编辑“︁C 语言错误处理最佳实践”︁（章节）

== 实际应用案例 ==

'''案例：安全文件复制程序'''
<syntaxhighlight lang="c">
#include <stdio.h>
#include <stdlib.h>

#define CHUNK_SIZE 1024

int copy_file(const char *src, const char *dst) {
    FILE *src_file = NULL, *dst_file = NULL;
    char *buffer = NULL;
    size_t bytes_read;
    
    src_file = fopen(src, "rb");
    if (!src_file) goto error;
    
    dst_file = fopen(dst, "wb");
    if (!dst_file) goto error;
    
    buffer = malloc(CHUNK_SIZE);
    if (!buffer) goto error;
    
    while ((bytes_read = fread(buffer, 1, CHUNK_SIZE, src_file)) > 0) {
        if (fwrite(buffer, 1, bytes_read, dst_file) != bytes_read) {
            goto error;
        }
    }
    
    free(buffer);
    fclose(src_file);
    fclose(dst_file);
    return 0;
    
error:
    if (buffer) free(buffer);
    if (src_file) fclose(src_file);
    if (dst_file) fclose(dst_file);
    perror("File copy failed");
    return -1;
}
</syntaxhighlight>