使用close()关闭文件异常：传入无效FD却关闭最后打开文件

我的程序维护着一个已打开文件的列表，调用close()时并未关闭传入的文件描述符（FD），反而关闭了编号最大的文件。当传入超出范围的FD时，不会弹出perror错误提示，而是直接关闭最后打开的文件。

closeFd函数代码 #

bool closeFd(List *fileList, int position)
{
    Pos p;

    p = findPosition(position, *listaFicheros);

    if (close(p->data.fileDescriptor) == (-1)) 
    {
        perror("File non-existent");
        return false;
    }
    else
    {

        deleteAtPosition(p, fileList);
        return true;
    }
}

测试输出 #

> open try.txt cr
Added entry 3 to the open files table
-> open try2.txt tr
Added entry 4 to the open files table
-> open
descriptor: 0 -> standard input
descriptor: 1 -> standard output
descriptor: 2 -> standard error 
descriptor: 3 -> try.txt O_CREAT
descriptor: 4 -> try2.txt O_TRUNC
-> close 8
-> open
descriptor: 0 -> standard input
descriptor: 1 -> standard output
descriptor: 2 -> standard error 
descriptor: 3 -> try.txt O_CREAT
-> close 6
-> open
descriptor: 0 -> standard input
descriptor: 1 -> standard output
descriptor: 2 -> standard error 
-> close 9 
-> open
descriptor: 0 -> standard input
descriptor: 1 -> standard output
-> 

注：close [fd]命令用于关闭对应文件描述符的文件，例如close 2应关闭标准错误；若为无效FD应弹出perror提示。但实际传入无效FD时，会关闭最后打开的文件。

辅助函数代码 #

findPosition函数 #

Pos findPosition(int position, List L)
{
    Pos p;

    p = L;
    while (p->data.position != position && p->next != NULL)
        p = p->next;
    
    return p;
}

deleteAtPosition函数 #

void deleteAtPosition(Pos p, List *L)
{
    Pos q;

    if (p == *L)
        *L = (*L)->next;
    else if (p->next == NULL)
    {
        q = previous(p, *L);
        q->next = NULL;
    }
    else
    {
        q = p->next;
        p->data = q->data;
        p->next = q->next;
        p = q;
    }
    free(p);
}

previous函数 #

Pos previous(Pos p, List L)
{
    Pos q;
    if (p == L)
        return NULL;
    else
    {
        for (q = L; q->next != p; q = q->next)
            ;
        return q;
    }
}

链表头文件代码 #

#define COMMAND_LENGTH 50

typedef char command[COMMAND_LENGTH];

typedef struct Item
{
    command name;
    int fileDescriptor;
    int position;
    int mode;
} Item;

typedef struct Node *Pos;
struct Node
{
    Pos next;
    Item data;
};
typedef Pos List;

内容的提问来源于stack exchange，提问作者jamondebellota