bsd/man/man2/link.2

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  34 .\"     @(#)link.2      8.3 (Berkeley) 1/12/94
  35 .\"
  36 .Dd January 12, 1994
  37 .Dt LINK 2
  38 .Os BSD 4
  39 .Sh NAME
  40 .Nm link
  41 .Nd make a hard file link
  42 .Sh SYNOPSIS
  43 .Fd #include <unistd.h>
  44 .Ft int
  45 .Fn link "const char *name1" "const char *name2"
  46 .Sh DESCRIPTION
  47 The
  48 .Fn link
  49 function call
  50 atomically creates the specified directory entry (hard link)
  51 .Fa name2
  52 with the attributes of the underlying object pointed at by
  53 .Fa name1
  54 If the link is successful: the link count of the underlying object
  55 is incremented;
  56 .Fa name1
  57 and
  58 .Fa name2
  59 share equal access and rights
  60 to the
  61 underlying object.
  62 .Pp
  63 If
  64 .Fa name1
  65 is removed, the file
  66 .Fa name2
  67 is not deleted and the link count of the
  68 underlying object is
  69 decremented.
  70 .Pp
  71 .Fa Name1
  72 must exist for the hard link to
  73 succeed and
  74 both
  75 .Fa name1
  76 and
  77 .Fa name2
  78 must be in the same file system.
  79 As mandated by POSIX.1
  80 .Fa name1
  81 may not be a directory.
  82 .Sh RETURN VALUES
  83 Upon successful completion, a value of 0 is returned.  Otherwise,
  84 a value of -1 is returned and
  85 .Va errno
  86 is set to indicate the error.
  87 .Sh ERRORS
  88 .Fn Link
  89 will fail and no link will be created if:
  90 .Bl -tag -width Er
  91 .It Bq Er ENOTDIR
  92 A component of either path prefix is not a directory.
  93 .It Bq Er ENAMETOOLONG
  94 A component of a pathname exceeded
  95 .Dv {NAME_MAX}
  96 characters, or an entire path name exceeded
  97 .Dv {PATH_MAX}
  98 characters.
  99 .It Bq Er ENOENT
 100 A component of either path prefix does not exist.
 101 .It Bq Er EACCES
 102 A component of either path prefix denies search permission.
 103 .It Bq Er EACCES
 104 The requested link requires writing in a directory with a mode
 105 that denies write permission.
 106 .It Bq Er ELOOP
 107 Too many symbolic links were encountered in translating one of the pathnames.
 108 .It Bq Er ENOENT
 109 The file named by
 110 .Fa name1
 111 does not exist.
 112 .It Bq Er EEXIST
 113 The link named by
 114 .Fa name2
 115 does exist.
 116 .It Bq Er EPERM
 117 The file named by
 118 .Fa name1
 119 is a directory.
 120 .It Bq Er EXDEV
 121 The link named by
 122 .Fa name2
 123 and the file named by
 124 .Fa name1
 125 are on different file systems.
 126 .It Bq Er ENOSPC
 127 The directory in which the entry for the new link is being placed
 128 cannot be extended because there is no space left on the file
 129 system containing the directory.
 130 .ne 3v
 131 .It Bq Er EDQUOT
 132 The directory in which the entry for the new link
 133 is being placed cannot be extended because the
 134 user's quota of disk blocks on the file system
 135 containing the directory has been exhausted.
 136 .It Bq Er EIO
 137 An I/O error occurred while reading from or writing to
 138 the file system to make the directory entry.
 139 .It Bq Er EROFS
 140 The requested link requires writing in a directory on a read-only file
 141 system.
 142 .It Bq Er EFAULT
 143 One of the pathnames specified
 144 is outside the process's allocated address space.
 145 .El
 146 .Sh SEE ALSO
 147 .Xr symlink 2 ,
 148 .Xr unlink 2
 149 .Sh STANDARDS
 150 The
 151 .Fn link
 152 function is expected to conform to
 153 .St -p1003.1-88 .