READLINK(2)

READLINK(2) | NetBSD System Calls Manual | READLINK(2)

# NAME

readlink — read value of a symbolic link

# LIBRARY

Standard C Library (libc, -lc)

# SYNOPSIS

#include <unistd.h>

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

# DESCRIPTION

readlink() places the contents of the symbolic link path in the buffer buf, which has size bufsiz. readlink() does not append a NUL character to buf.

# RETURN VALUES

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 the global variable errno.

# EXAMPLES

A typical use is illustrated in the following piece of code which reads the contents of a symbolic link named /symbolic/link and stores them as null-terminated string:

    #include <limits.h>
    #include <unistd.h>

    char buf[PATH_MAX];
    ssize_t len;

    if ((len = readlink("/symbolic/link", buf, sizeof(buf)-1)) == -1)
    	error handling;
    buf[len] = '\0';

# ERRORS

readlink() will fail if:

[ENOTDIR]
  A component of the path prefix is not a directory.
[ENAMETOOLONG]
  A component of a pathname exceeded {NAME_MAX} characters, or an entire path name exceeded {PATH_MAX} characters.
[ENOENT]
  The named file does not exist.
[EACCES]
  Search permission is denied for a component of the path prefix.
[ELOOP]
  Too many symbolic links were encountered in translating the pathname.
[EINVAL]
  The named file is not a symbolic link.
[EIO]
  An I/O error occurred while reading from the file system.
[EFAULT]
  buf extends outside the process's allocated address space.

# SEE ALSO

lstat(2), stat(2), symlink(2), symlink(7)

# STANDARDS

The readlink() function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).

# HISTORY

The readlink() function appeared in 4.2BSD. The type returned was changed from int to ssize_t in NetBSD 2.1.

May 11, 2004 | NetBSD 5.99