man2/symlink.2

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   4 .\"                               1993 Michael Haardt, Ian Jackson.
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  26 .\" Modified 1993-07-24 by Rik Faith
  27 .\" Modified 1996-04-26 by Nick Duffek <nsd@bbc.com>
  28 .\" Modified 1996-11-06 by Eric S. Raymond <esr@thyrsus.com>
  29 .\" Modified 1997-01-31 by Eric S. Raymond <esr@thyrsus.com>
  30 .\" Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
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  32 .TH SYMLINK 2 2004-06-23 "Linux 2.6.7" "Linux Programmer's Manual"
  33 .SH NAME
  34 symlink \- make a new name for a file
  35 .SH SYNOPSIS
  36 .B #include <unistd.h>
  37 .sp
  38 .BI "int symlink(const char *" oldpath ", const char *" newpath );
  39 .SH DESCRIPTION
  40 .BR symlink ()
  41 creates a symbolic link named
  42 .I newpath
  43 which contains the string
  44 .IR oldpath .
  45
  46 Symbolic links are interpreted at run-time as if the contents of the
  47 link had been substituted into the path being followed to find a file or
  48 directory.
  49
  50 Symbolic links may contain
  51 .I ..
  52 path components, which (if used at the start of the link) refer to the
  53 parent directories of that in which the link resides.
  54
  55 A symbolic link (also known as a soft link) may point to an existing
  56 file or to a nonexistent one; the latter case is known as a dangling
  57 link.
  58
  59 The permissions of a symbolic link are irrelevant; the ownership is
  60 ignored when following the link, but is checked when removal or
  61 renaming of the link is requested and the link is in a directory with
  62 the sticky bit
  63 .RB ( S_ISVTX )
  64 set.
  65
  66 If
  67 .I newpath
  68 exists it will
  69 .I not
  70 be overwritten.
  71 .SH "RETURN VALUE"
  72 On success, zero is returned.
  73 On error, \-1 is returned, and
  74 .I errno
  75 is set appropriately.
  76 .SH ERRORS
  77 .TP
  78 .B EACCES
  79 Write access to the directory containing
  80 .I newpath
  81 is denied, or one of the directories in the path prefix of
  82 .IR newpath
  83 did not allow search permission.
  84 (See also
  85 .BR path_resolution (2).)
  86 .TP
  87 .B EEXIST
  88 .I newpath
  89 already exists.
  90 .TP
  91 .B EFAULT
  92 .IR oldpath " or " newpath " points outside your accessible address space."
  93 .TP
  94 .B EIO
  95 An I/O error occurred.
  96 .TP
  97 .B ELOOP
  98 Too many symbolic links were encountered in resolving
  99 .IR newpath .
 100 .TP
 101 .B ENAMETOOLONG
 102 .IR oldpath " or " newpath " was too long."
 103 .TP
 104 .B ENOENT
 105 A directory component in
 106 .I newpath
 107 does not exist or is a dangling symbolic link, or
 108 .I oldpath
 109 is the empty string.
 110 .TP
 111 .B ENOMEM
 112 Insufficient kernel memory was available.
 113 .TP
 114 .B ENOSPC
 115 The device containing the file has no room for the new directory
 116 entry.
 117 .TP
 118 .B ENOTDIR
 119 A component used as a directory in
 120 .IR newpath
 121 is not, in fact, a directory.
 122 .TP
 123 .B EPERM
 124 The filesystem containing
 125 .IR newpath
 126 does not support the creation of symbolic links.
 127 .TP
 128 .B EROFS
 129 .I newpath
 130 is on a read-only filesystem.
 131 .SH "CONFORMING TO"
 132 SVr4, 4.3BSD, POSIX.1-2001.
 133 .\" SVr4 documents additional error codes EDQUOT and ENOSYS.
 134 .\" See
 135 .\" .BR open (2)
 136 .\" re multiple files with the same name, and NFS.
 137 .SH NOTES
 138 No checking of
 139 .I oldpath
 140 is done.
 141
 142 Deleting the name referred to by a symlink will actually delete the
 143 file (unless it also has other hard links).
 144 If this behaviour is not desired, use
 145 .BR link (2).
 146 .SH "SEE ALSO"
 147 .BR ln (1),
 148 .BR link (2),
 149 .BR lstat (2),
 150 .BR open (2),
 151 .BR path_resolution (2),
 152 .BR readlink (2),
 153 .BR rename (2),
 154 .BR symlinkat (2),
 155 .BR unlink (2)