table of contents
|READLINK(2)||System Calls Manual||READLINK(2)|
NAME¶readlink, readlinkat — 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); ssize_t
readlinkat(int fd, const char *restrict path, char *restrict buf, size_t bufsize);
DESCRIPTION¶The readlink() system call places the contents of the symbolic link path in the buffer buf, which has size bufsiz. The readlink() system call does not append a
NULcharacter to buf. The readlinkat() system call is equivalent to readlink() except in the case where path specifies a relative path. In this case the symbolic link whose content is read relative to the directory associated with the file descriptor fd instead of the current working directory. If readlinkat() is passed the special value
AT_FDCWDin the fd parameter, the current working directory is used and the behavior is identical to a call to readlink().
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.
ERRORS¶The readlink() system call will fail if:
- A component of the path prefix is not a directory.
- A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
- The named file does not exist.
- Search permission is denied for a component of the path prefix.
- Too many symbolic links were encountered in translating the pathname.
- The named file is not a symbolic link.
- An I/O error occurred while reading from the file system.
- The buf argument extends outside the process's allocated address space.
- The path argument does not specify an
absolute path and the fd argument is neither
AT_FDCWDnor a valid file descriptor open for searching.
- The path argument is not an absolute
path and fd is neither
AT_FDCWDnor a file descriptor associated with a directory.
SEE ALSO¶lstat(2), stat(2), symlink(2), symlink(7)
STANDARDS¶The readlinkat() system call follows The Open Group Extended API Set 2 specification.
HISTORY¶The readlink() system call appeared in 4.2BSD. The readlinkat() system call appeared in FreeBSD 8.0.
|April 10, 2008||Debian|