bsd/man/man2/symlink.2

   1 .\"     $NetBSD: symlink.2,v 1.7 1995/02/27 12:38:34 cgd Exp $
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  34 .\"     @(#)symlink.2   8.1 (Berkeley) 6/4/93
  35 .\"
  36 .Dd June 4, 1993
  37 .Dt SYMLINK 2
  38 .Os BSD 4.2
  39 .Sh NAME
  40 .Nm symlink ,
  41 .Nm symlinkat
  42 .Nd make symbolic link to a file
  43 .Sh SYNOPSIS
  44 .Fd #include <unistd.h>
  45 .Ft int
  46 .Fo symlink
  47 .Fa "const char *path1"
  48 .Fa "const char *path2"
  49 .Fc
  50 .Ft int
  51 .Fn symlinkat "const char *name1" "int fd" "const char *name2"
  52 .Sh DESCRIPTION
  53 A symbolic link
  54 .Fa path2
  55 is created to
  56 .Fa path1
  57 .Pf ( Fa path2
  58 is the name of the
  59 file created,
  60 .Fa path1
  61 is the string
  62 used in creating the symbolic link).
  63 Either name may be an arbitrary path name; the files need not
  64 be on the same file system.
  65 .Pp
  66 The
  67 .Fn symlinkat
  68 system call is equivalent to
  69 .Fn symlink
  70 except in the case where
  71 .Fa name2
  72 specifies a relative path.
  73 In this case the symbolic link is created relative to the directory
  74 associated with the file descriptor
  75 .Fa fd
  76 instead of the current working directory.
  77 If
  78 .Fn symlinkat
  79 is passed the special value
  80 .Dv AT_FDCWD
  81 in the
  82 .Fa fd
  83 parameter, the current working directory is used and the behavior is
  84 identical to a call to
  85 .Fn symlink .
  86 .Sh RETURN VALUES
  87 Upon successful completion, a zero value is returned.
  88 If an error occurs, the error code is stored in
  89 .Va errno
  90 and a -1 value is returned.
  91 .Sh ERRORS
  92 The symbolic link succeeds unless:
  93 .Bl -tag -width Er
  94 .\" ===========
  95 .It Bq Er EACCES
  96 Write permission is denied in the directory
  97 where the symbolic link is being created.
  98 .\" ===========
  99 .It Bq Er EACCES
 100 A component of the
 101 .Fa path2
 102 path prefix denies search permission.
 103 .\" ===========
 104 .It Bq Er EDQUOT
 105 The directory in which the entry for the new symbolic link
 106 is being placed cannot be extended because the
 107 user's quota of disk blocks on the file system
 108 containing the directory has been exhausted.
 109 .\" ===========
 110 .It Bq Er EDQUOT
 111 The new symbolic link cannot be created because the user's
 112 quota of disk blocks on the file system that will
 113 contain the symbolic link has been exhausted.
 114 .\" ===========
 115 .It Bq Er EDQUOT
 116 The user's quota of inodes on the file system on
 117 which the symbolic link is being created has been exhausted.
 118 .\" ===========
 119 .It Bq Er EEXIST
 120 .Fa Path2
 121 already exists.
 122 .\" ===========
 123 .It Bq Er EFAULT
 124 .Fa Path1
 125 or
 126 .Fa path2
 127 points outside the process's allocated address space.
 128 .\" ===========
 129 .It Bq Er EIO
 130 An I/O error occurs while making the directory entry
 131 or allocating the inode.
 132 .\" ===========
 133 .It Bq Er EIO
 134 An I/O error occurs while making the directory entry for
 135 .Fa path2 ,
 136 or allocating the inode for
 137 .Fa path2 ,
 138 or writing out the link contents of
 139 .Fa path2 .
 140 .\" ===========
 141 .It Bq Er ELOOP
 142 Too many symbolic links are encountered in translating the pathname.
 143 This is taken to be indicative of a looping symbolic link.
 144 .\" ===========
 145 .It Bq Er ENAMETOOLONG
 146 A component of a pathname exceeds
 147 .Dv {NAME_MAX}
 148 characters, or an entire path name exceeds
 149 .Dv {PATH_MAX}
 150 characters.
 151 .\" ===========
 152 .It Bq Er ENOENT
 153 A component of
 154 .Fa path2
 155 does not name an existing file or
 156 .Fa path2
 157 is an empty string.
 158 .\" ===========
 159 .It Bq Er ENOSPC
 160 The directory in which the entry for the new symbolic link is being placed
 161 cannot be extended because there is no space left on the file
 162 system containing the directory.
 163 .\" ===========
 164 .It Bq Er ENOSPC
 165 The new symbolic link cannot be created because there
 166 there is no space left on the file
 167 system that will contain the symbolic link.
 168 .\" ===========
 169 .It Bq Er ENOSPC
 170 There are no free inodes on the file system on which the
 171 symbolic link is being created.
 172 .\" ===========
 173 .It Bq Er ENOTDIR
 174 A component of the
 175 .Fa path2
 176 prefix is not a directory.
 177 .\" ===========
 178 .It Bq Er EROFS
 179 The file
 180 .Fa path2
 181 would reside on a read-only file system.
 182 .El
 183 .Pp
 184 In addition to the errors returned by the
 185 .Fn symlink ,
 186 the
 187 .Fn symlinkat
 188 may fail if:
 189 .Bl -tag -width Er
 190 .It Bq Er EBADF
 191 The
 192 .Fa name2
 193 argument does not specify an absolute path and the
 194 .Fa fd
 195 argument is neither
 196 .Dv AT_FDCWD
 197 nor a valid file descriptor open for searching.
 198 .It Bq Er ENOTDIR
 199 The
 200 .Fa name2
 201 argument is not an absolute path and
 202 .Fa fd
 203 is neither
 204 .Dv AT_FDCWD
 205 nor a file descriptor associated with a directory.
 206 .El
 207 .Sh SEE ALSO
 208 .Xr ln 1 ,
 209 .Xr link 2 ,
 210 .Xr unlink 2 ,
 211 .Xr symlink 7
 212 .Sh STANDARDS
 213 The
 214 .Fn symlinkat
 215 system call is expected to conform to POSIX.1-2008 .
 216 .Sh HISTORY
 217 The
 218 .Fn symlink
 219 function call appeared in
 220 .Bx 4.2 .
 221 The
 222 .Fn symlinkat
 223 system call appeared in OS X 10.10