Segmentation Error in C while trying to input - c

Question

I am trying to make a C program to take in a list of movies and add to it with memory alloction and able to retrieve movies from the list as well using a txt file.
movies.txt
5
Mission Impossible
Action
4
2008
Up
Action
3
2012
I keep running into an error after running in the command line and when the menu comes up, whenever I input something it runs a seg fault. I don't have access to a debugger right now and I'm not exactly sure what's wrong although I assume its a problem with my pointers or memory alloc.
Can someone point me in the right direction?
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
// limit definition
#define LIMIT 999
//movie structure
struct movie
{
char name[100];
char type[30];
int rating;
int releaseDate;
};
//reads file
void readFile(FILE *fp,struct movie* movieList[],int *noOfReviews)
{
char buffer[100];
int counter = 0;
struct movie* newNode;
fgets(buffer,LIMIT,fp);
*noOfReviews = atoi(buffer); // number of reviews in buffer
printf("%d",*noOfReviews); //prints reviews
while((fgets(buffer,LIMIT,fp)!=NULL) || (*noOfReviews > 0)) //if null or reviews greater than zero
{
if(counter % 4 == 0)
{
struct movie* tmpNode = (struct movie*)malloc(sizeof(struct movie)); //allocates memory
movieList[counter] = tmpNode;
newNode = tmpNode;
*noOfReviews--; // --#ofreviews
}
//copys struc into buffer
switch(counter % 4 )
{
case 0:
strcpy(newNode->name,buffer);
break;
case 1:
strcpy(newNode->type,buffer);
break;
case 2:
newNode->rating = atoi(buffer);
break;
case 3:
newNode->releaseDate = atoi(buffer);
break;
default:
printf("Exception\n");
break;
}
counter++;
}
}
//searches list
int searchList(struct movie* movielist[],char movieName[],int noOfMovies)
{
int counter = 0;
while(noOfMovies--)
{
if(strcmp(movielist[counter]->name,movieName) == 0) // if string compares to name
{
return counter;
}
counter++;
}
return -1;
}
//compares strings of name
int nameStrCmp(const void *a, const void *b)
{
return (strcmp(((struct movie*)a)->name,((struct movie*)b)->name));
}
// compares rating strings
int ratingStrCmp(const void * a, const void * b)
{
return (((struct movie*)a)->rating - ((struct movie*)b)->rating);
}
//displays the structure
void display(struct movie* movieList[],int n)
{
int i;
struct movie* searchRslt;
for(i = 0; i < n; i++)
{
searchRslt = movieList[i];// search result index of movies list
//prints struct information
printf("name:%s\n type:%s\n rating:%d\n releaseDate:%d\n",searchRslt->name,searchRslt->type,searchRslt->rating,searchRslt->releaseDate);
}
}
//main function
int main(int argc, char *argv[])
{
char buffer[100];
int noOfReviews;
struct movie* movieList[1000];
struct movie *searchRslt;
char mName[100];
if(argc <= 1)
{
printf("invalid");
return 0;
}
FILE *fp = fopen(argv[1],"r");
readFile(fp,movieList,&noOfReviews);
while(1)
{
//case selection menu
int input;
printf("Enter 1 to search for a movie.\n");
printf("Enter 2 to display the list of movies by name.\n");
printf("Enter 3 to display the list of movies by rating.\n");
scanf("%d",&input);
switch(input)
{
case 1:
printf("Enter movie name to search:");
scanf("%s",mName);
int index = searchList(movieList,mName,noOfReviews);
if(index < 0)
printf("Not found!!\n"); // if movie not found
else // gets movies
{
searchRslt = movieList[index];
printf("name:%s\n type:%s\n rating:%d\n releaseDate:%d\n",searchRslt->name,searchRslt->type,searchRslt->rating,searchRslt->releaseDate);
}
break;
case 2:
qsort(movieList,noOfReviews,sizeof(struct movie),nameStrCmp);
display(movieList,noOfReviews);
break;
case 3:
qsort(movieList,noOfReviews,sizeof(struct movie),ratingStrCmp);
display(movieList,noOfReviews);
break;
default:
break;
}
}
}

