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
  neither to be on the same file system nor to exist.
symlinkat() works the same way as
    symlink() except if path2 is
    relative. In that case, it is looked up from a directory whose file
    descriptor was passed as fd. Search permission is
    required on this directory. fd can be set to
    AT_FDCWD in order to specify the current
  directory.
The symlink() and symlinkat()
  functions return the value 0 if successful; otherwise the
  value -1 is returned and the global variable
  errno is set to indicate the error.
symlink() and symlinkat() will
  fail and no link will be created if:
  - [EACCES]
- A component of the name2 path prefix denies search
      permission.
- [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. Or, 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. Or, the
      user's quota of inodes on the file system on which the symbolic link is
      being created has been exhausted.
- [EEXIST]
- name2 already exists.
- [EFAULT]
- name1 or name2 points outside
      the process's allocated address space.
- [EIO]
- An I/O error occurred while making the directory entry for
      name2, or allocating the inode for
      name2, or writing out the link contents of
      name2. Or, an I/O error occurred while making the
      directory entry or allocating the inode.
- [ELOOP]
- Too many symbolic links were encountered in translating the pathname.
- [ENAMETOOLONG]
- A component of a pathname exceeded {NAME_MAX}
      characters, or an entire path name exceeded
      {PATH_MAX} characters.
- [ENOENT]
- A component of the name2 path does not exist.
- [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. Or, the new symbolic link cannot be created
      because there there is no space left on the file system that will contain
      the symbolic link. Or, there are no free inodes on the file system on
      which the symbolic link is being created.
- [ENOTDIR]
- A component of the name2 prefix is not a
    directory.
- [EROFS]
- The file name2 would reside on a read-only file
      system.
In addition, symlinkat() will fail if:
  - [EBADF]
- name2 does not specify an absolute path and
      fd is neither AT_FDCWDnor a
      valid file descriptor open for reading or searching.
- [ENOTDIR]
- name2 is not an absolute path and
      fd is a file descriptor associated with a
      non-directory file.
Thesymlink() function conforms to IEEE
  Std 1003.1-1990 (“POSIX.1”).
  symlinkat() conforms to IEEE Std
  1003.1-2008 (“POSIX.1”).
The symlink() function call appeared in
  4.2BSD.