convert const char* to int

Question

I read from CSV file with 4 column (integers). The read function works but when I try to insert char values into array (of integers) return this error

a value of type "const char *" cannot be assigned to an entity of type "float"

I try to use atoi but return list of 0000, 1111 etc. Can you suggest me some solution? the code:

const char* getfield(char* line, int num)
{
    const char* tok;
    for (tok = strtok(line, ",");
            tok && *tok;
            tok = strtok(NULL, ";\n"))
    {
        if (!--num)
            return (tok);
    }
    return NULL;
}


int main(void)
{

    FILE *pf=fopen("Trajectory_1.csv","r");         
    char line[1024];

    if(pf==NULL){
        printf("ERROR MESSAGE");
        exit(1);
    }
    int x=0;
    while(fgets(line,sizeof(line),pf)){
        char* tmp=strdup(line);
        printf("%s",getfield(tmp,1));
        t_h[x]=getfield(tmp,1);
        free(tmp);
        x++;
    }
    fclose(pf);
}

in this case only the first column

EDIT the code will be

double getfield(char* line, int num)
{
    const char* tok;
    for (tok = strtok(line, ","); //comam separator
            tok && *tok;
            tok = strtok(NULL, ";\n"))
    {
        if (!--num)
            return (atof(tok));
    }
    return NULL;
}

FILE *pf=fopen("//home//user//Documenti//Bello//Dataset1//Trajectories//Trajectory_1.csv","r"); //rivedere
    char line[1024];

    if(pf==NULL){
        printf("ERR MSG");  // I change this like William suggest
        exit(1);
    }

int x=0;

    while(fgets(line,sizeof(line),pf)){

        double d=getfield(line,1)); // I did not understand

    }
    fclose(pf);

Answer 1

getField is to return the floating point value of the CSV column identified by num . getField is called each time with a new line to parse.

Then the function should return a double, namely return(atof(tok)); (and be declared as double getfield(.. );

You must remove your print statement, as it calls getField but getField modifies the string (through strtok). Also there seems no need to call strdup ; just let getField work on line .

Note: I am not a strtok specialist but the second call (in the for statement) may be wrong and may also need the comma as a terminator.