readlink - 讀符號鏈接的值

內容簡介

#include <unistd.h>

ssize_t readlink(const char **path*, char **buf*, size_t bufsiz**);**

描述

readlink () places the contents of the symbolic link  path  in the buffer  buf , which has size bufsiz .  readlink () does not append a null byte to  buf . It will truncate the contents (to a length of  bufsiz  characters), in case the buffer is too small to hold all of the contents.

返回值

The call returns the count of characters placed in the buffer if it succeeds, or a -1 if an error occurs, placing the error code in  errno .

錯誤

標籤

描述

EACCES

搜索權限的路徑前綴的組成部分將被拒絕. (See also path_resolution(2).)

EFAULT

buf 進程的已分配地址空間之外延伸.

EINVAL

bufsiz is not positive.

EINVAL

The named file is not a symbolic link.

EIO

An I/O error occurred while reading from the file system.

ELOOP

Too many symbolic links were encountered in translating the pathname.

ENAMETOOLONG

 

路徑名，或路徑名的組成部分太長。

ENOENT

指定的文件不存在。

ENOMEM

沒有足夠的內核內存可用。

ENOTDIR

 

路徑前綴的某組成部分不是目錄。

遵循於

4.4BSD (the  readlink () function call appeared in 4.2BSD), POSIX.1-2001.

HISTORY

In versions of glibc up to and including glibc 2.4, the return type of  readlink () was declared as  int . Nowadays, the return type is declared as  ssize_t , as (newly) required in POSIX.1-2001.

另請參閱

• lstat (2)

• path_resolution (2)

• readlinkat (2)

• stat (2)

• symlink (2)