I've been working on this for the last few hours and I cannot seem to find why it isn't working, the printf in the store_car_stats function prints weird stuff from my argv and it runs through on gdb but seg faults normally. its really weird and I cannot seem to find the problem.
the input file it requires is
3
1993 Chevy Blazer 100200
2007 Honda Civic 23787
1903 Ford ModelT 90000
the update file is
4
1993 Chevy Blazer 39
1903 Ford ModelT 20
1993 Chevy Blazer 2
2014 Jeep Patriot 100
my code
#include <stdio.h>
#include <stdlib.h>
#define STRLEN 20
typedef struct automobiles{
int year;
char* make;
char* model;
int miles;
}Car;
void fill_garage(Car** carage,int*size,char* inputFile);
int equals(Car* garage,int year,char* make,char* model);
void drive_cars(Car* garage,int* num_cars,char* driving_records);
void store_car_stats(Car* garage,int num_cars,char* outFile);
void empty_garage(Car* garage,int num_cars);
int main(int argc,char* argv[]){
if(argc!=4){
printf("Invalid number of arguments, You have %d",argc);
return 0;
}
int size;
int newsize;
Car* mywhips;
fill_garage(&mywhips,&size,argv[1]);
printf("\n ))) %d %s %s %d",mywhips[1].year,mywhips[1].make,mywhips[1].model,mywhips[1].miles);
drive_cars(mywhips,&newsize,argv[2]);
store_car_stats(mywhips,newsize,argv[3]);
empty_garage(mywhips,newsize);
return 0;
}
void fill_garage(Car** warehouse,int*size,char*inputFile){
FILE* file=fopen(inputFile,"r");
int i;
Car* garage;
fscanf(file,"%d",size); //get size and place in address
if(file==NULL){//did file open correctly?
printf("File returned NULL when attempting to read..try again");
}
garage=malloc(sizeof(Car)*(*size)); //reserve memory for the file input
warehouse = &garage;
printf("input File DATA \n");
for(i=0;i<*size;i++){
garage[i].make = malloc(sizeof(char)*STRLEN); //reserve memory for the make
garage[i].model = malloc(sizeof(char)*STRLEN); //and model
//scan input and place in struct
fscanf(file,"%d %s %s %d",&garage[i].year,garage[i].make,garage[i].model,&garage[i].miles); //seg fault here
printf("\nYear: %d \nMake: %s\nModel: %s\nMiles: %d\n",garage[i].year,garage[i].make,garage[i].model,garage[i].miles); //seg fault here
}
fclose(file);
//printf("here");
return;
}
int equals(Car* car,int year,char* make,char* model){
if(year == car->year){
if(make == car->make){
if(model == car->model){
return 1;
}
}
}
return 0;
}
void drive_cars(Car* garage,int* num_cars,char* driving_records){
FILE* file=fopen(driving_records,"r");
int year,miles,i;
char* make;
char* model;
if(file == NULL){
printf("update file opened NULL");
}
fscanf(file,"%d",num_cars);
for(i=0;i<*num_cars;i++){
make = malloc(sizeof(char)*(*num_cars));
model = malloc(sizeof(char)*(*num_cars));
fscanf(file,"%d%s%s%d",&year,make,model,&miles);
printf("\nYear: %d \nMake: %sModel: %s\nMiles: %d\n",year,make,model,miles);
if(equals(&(garage[i]),year,make,model)==1){
printf("here");
garage[i].miles+=miles;
}
}
//printf("here");
free(make);
free(model);
}
void store_car_stats(Car* garage, int num_cars,char* outFile){
FILE* file=fopen(outFile,"w");
//printf("store_car_stats\n");
if(file == NULL){
printf("ouptput file returned NULL");
return;
}
int i;
printf("%d",num_cars);
for(i=0;i<num_cars;i++){
printf("\nYour %d %s %s has now driven %d", garage[i].year, garage[i].make, garage[i].model, garage[i].miles);
fprintf(file,"\n\n\nA %d %s %s that has now driven %d",garage[i].year,garage[i].make,garage[i].model,garage[i].miles);
}
fclose(file);
}
void empty_garage(Car* garage, int num_cars){
int i;
for(i=0;i<num_cars;i++){
//free(garage[i].make);
//free(garage[i].model);
}
//free(garage);
}
In fill_garage
, this is an issue:
warehouse = &garage;
The garage
is a local variable, and you're assinging the address of a local variable to warehouse
. This is wrong, regardless of the rest of the code in the function. When the function returns, that garage
variable ceases to exist, so the &garage
will be pointing to who-knows-what.
You probably meant to do this:
*warehouse = garage;
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