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readlink()函数 Unix/Linux

readlink - 读符号链接的值

内容简介

#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 sizebufsizreadlink() 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.

错误

标签 描述
EACCES 搜索权限的路径前缀的组成部分将被拒绝. (See also path_resolution(2).)
EFAULT buf 进程的已分配地址空间之外延伸.
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
  路径名,或路径名的组成部分太长。
ENOENT 指定的文件不存在。
ENOMEM 没有足够的内核内存可用。
ENOTDIR
  路径前缀的某组成部分不是目录。

遵循于

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.

另请参阅