symlink
, symlinkat
—
make symbolic link to a file
Standard C Library (libc, -lc)
#include <unistd.h>
int
symlink
(const
char *name1, const char
*name2);
int
symlinkat
(const
char *name1, int
fd, const char
*name2);
A symbolic link name2 is created to
name1 (name2 is the name of the
file created, name1 is the string used in creating the
symbolic link). Either name may be an arbitrary path name; the files need not
be on the same file system.
The symlinkat
() system call is equivalent
to symlink
() except in the case where
name2 specifies a relative path. In this case the
symbolic link is created relative to the directory associated with the file
descriptor fd instead of the current working
directory. If symlinkat
() is passed the special
value AT_FDCWD
in the fd
parameter, the current working directory is used and the behavior is
identical to a call to symlink
().
The symlink
() function returns the value 0 if
successful; otherwise the value -1 is returned and the global variable
errno is set to indicate the error.
The symbolic link succeeds unless:
- [
ENOTDIR
]
- A component of the name2 path prefix is not a
directory.
- [
ENAMETOOLONG
]
- A component of the name2 pathname exceeded 255
characters, or the entire length of either path name exceeded 1023
characters.
- [
ENOENT
]
- A component of the name2 path prefix does not
exist.
- [
EACCES
]
- A component of the name2 path prefix denies search
permission, or write permission is denied on the parent directory of the
file to be created.
- [
ELOOP
]
- Too many symbolic links were encountered in translating the
name2 path name.
- [
EEXIST
]
- The path name pointed at by the name2 argument
already exists.
- [
EPERM
]
- The parent directory of the file named by name2 has
its immutable flag set, see the
chflags(2)
manual page for more information.
- [
EIO
]
- An I/O error occurred while making the directory entry for
name2, allocating the inode for
name2, or writing out the link contents of
name2.
- [
EROFS
]
- The file name2 would reside on a read-only file
system.
- [
ENOSPC
]
- The directory in which the entry for the new symbolic link is being placed
cannot be extended because there is no space left on the file system
containing the directory.
- [
ENOSPC
]
- The new symbolic link cannot be created because there is no space left on
the file system that will contain the symbolic link.
- [
ENOSPC
]
- There are no free inodes on the file system on which the symbolic link is
being created.
- [
EDQUOT
]
- The directory in which the entry for the new symbolic link is being placed
cannot be extended because the user's quota of disk blocks on the file
system containing the directory has been exhausted.
- [
EDQUOT
]
- The new symbolic link cannot be created because the user's quota of disk
blocks on the file system that will contain the symbolic link has been
exhausted.
- [
EDQUOT
]
- The user's quota of inodes on the file system on which the symbolic link
is being created has been exhausted.
- [
EINTEGRITY
]
- Corrupted data was detected while reading from the file system.
- [
EFAULT
]
- The name1 or name2 argument
points outside the process's allocated address space.
In addition to the errors returned by the
symlink
(), the symlinkat
()
may fail if:
- [
EBADF
]
- The name2 argument does not specify an absolute path
and the fd argument is neither
AT_FDCWD
nor a valid file descriptor open for
searching.
- [
ENOTDIR
]
- The name2 argument is not an absolute path and
fd is neither
AT_FDCWD
nor a
file descriptor associated with a directory.
The symlinkat
() system call follows The Open Group
Extended API Set 2 specification.
The symlink
() system call appeared in
4.2BSD. The symlinkat
() system
call appeared in FreeBSD 8.0.