Edit C. csv files

Question

I need to make a programming code in C, in which I ask the user the name of a city, present in the first file (cities.csv), and I have to remove the id of the city inserted. Then this id has to match another id, present in a second file (meteorology.csv), and then edit the weather information, present in the second file. I’ve been doing a lot of research and with some help, I was able to get the code below. However, when I compile it, everything in the second file is overwritten with the data from the first file. Could someone help me?

#define TAM_STR 100

typedef struct city_t{
char city_id[TAM_STR];
char city_name[TAM_STR];
char county_name[TAM_STR];
char district_name[TAM_STR]; } city_t;

typedef struct meteo_t{
char meteo_id[TAM_STR];
char meteo_city_id[TAM_STR];
char tempt_max[TAM_STR];
char tempt_min[TAM_STR];
char humidity[TAM_STR];
char preassure[TAM_STR];
char date[11]; } meteo_t;

int editInfo(){
char city[100];    

struct city_t INFO;
struct meteo_t DATA;

printf("Qual e a cidade: ");
scanf("%[^\n]%*c", city);

FILE* stream = fopen("cidades.csv", "r");
FILE* meteo =fopen ("meteorologia.csv","w");

if("cidades.csv" == NULL || "meteorologia.csv" == NULL)
{
    printf("Nao e possivel abrir o ficheiro\n");
    return -1;
}

char line[1024];
while (fgets(line, 1024, stream) != NULL)
{
    sscanf(line, "%s", INFO.city_name);
    if(strcmp(city, INFO.city_name) == 0)
    { //pelo que me disseram, falta aqui um while
        sscanf(line, "%s,%s,%s,%s,%s", DATA.tempt_max, DATA.tempt_min, DATA.humidity, DATA.preassure, DATA.date);
        printf("Introduza o valor da temperatura maxima: ");
                scanf("%s", DATA.tempt_max);
                printf("Introduza o valor da temperatura minima: ");
                scanf("%s", DATA.tempt_min);
                printf("Introduza o valor da humidade: ");
                scanf("%s", DATA.humidity);
                printf("Introduza o valor da pressao: ");
                scanf("%s", DATA.preassure);
                printf("Introduza a data correspondente, no formato AAAA-MM-DD: ");
                scanf("%s", DATA.date);

                fprintf(meteo, "%s,%s,%s,%s,%s", DATA.tempt_max, DATA.tempt_min, DATA.humidity, DATA.preassure, DATA.date);
                printf("Informacao alterada com sucesso!");

                fclose(stream);
                fclose(meteo);
    }
    else
    {
        fputs(line, meteo);
    }
}           
}

The.csv cities file has 152 rows and 4 columns in this format:

id_cidade,cidade,concelho,distrito

as an example:

98,Porto,Porto,Porto

The weather file has 152 lines and 7 columns, with this format:

id_meteo,id_cidade,temp_max,tem_min,humidade,pressao,data

as an example:

98,98,9.5,0.3,62,1025,2018-02-12

Any help is welcome. Thank you!

Answer 1

It had several errors.
There was an error in sscanf that made the input received by reading the file cities.csv the city code instead of the name.
After that it had an if that compared the input written by Sario with the name of the city with the input of the file, in this case the code of the city.
Else made it copy the file line cities.csv for meteorology.csv
And a few more errors follow the code corrected and functional
I forgot to mention the error in your.csv city file for some reason when entering the information without commas, for example, "98,Port,Port,Port" gives an error in SCANF
The right thing would be to insert the information with spaces after the commas, for example, "98, Porto, Porto, Porto"
I hope it works now

#include <stdio.h>
#include <string.h>

#define TAM_STR 100

typedef struct city_t{
char city_id[TAM_STR];
char city_name[TAM_STR];
char county_name[TAM_STR];
char district_name[TAM_STR]; } city_t;

typedef struct meteo_t{
char meteo_id[TAM_STR];
char meteo_city_id[TAM_STR];
char tempt_max[TAM_STR];
char tempt_min[TAM_STR];
char humidity[TAM_STR];
char preassure[TAM_STR];
char date[11]; } meteo_t;

int editInfo(){
char city[100];    

struct city_t INFO;
struct meteo_t DATA;

printf("Qual e a cidade: ");
scanf("%[^\n]%*c", city);

FILE* stream = fopen("cidades.csv", "r");
FILE* meteo = fopen("meteorologia.csv","w");

if("cidades.csv" == NULL || "meteorologia.csv" == NULL)
{
    printf("Nao e possivel abrir o ficheiro\n");
    return -1;
}

char line[1024];
while (fgets(line, 1024, stream) != NULL)
{
    sscanf(line, "%s%s", INFO.city_id, INFO.city_name);

    char *pointerComma = NULL;
    char *pointerCityName = NULL;
    pointerComma = strchr(INFO.city_name, ',');
    pointerCityName = INFO.city_name;

    int indexComma = pointerComma - pointerCityName;
    INFO.city_name[indexComma] = 0;

    if(strcmp(city, INFO.city_name) == 0)
    { //pelo que me disseram, falta aqui um while
        sscanf(line, "%s %s %s %s %s", DATA.tempt_max, DATA.tempt_min, DATA.humidity, DATA.preassure, DATA.date);
        printf("Introduza o valor da temperatura maxima: ");
        scanf("%s", DATA.tempt_max);
        printf("Introduza o valor da temperatura minima: ");
        scanf("%s", DATA.tempt_min);
        printf("Introduza o valor da humidade: ");
        scanf("%s", DATA.humidity);
        printf("Introduza o valor da pressao: ");
        scanf("%s", DATA.preassure);
        printf("Introduza a data correspondente, no formato AAAA-MM-DD: ");
        scanf("%s", DATA.date);

        fprintf(meteo, "%s,%s,%s,%s,%s", DATA.tempt_max, DATA.tempt_min, DATA.humidity, DATA.preassure, DATA.date);
        printf("Informacao alterada com sucesso!");

        fclose(stream);
        fclose(meteo);
    }
}

return 0;        
}


int main() {

editInfo();
return 0;
}