C - Read input from text file (int,string,int,int)

Question

First of all sorry for any english error. So, I have this data in a .txt file

Codigo,Produto,StockMinimo,StockAtual
1,Couro,300,1000
2,Tecido,250,2000
...

I want to skip the first line and read only the integers to a struct

I'm using the bellow function to count the line of the file:

int nrLinhasFicheiro(char *filename){
    char ch;
    FILE *file;
    file = fopen(filename, "r");
    int linhas = 0;
    if (file != NULL) {
         for (ch = getc(file); ch != EOF; ch = getc(file)) 
        if (ch == '\n')  
            linhas = linhas + 1; 
    }
    fclose(file);
    return linhas - 1;
}

and this one to read the file to the struct "Stock" :

void carregarStock(Stock *stock, char *nomeFicheiro){
    int i = 0;
    int codigo; //stores "codigo" values
    char stringFake[40], *storeProduto; //variables to store first line and "Produto" string
    int minimo, quantidade;
    
    FILE *fp = fopen(nomeFicheiro, "r");
    
    int numeroLinhas = nrLinhasFicheiro(nomeFicheiro);
    
    if (fp != NULL){
       
        if(numeroLinhas >0){
            fscanf(fp, "%s",stringFake);//skip first line
            
            while(i< numeroLinhas){
                fscanf(fp, "%d,%s ,%d,%d", &codigo, storeProduto, &minimo, &quantidade);
                //fscanf(fp, "%d,%s %d,%d", &codigo, storeProduto, &minimo, &quantidade);  also tried this and don't work
                
                if(codigo==1){
                    stock->minStockCouro = minimo;
                    stock->couroStock = quantidade;
                }else if(codigo==2){
                    stock->minStockTecido = minimo;
                    stock->tecidoStock = quantidade;
                }else if(codigo==3){
                    stock->minStockBorracha = minimo;
                    stock->borrachaStock = quantidade;
                }else if(codigo==4){
                    stock->minStockCordoes = minimo;
                    stock->cordoesStock = quantidade;
                }else if(codigo==5){
                    stock->minStockPalmilhas = minimo;
                    stock->palmilhasStock = quantidade;
                }   
                i++;
            }
            
        }else{
            puts("Error");          
        }      
    }else{
        puts(MSG_ERRO_LER_FICHEIRO);
    }
    fclose(fp);
}

Function to print the struct:

void mostrarStock(Stock stock){
    puts("==============  Stock : =============\n");
    puts("Codigo | Produto | Stock Minimo | Stock Atual\n");
    printf("1\tCouro\t\t%d\t\t%d\n", stock.minStockCouro, stock.couroStock);
    printf("2\tTecido\t\t%d\t\t%d\n", stock.minStockTecido, stock.tecidoStock);
    printf("3\tBorracha\t%d\t\t%d\n", stock.minStockBorracha, stock.borrachaStock);
    printf("4\tCordões\t\t%d\t\t%d\n", stock.minStockCordoes, stock.cordoesStock);
    printf("5\tPalmilhas\t%d\t\t%d\n", stock.minStockPalmilhas, stock.palmilhasStock);

}   

This is how i call the function in main:

int main(int argc, char** argv) {
    
    char *nomeFicheiro1 = "tabela_stocks.txt";
    Stock stock;
    carregarStock(&stock, nomeFicheiro1);
    mostrarStock(stock);
    
    return (EXIT_SUCCESS);
}

The function to print the struct doesn't print. I guess the error is in

fscanf(fp, "%d,%s ,%d,%d", &codigo, storeProduto, &minimo, &quantidade);

What am I doing wrong?

Answer 1

You could create a helper function to read out the two integers from one line.

bool get_two(FILE *stream, int* a, int* b) {
    return fscanf(stream, " %*[^,],%*[^,],%d,%d", a, b) == 2;
}

You then just need to call that 5 times.

Example:

#include <stdbool.h>
#include <stdio.h>

typedef struct {
    int couroStock;
    int minStockCouro;
    int tecidoStock;
    int minStockTecido;
    int borrachaStock;
    int minStockBorracha;
    int cordoesStock;
    int minStockCordoes;
    int palmilhasStock;
    int minStockPalmilhas;
} Stock;

bool get_two(FILE *stream, int* a, int* b) {
    return fscanf(stream, " %*[^,],%*[^,],%d,%d", a, b) == 2;
}

int main() {
    FILE *fp = fopen("tabela_stocks.txt", "r");
    if(fp) {
        Stock s;
        fscanf(fp, "%*[^\n]"); // skip first line

        if(get_two(fp, &s.couroStock, &s.minStockCouro) &&
           get_two(fp, &s.tecidoStock, &s.minStockTecido) &&
           get_two(fp, &s.borrachaStock, &s.minStockBorracha) &&
           get_two(fp, &s.cordoesStock, &s.minStockCordoes) &&
           get_two(fp, &s.palmilhasStock, &s.minStockPalmilhas))
        {
            printf("%d %d\n", s.couroStock, s.minStockCouro);
            printf("%d %d\n", s.tecidoStock, s.minStockTecido);
            printf("%d %d\n", s.borrachaStock, s.minStockBorracha);
            printf("%d %d\n", s.cordoesStock, s.minStockCordoes);
            printf("%d %d\n", s.couroStock, s.minStockCouro);
        }
        fclose(fp);
    }
}

If tabela_stocks.txt contains

Codigo,Produto,StockMinimo,StockAtual
1,Couro,300,1000
2,Tecido,250,2000
3,Borracha,200,500
4,Cordões,500,2000
5,Palmilhas,500,1000

Then the output will be

300 1000
250 2000
200 500
500 2000
300 1000

---

Since there are so many similarities between the different stocks in your Stock struct, you could break it down into smaller pieces and make a struct only holding information about one stock:

#include <stdbool.h>
#include <stdio.h>

typedef struct {
    int stock;
    int min_stock;
} Stock;

bool Stock_read(FILE *stream, Stock *s) {
    return fscanf(stream, " %*[^,],%*[^,],%d,%d", &s->stock, &s->min_stock) == 2;
}

void Stock_print(const Stock *s) {
    printf("%d %d\n", s->stock, s->min_stock);
}

With that you could create a Stocks type like this:

typedef struct {
    Stock Couro;
    Stock Tecido;
    Stock Borracha;
    Stock Cordoes;
    Stock Palmilhas;
} Stocks;

bool Stocks_read(FILE *stream, Stocks *s) {
    return
        Stock_read(stream, &s->Couro) &&
        Stock_read(stream, &s->Tecido) &&
        Stock_read(stream, &s->Borracha) &&
        Stock_read(stream, &s->Cordoes) &&
        Stock_read(stream, &s->Palmilhas);
}

void Stocks_print(const Stocks *s) {
    Stock_print(&s->Couro);
    Stock_print(&s->Tecido);
    Stock_print(&s->Borracha);
    Stock_print(&s->Cordoes);
    Stock_print(&s->Palmilhas);
}

and reading and printing would become simpler:

int main() {
    FILE *fp = fopen("tabela_stocks.txt", "r");
    if(fp) {
        Stocks s;
        fscanf(fp, "%*[^\n]"); // skip first line

        if(Stocks_read(fp, &s)) {
            Stocks_print(&s);
        }
        fclose(fp);
    }
}

Looking closer at the Stocks struct you may want to consider using an array instead:

typedef struct {
    Stock stocks[5];
} Stocks;

which would also simplify the rest of the code since you could loop over that array to read and print each Stock.