readlink(2) System Calls readlink(2)NAMEreadlink - 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 sys‐
tem.
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 res‐
olution 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 resolu‐
tion of the path argument, the length of the substi‐
tuted 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 ALSOstat(2), symlink(2), attributes(5), standards(5)SunOS 5.10 1 Dec 2003 readlink(2)
