man-pages/man2/readlink.2

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.\"     @(#)readlink.2	6.8 (Berkeley) 3/10/91
.\"
.\" Modified Sat Jul 24 00:10:21 1993 by Rik Faith (faith@cs.unc.edu)
.\" Modified Tue Jul  9 23:55:17 1996 by aeb
.\" Modified Fri Jan 24 00:26:00 1997 by aeb
.\"
.TH READLINK 2 1997-08-21 "Linux 2.0.30" "Linux Programmer's Manual"
.SH NAME
readlink \- read value of a symbolic link
.SH SYNOPSIS
.B #include <unistd.h>
.sp
.BI "ssize_t readlink(const char *" path ", char *" buf ", size_t " bufsiz );
.SH DESCRIPTION
.BR readlink ()
places the contents of the symbolic link
.I path
in the buffer
.IR buf ,
which has size
.IR bufsiz .
.BR readlink ()
does not append a null byte to
.IR buf .
It will truncate the contents (to a length of
.I bufsiz
characters), in case the buffer is too small to hold all of the contents.
.SH "RETURN VALUE"
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
.IR errno .
.SH ERRORS
.TP
.B EACCES
Search permission is denied for a component of the path prefix.
(See also
.BR path_resolution (2).)
.TP
.B EFAULT
.I buf
extends outside the process's allocated address space.
.TP
.B EINVAL
.I bufsiz
is not positive.
.TP
.B EINVAL
The named file is not a symbolic link.
.TP
.B EIO
An I/O error occurred while reading from the file system.
.TP
.B ELOOP
Too many symbolic links were encountered in translating the pathname.
.TP
.B ENAMETOOLONG
A pathname, or a component of a pathname, was too long.
.TP
.B ENOENT
The named file does not exist.
.TP
.B ENOMEM
Insufficient kernel memory was available.
.TP
.B ENOTDIR
A component of the path prefix is not a directory.
.SH "CONFORMING TO"
4.4BSD (the
.BR readlink ()
function call appeared in 4.2BSD),
POSIX.1-2001.
.SH NOTES
In versions of glibc up to and including glibc 2.4, the return type of
.BR readlink ()
was declared as
.IR int .
Nowadays, the return type is declared as
.IR ssize_t ,
as (newly) required in POSIX.1-2001.
.SH "SEE ALSO"
.BR lstat (2),
.BR path_resolution (2),
.BR readlinkat (2),
.BR stat (2),
.BR symlink (2)