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
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  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 .B 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 .B ..
  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.  On error, \-1 is returned, and
  73 .I errno
  74 is set appropriately.
  75 .SH ERRORS
  76 .TP
  77 .B EACCES
  78 Write access to the directory containing
  79 .I newpath
  80 is denied, or one of the directories in the path prefix of
  81 .IR newpath
  82 did not allow search permission.
  83 (See also
  84 .BR path_resolution (2).)
  85 .TP
  86 .B EEXIST
  87 .I newpath
  88 already exists.
  89 .TP
  90 .B EFAULT
  91 .IR oldpath " or " newpath " points outside your accessible address space."
  92 .TP
  93 .B EIO
  94 An I/O error occurred.
  95 .TP
  96 .B ELOOP
  97 Too many symbolic links were encountered in resolving
  98 .IR newpath .
  99 .TP
 100 .B ENAMETOOLONG
 101 .IR oldpath " or " newpath " was too long."
 102 .TP
 103 .B ENOENT
 104 A directory component in
 105 .I newpath
 106 does not exist or is a dangling symbolic link, or
 107 .I oldpath
 108 is the empty string.
 109 .TP
 110 .B ENOMEM
 111 Insufficient kernel memory was available.
 112 .TP
 113 .B ENOSPC
 114 The device containing the file has no room for the new directory
 115 entry.
 116 .TP
 117 .B ENOTDIR
 118 A component used as a directory in
 119 .IR newpath
 120 is not, in fact, a directory.
 121 .TP
 122 .B EPERM
 123 The filesystem containing
 124 .IR newpath
 125 does not support the creation of symbolic links.
 126 .TP
 127 .B EROFS
 128 .I newpath
 129 is on a read-only filesystem.
 130 .SH NOTES
 131 No checking of
 132 .I oldpath
 133 is done.
 134
 135 Deleting the name referred to by a symlink will actually delete the
 136 file (unless it also has other hard links). If this behaviour is not
 137 desired, use
 138 .BR link .
 139 .SH "CONFORMING TO"
 140 SVr4, SVID, POSIX, BSD 4.3.  SVr4 documents additional error codes
 141 SVr4, SVID, BSD 4.3, X/OPEN.  SVr4 documents additional error codes
 142 EDQUOT and ENOSYS.
 143 See
 144 .BR open (2)
 145 re multiple files with the same name, and NFS.
 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 unlink (2)