尝试在 C 中使用 fopen 打开文件后程序退出

Question

I'm a newbie programming in C. I'm trying to read the lines of a file. Using the code below, if the file exists, everything is OK. However, if the file does not exist, the program quits, without any error message. I expected to get a null in the variable and the program continue running.

I'm programming in C compiling with gcc in a raspberry with raspbian.

Am I doing somethig wrong?

void readValues(void)
{
    FILE * fp;
    char * line = NULL;
    size_t len = 0;
    ssize_t read;
    int i=0;
    
    fp = fopen("/tmp/valores.txt", "r");
    // If the file valores does not exist, the execution quits here

    if (fp != NULL)
    {
       while ((read = getline(&line, &len, fp)) != -1)
       {
           printf("%s", line);
           values[i] = atoi(line);
        
           i++;
        }
    }
    else
    {
        printf("Could not open file");
    }

    fclose(fp);
    if (line)
        free(line);    
}

In case the file is not present, what I want to do is that the program stays running.

Answer 1

You executed fclose(fp); regardless of whether fp is NULL .

Your printf() statement don't have newline, so there are high chance that the string is buffered and not outputted when execution is aborted.

You should move fclose(fp); inside the block corresponding to if (fp != NULL) like

    if (fp != NULL)
    {
       while ((read = getline(&line, &len, fp)) != -1)
       {
           printf("%s", line);
           values[i] = atoi(line);
        
           i++;
        }
        fclose(fp); /* add this */
    }
    else
    {
        printf("Could not open file");
    }

    /* remove this */
    /* fclose(fp); */