NAME
readlink() — read the contents of a symbolic link
SYNOPSIS
#include <unistd.h>
int readlink(
const char *path,
char *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 unspecified.
RETURN VALUE
Upon successful completion,
readlink()
returns the count of bytes placed in the buffer.
Otherwise, it returns a value of -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.
- [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]
Too many symbolic links were encountered in resolving path.
- [ENAMETOOLONG]
The length of path exceeds
PATH_MAX,
or a pathname component is longer than
NAME_MAX.
- [ENOTDIR]
A component of the path prefix is not a directory.
The
readlink()
function may fail if:
- [EACCES]
Read permission is denied for the directory.
- [ENAMETOOLONG]
Pathname resolution of a symbolic link produced an
intermediate result whose length exceeds
PATH_MAX.
APPLICATION USAGE
Portable applications should not assume that the
returned contents of the symbolic link are null- terminated.
CHANGE HISTORY
First released in Issue 4, Version 2.
readlink HP-UX EXTENSIONS
DESCRIPTION
If the length of the path name string is less than
bufsiz,
the string will be null-terminated when returned.
If the length of the path name string is exactly
bufsiz,
the string will not be null-terminated when returned.
ERRORS
- [EACCES]
Search permission is denied for a component of the path prefix.
- [EFAULT]
buf
or
path
points outside the process's allocated address space.
Reliable detection of this error is implementation-dependent.
- [ENAMETOOLONG]
A component of
path
exceeds
NAME_MAX
bytes while
_POSIX_NO_TRUNC
is in effect, or
path
exceeds
PATH_MAX
bytes.
AUTHOR
readlink()
was developed by the University of California, Berkeley.
STANDARDS CONFORMANCE
readlink(): AES, SVID3
