C语言读取多行文本文件时遇EXC_BAD_ACCESS错误求助

云上老周

2026-5-15

解决C语言读取文件时EXC_BAD_ACCESS错误的问题

Hey Danwoo, let's figure out why you're hitting that EXC_BAD_ACCESS error in Xcode—this is almost certainly a code issue, not an environment problem. Let's break it down:

First, what does that error mean?

EXC_BAD_ACCESS(code=1, address=0x68) tells you your program is trying to access memory it shouldn't. In your case, this happens because you're calling fgetc() on an invalid file pointer.

The problems in your code:

You never check if the file opened successfully
If test1.txt isn't in the right location (Xcode runs programs from a specific build directory, not where your source file is) or the file doesn't exist, fopen() returns NULL. Calling fgetc(NULL) is exactly what triggers that memory access crash.
str1 is the wrong type
fgetc() returns an int, not a char. This is because EOF is an integer value (usually -1), and if your system uses unsigned char, comparing a char to EOF will never be true—leading to an infinite loop once you fix the first issue.

Fixed code:

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

int main(){ 
    FILE *fptr; 
    int str1; // 改为int类型，正确处理EOF
    
    // 打开文件并检查是否成功
    fptr = fopen("test1.txt", "r");
    if (fptr == NULL) {
        printf("Error: 无法打开文件！\n");
        return 1; // 带错误码退出
    }

    printf("\n The content of the file is :\n"); 
    str1 = fgetc(fptr); 
    while (str1 != EOF) { 
        printf("%c", str1); 
        str1 = fgetc(fptr); 
    } 
    printf("\n\n"); 
    fclose(fptr); 
    return 0; 
}