xref: /illumos-gate/usr/src/man/man2/readlink.2 (revision faac71c002f7c7a98741f991b25937b24f309df0)
te
Copyright 1989 AT&T. Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved. Portions Copyright (c) 1992, X/Open Company Limited. All Rights Reserved.
Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.
The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
This notice shall appear on any product containing this material.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
READLINK 2 "Dec 1, 2003"
NAME
readlink - read the contents of a symbolic link
SYNOPSIS

#include <unistd.h>

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

The readlink() function places the contents of the symbolic link referred to by path in the buffer buf which has size bufsiz. If the number of bytes in the symbolic link is less than bufsiz, the contents of the remainder of buf are left unchanged. If the buf argument is not large enough to contain the link content, the first bufsize bytes are placed in buf.

RETURN VALUES

Upon successful completion, readlink() returns the count of bytes placed in the buffer. Otherwise, it returns -1, leaves the buffer unchanged, and sets errno to indicate the error.

ERRORS

The readlink() function will fail if: EACCES

Search permission is denied for a component of the path prefix of path.

EFAULT

path or buf points to an illegal address.

EINVAL

The path argument names a file that is not a symbolic link.

EIO

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

ENOENT

A component of path does not name an existing file or path is an empty string.

ELOOP

A loop exists in symbolic links encountered during resolution of the path argument.

ENAMETOOLONG

The length of path exceeds {PATH_MAX}, or a pathname component is longer than {NAME_MAX} while _POSIX_NO_TRUNC is in effect.

ENOTDIR

A component of the path prefix is not a directory.

ENOSYS

The file system does not support symbolic links.

The readlink() function may fail if: EACCES

Read permission is denied for the directory.

ELOOP

More than {SYMLOOP_MAX} symbolic links were encountered in resolving path.

ENAMETOOLONG

As a result of encountering a symbolic link in resolution of the path argument, the length of the substituted pathname string exceeded {PATH_MAX}.

USAGE

Portable applications should not assume that the returned contents of the symbolic link are null-terminated.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Standard
MT-Level Async-Signal-Safe
SEE ALSO

stat(2), symlink(2), attributes(5), standards(5)