C语言 读取文件会导致 seg 错误

Question

所以我有一个文本文件：

5f6
2f8
2f2

我正在读取值：5,6,2,8,2，其中前两个数字始终是行 x 列，然后我尝试在回顾文件值时绘制矩形（这有效，但是在运行程序并打印它们时，它会出错）。

#include <stdio.h>
#include <ncurses.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char * argv[])
{
    initscr();
    cbreak();
    noecho();
    char str[100];
    static char * row;
    static char * col;
    static int i;
    static int j;
    static int k;
    static int x; 
    static int y;
    int count = 0;
    FILE* file;
    file = fopen(argv[1],"r");
    if(file == NULL)
    {
        mvprintw(0,0,"File returns null pointer");
        exit(1);
    }
    while(!feof(file))
    {
        fgets(str,100,file);
        row = strtok(str,"x");
        col = strtok(NULL," n");
        x = atol(row);
        y = atol(col);
        for(j=0;j<x;j++)
        {
            for(k=0;k<y;k++)
            {
                mvprintw(k+5,j+5+count,".");
                refresh(); //Space out drawing each rectangle? so they don't overlap
            }
        }
        count+=5;
    }
    fclose(file);
    getch();
    endwin();
    return (0);
}

我不太确定如何在这里进行，我将如何消除这个 seg 错误，并可能间隔出生成的绘图（count 变量似乎没有这样做）。

Answer 1

您的分段错误是因为您没有检查strtok()是否返回NULL并且仍然使用 atol() 取消引用指针，这是如何正确执行此操作的示例

#include <stdio.h>
#include <ncurses.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char * argv[])
{
    char  str[100];
    int   j;
    int   k;
    int   count;
    FILE *file;
    file = fopen(argv[1],"r");
    if (file == NULL)
     {
        mvprintw(0, 0, "File returns null pointer");
        return 1;
     }
    initscr();
    cbreak();
    noecho();
    count = 0;
    while(fgets(str, sizeof(str), file) != NULL)
     {
        char *endptr;
        char *row;
        char *col;
        int   x;
        int   y;
        row = strtok(str, "f");
        if (row == NULL)
         {
            fprintf(stderr, "`%s' does not contain `f'n", str);
            continue;
         }
        col = strtok(NULL, " n");
        if (col == NULL)
         {
            fprintf(stderr, "`%s' caused an unexpected errorn", str);
            continue;
         }
        x = strtol(row, &endptr, 10);
        if (*endptr != '')
         {
            fprintf(stderr, "Cannot convert `%s' to integern", row);
            continue;
         }
        y = strtol(col, &endptr, 10);
        if (*endptr != '')
         {
            fprintf(stderr, "Cannot convert `%s' to integern", col);
            continue;
         }
        for (j = 0 ; j  < x ; j++)
         {
            for (k = 0 ; k < y ; k++)
             {
                mvprintw(k + 5, j + 5 + count, ".");
                refresh();
             }
         }
        count+=5;
     }
    fclose(file);
    getch();
    endwin();
    return 0;
}