C++ 覆盖读取函数，但当文件描述符为3或4时，我有问题

我想覆盖netstat-Tunap的读取函数，当我为netstat-Tunap运行strace时，我感兴趣的覆盖部分就是这里的这一部分，

openat(AT_FDCWD, "/proc/net/tcp", O_RDONLY) = 3
read(3, "  sl  local_address rem_address "..., 4096) = 300
write(1, "tcp        0      0 192.168.32.1"..., 101tcp        0      0 192.168.32.128:59904    192.168.32.129:9001     ESTABLISHED 17186/python ) = 101
read(3, "", 4096)                       = 0
close(3)

我想要的是在这里查看这行缓冲区的内容

read(3, "  sl  local_address rem_address "..., 4096) = 300

但是我LD_PREALOADING的读取库只给我打印文件描述符为5的读取缓冲区，文件描述符为5的读取是这样的

read(5, "unconfined\n", 4095)           = 11

我如何修复它，让它也打印文件描述符为3的缓冲区？

这是我在图书馆使用的程序，

#define _GNU_SOURCE
#include <stdio.h>
#include <dlfcn.h>
#include <unistd.h>

static ssize_t (*read_original)(int fd, void *buf, size_t count) = NULL;

ssize_t read(int fd, void *buf, size_t count) {
    ssize_t result;

    // Initialize the original read function if it hasn't been already
    if (!read_original) {
        read_original = dlsym(RTLD_NEXT, "read");
        if (!read_original) {
            fprintf(stderr, "Error: Unable to load the original read function\n");
            return -1;
        }
    }

    // Call the original read function
    result = read_original(fd, buf, count);

    // Print the buffer's contents for non-zero reads
    if (result > 0 && (fd == 3 || fd == 4 || fd == 5)) {
        printf("Read from fd %d, %zd bytes: ", fd, result);
        for (ssize_t i = 0; i < result; ++i) {
            printf("%02x ", ((unsigned char *)buf)[i]);
        }
        printf("\n");
    }

    return result;
}

我创建的库如下所示

gcc -shared -fPIC -o hider.so hide_read4.c -ldl个

我就是这样经营的

LD_PRELOAD=/path/to/lib/hider.so netstat -tunap个

这是我运行此命令时的输出

Read from fd 5, 11 bytes: 75 6e 63 6f 6e 66 69 6e 65 64 0a 
Read from fd 5, 11 bytes: 75 6e 63 6f 6e 66 69 6e 65 64 0a 
Read from fd 5, 11 bytes: 75 6e 63 6f 6e 66 69 6e 65 64 0a 
(Not all processes could be identified, non-owned process info will not be shown, you would have to be root to see it all.)
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 ip1:59904    ip2:9001     ESTABLISHED 17186/python        
udp        0      0 ip1:68       ip3:67       ESTABLISHED -