wordLengthAnalysis(char [][MAX_LINE_LENGTH], int lineTotal, int wordLength);
void wordAnalysis(char [][MAX_LINE_LENGTH], int lineTotal);
int main (void){
int lineTotal, wordSize;
char text[lineTotal][MAX_LINE_LENGTH];
char n[1];
fgets(n, 10, stdin);
lineTotal = n[0] - '0';
for(int i = 0; i < lineTotal; i++){
fgets(text[i], MAX_WORD_LENGTH, stdin);
}
printf("\n***Letter count analysis***\n");
letterAnalysis(text, lineTotal);
printf("\n***Word length analysis***\n");
for (int i = 1; i <= MAX_WORD_LENGTH; i++){
wordSize = wordLengthAnalysis(text, lineTotal, i);
if (wordSize == 1){
printf("\n%-2d\tword of length %d", wordSize, i);
}
else{
printf("\n%-2d\twords of length %d", wordSize, i);
}
}
printf("\n\n***Word analysis***\n");
wordAnalysis(text, lineTotal);
return 0;
}
void letterAnalysis(char text[][MAX_LINE_LENGTH], int lineTotal){
int alphabet[26] = {0};
for (int i = 0; i < lineTotal; i++){
for(int j = 0; j < MAX_LINE_LENGTH; j++){
switch(text[i][j]){
case 'A': case 'a':
alphabet[0]++;
break;
case 'B': case 'b':
alphabet[1]++;
break;
case 'C': case 'c':
break;
alphabet[2]++;
case 'D': case 'd':
alphabet[3]++;
break;
case 'E': case 'e':
alphabet[4]++;
break;
case 'F': case 'f':
alphabet[5]++;
break;
case 'G': case 'g':
alphabet[6]++;
break;
case 'H': case 'h':
alphabet[7]++;
break;
case 'I': case 'i':
alphabet[8]++;
break;
case 'J': case 'j':
alphabet[9]++;
break;
case 'K': case 'k':
alphabet[10]++;
break;
case 'L': case 'l':
alphabet[11]++;
break;
case 'M': case 'm':
alphabet[12]++;
break;
case 'N': case 'n':
alphabet[13]++;
break;
case 'O': case 'o':
alphabet[14]++;
break;
case 'P': case 'p':
alphabet[15]++;
break;
case 'Q': case 'q':
alphabet[16]++;
break;
case 'R': case 'r':
alphabet[17]++;
break;
case 'S': case 's':
alphabet[18]++;
break;
case 'T': case 't':
alphabet[19]++;
break;
case 'U': case 'u':
alphabet[20]++;
break;
case 'V': case 'v':
alphabet[21]++;
break;
case 'W': case 'w':
alphabet[22]++;
break;
case 'X': case 'x':
alphabet[23]++;
break;
case 'Y': case 'y':
alphabet[24]++;
break;
case 'Z': case 'z':
alphabet[25]++;
break;
}
}
}
for(int i = 0; i <= 25; i++){
printf("%c: \t%d\n",'a' + i, alphabet[i]);;
}
}
int wordLengthAnalysis(char text[][MAX_LINE_LENGTH], int lineTotal, int wordLength){
int sentenceLength;
int counter, wordSize = 0;
for(int i = 0; i < lineTotal; i++){
sentenceLength = strlen(&text[i][0]);
for(int j = 0; j < sentenceLength + 2; j++){
if(text[i][j] == ' '){
if(counter == wordLength){
++wordSize;
counter = 0;
}
else{
counter = 0;
}
}
else{
counter++;
}
}
}
return wordSize;
}
void wordAnalysis(char text[][MAX_LINE_LENGTH], int lineTotal){
char maxWords[800];
char word[MAX_LINE_LENGTH], word2[MAX_WORD_LENGTH], *ptrText, *ptrTextCounter;
int counter, textCounter = 0;
int sentenceLength, wordTracker;
int lineFlag;
for(int i = 0; i < lineTotal; i++){
ptrText = &text[i][0];
sentenceLength = strlen(ptrText);
counter = 0;
for (int j = 0; j < sentenceLength + 1; j++){
wordTracker = 1;
if (text[i][j] == ' ' ){
if (counter != 0){
sprintf(word, "%.*s", counter, ptrText);
ptrTextCounter = &text[i][j+1];
lineFlag = j;
if(strstr(maxWords, word) == NULL){
for (int k = i; k < lineTotal; k++){
textCounter = 0;
if (lineFlag == j){
ptrTextCounter = &text[i][j+1];
}
else{
lineFlag = 0;
ptrTextCounter = &text[i][j+1];
}
for ( ; lineFlag < sentenceLength; lineFlag++){
if(text[k][lineFlag] == ' '){
if (textCounter != 0){
if(textCounter == counter){
sprintf(word2, "%.*s", textCounter, ptrTextCounter);
if(strcmp(word, word2) == 0){
wordTracker++;
}
}
ptrTextCounter = &text[k][lineFlag];
textCounter = 0;
}
else{
ptrTextCounter = &text[k][lineFlag+1];
}
}
else{
textCounter++;
}
}
}
if(wordTracker == 1){
printf("\n\"%.*s\"\t\tappeared %d time", counter, ptrText, wordTracker);
}
else{
printf("\n\"%.*s\"\t\tappeared %d time", counter, ptrText, wordTracker);
}
}
strcat(maxWords, word);
ptrText = &text[i][j+1];
counter = 0;
}
else{
ptrText = &text[i][j+1];
}
}
else{
counter++;
}
}
}
}

Answer 1

I get a couple of warnings:
main.c:17:14: warning: variable length array used [-Wvla]
char text[lineTotal][MAX_LINE_LENGTH];
^
main.c:17:15: warning: variable 'lineTotal' is uninitialized when used here [-Wuninitialized]
char text[lineTotal][MAX_LINE_LENGTH];
^~~~~~~~~
You haven't initialized lineTotal but are using it. This causes undefined behavior.
main.c:64:21: warning: code will never be executed [-Wunreachable-code]
alphabet[2]++;
^~~~~~~~
Your break; is likely misplaced.
main.c:152:20: warning: variable 'counter' may be uninitialized when used here [-Wconditional-uninitialized]
if(counter == wordLength){
^~~~~~~
Again, you're using a potentially uninitialized variable.
Also:
char n[1];
fgets(n, 10, stdin);
Your array has one element but you tell fgets it can access up to n[10].
Hint (if it wasn't obvious already): never program C without warnings.