代码在 IDE 上运行，但不在 Linux 机器上运行 - C

Question

The code runs in Code::Blocks environment as expected. However on a Linux machine it is not working as expected.

Problem statement: On Linux, it does not read the input file.

Purpose: Read from the text file provided in the input and output two text files.

output_n.txt:

---List of Positive Cases---
--Flea X:+Positive+
--Anthony Kiedis:+Positive+
--Jack Irons:+Positive+
--Cliff Martinez:+Positive+

output_p.txt:

---List of Negative cases:---
--Chad Smith:-Neg-
--John Frusciante:-Neg-
--Arik Marshall:-Neg-

This is my source code:

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

#define SIZE 7

int c = 0;
char band_diagnose[SIZE];

int read_doctor_list(char filename[], char type[], char band_names[][20], char band_diagnose[])
{
    char line[100];
    int i = 0, j = 0;
    FILE *fp = fopen(filename, type);
    if (!filename)
    {
        printf("Fail to open the file");
        return 0;
    }
    else
    {
        while (fgets(line, 100, fp))
        {
            if (c % 2 == 0)
            {
                strcpy(band_names[i], line);
                strtok(band_names[i], "\n");
                i++;
            }
            else
            {
                if (!strcmp(line, "Positive\n"))
                {
                    band_diagnose[j] = 'P';
                }
                else if (!strcmpi(line, "Negative\n"))
                {
                    band_diagnose[j] = 'N';
                }

                j++;
            }

            c++;
        }

        return 1;
    }

    fclose(fp);
}

void band_practice_list(char filename[], char status[], char band_names[][20], char band_diagnose[])
{
    int i = 0;
    FILE *fp = fopen(filename, "w");
    if (!filename)
    {
        printf("Fail to open the file!");
    }
    else
    {
        if (!strcmp(status, "Positive"))
        {
            char pos[] = "+Positive+";
            fprintf(fp, "---List of Positive Cases---\n");
            for (i = 0; i < SIZE; i++)
            {
                if (band_diagnose[i] == 'P')
                {
                    fprintf(fp, "--%s:%s\n", band_names[i], pos);
                }
            }

            fclose(fp);
        }

        if (!strcmp(status, "Negative"))
        {
            rewind(fp);
            char neg[] = "-Neg-";
            fprintf(fp, "---List of Negative cases:---\n");

            for (i = 0; i < SIZE; i++)
            {
                if (band_diagnose[i] == 'N')
                {
                    fprintf(fp, "--%s:%s\n", band_names[i], neg);
                }
            }

            fclose(fp);
        }

        printf("Creating list...\n");
        for (i = 0; i < SIZE; i++)
        {
            if (band_diagnose[i] == 'P')
            {
                printf("%s:%c...Can't go to practice!:(\n\n", band_names[i], band_diagnose[i]);
            }
            else
            {
                printf("%s:%c...Good to go to practice!:)\n\n", band_names[i], band_diagnose[i]);
            }
        }
    }
}

int main(int argc, char **argv)
{
    char band_names[SIZE][20];
    char band_diagnose[SIZE];

    int n = read_doctor_list("doctorlist.txt", "r", band_names, band_diagnose);

    if (n)
    {
        band_practice_list("output_p.txt", "Positive", band_names, band_diagnose);
        band_practice_list("output_n.txt", "Negative", band_names, band_diagnose);
    }
}

This is the input file, doctorlist.txt:

Flea X
Positive
Anthony Kiedis
Positive
Chad Smith
Negative
John Frusciante
Negative
Jack Irons
Positive
Cliff Martinez
Positive
Arik Marshall
Negative

Screenshot of my program run in Code::Blocks:

In Linux enviromment:

Answer 1

Code runs on IDE but not on Linux machine

On Linux, you could edit your C code with GNU emacs or vim or gedit etc..., then compile your code with the GCC compiler invoked as gcc -Wall -Wextra -g (perhaps in a terminal) to get all warnings and debug info.

Read of course Modern C and see this reference . See also Advanced Linux Programming and man pages like syscalls(2) , fopen(3) , errno(3) etc....

You probably want to use perror(3) when fopen fails.

Improve your C code to get no warnings at all from gcc

Then, use the GDB debugger to understand the behavior of your program. You could run your program step by step, ask values of variables, etc... from the debugger.

Consider also using the Clang static analyzer .

Be aware that in 2021 UTF-8 is used everywhere . Maybe you want to accept some input like Gabrielles d'Estrées in your doctorlist.txt file?