Answer 1

A few formatting/readability/coding suggestions: (Some are just suggestions, others actually eliminate warnings.)
format. (mainly indention)
replace 'struct movie' with MOVIE everywhere. (see struct definition below)
initialize variables before use.
pay attention to buffer size in declaration and usage (fgets errors)
Compile with warnings on. (eg, with gcc use -Wall)
The following is limited to addressing each of these items, including new struct definition. The following compiles and builds without warnings or errors. It does not include debugging your code. (If can do a Beyond Compare (its free), between your original post and the edited version below, you can easily find where the edits are.)
(At the time of this post, there was no information provided about your input file, so further efforts were not made.)
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
// limit definition
#define LIMIT 999
//movie structure
typedef struct {
char name[100];
char type[30];
int rating;
int releaseDate;
}MOVIE;
//reads file
void readFile(FILE *fp,MOVIE* movieList[],int *noOfReviews)
{
char buffer[LIMIT];
int counter = 0;
MOVIE* newNode = {0};
fgets(buffer,LIMIT,fp);
*noOfReviews = atoi(buffer); // number of reviews in buffer
printf("%d",*noOfReviews); //prints reviews
while((fgets(buffer,LIMIT,fp)!=NULL) || (*noOfReviews > 0)) //if null or reviews greater than zero
{
if(counter % 4 == 0)
{
MOVIE* tmpNode = (MOVIE *)malloc(sizeof(MOVIE)); //allocates memory
movieList[counter] = tmpNode;
newNode = tmpNode;
*noOfReviews--; // --#ofreviews
}
//copys struc into buffer
switch(counter % 4 ) {
case 0:
strcpy(newNode->name,buffer);
break;
case 1:
strcpy(newNode->type,buffer);
break;
case 2:
newNode->rating = atoi(buffer);
break;
case 3:
newNode->releaseDate = atoi(buffer);
break;
default:
printf("Exception\n");
break;
}
counter++;
}
}
//searches list
int searchList(MOVIE* movielist[],char movieName[],int noOfMovies)
{
int counter = 0;
while(noOfMovies--)
{
if(strcmp(movielist[counter]->name,movieName) == 0) // if string compares to name
{
return counter;
}
counter++;
}
return -1;
}
//compares strings of name
int nameStrCmp(const void *a, const void *b)
{
return (strcmp(((MOVIE*)a)->name,((MOVIE*)b)->name));
}
// compares rating strings
int ratingStrCmp(const void * a, const void * b)
{
return (((MOVIE*)a)->rating - ((MOVIE*)b)->rating);
}
//displays the structure
void display(MOVIE* movieList[],int n)
{
int i;
MOVIE* searchRslt;
for(i = 0; i < n; i++)
{
searchRslt = movieList[i];// search result index of movies list
//prints struct information
printf("name:%s\n type:%s\n rating:%d\n releaseDate:%d\n",searchRslt->name,searchRslt->type,searchRslt->rating,searchRslt->releaseDate);
}
}
//main function
int main(int argc, char *argv[])
{
int noOfReviews;
MOVIE* movieList[1000];
MOVIE *searchRslt;
char mName[100];
if(argc <= 1)
{
printf("invalid");
return 0;
}
FILE *fp = fopen(argv[1],"r");
readFile(fp,movieList,&noOfReviews);
while(1)
{
//case selection menu
int input;
printf("Enter 1 to search for a movie.\n");
printf("Enter 2 to display the list of movies by name.\n");
printf("Enter 3 to display the list of movies by rating.\n");
scanf("%d",&input);
switch(input)
{
case 1:
printf("Enter movie name to search:");
scanf("%s",mName);
int index = searchList(movieList,mName,noOfReviews);
if(index < 0)
printf("Not found!!\n"); // if movie not found
else // gets movies
{
searchRslt = movieList[index];
printf("name:%s\n type:%s\n rating:%d\n releaseDate:%d\n",searchRslt->name,searchRslt->type,searchRslt->rating,searchRslt->releaseDate);
}
break;
case 2:
qsort(movieList,noOfReviews,sizeof(MOVIE),nameStrCmp);
display(movieList,noOfReviews);
break;
case 3:
qsort(movieList,noOfReviews,sizeof(MOVIE),ratingStrCmp);
display(movieList,noOfReviews);
break;
default:
break;
}
}
}