Content-type: text/html Man page of symlink

symlink

Section: System Calls (2)
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NAME

symlink - Makes a symbolic link to a file  

SYNOPSIS

#include <unistd.h>

int symlink (        const char *path1,
       const char *path2 );
 

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

symlink(): XPG4-UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags.  

PARAMETERS

Specifies the contents of the symbolic link to create. Names the symbolic link to be created.  

DESCRIPTION

The symlink() function creates a symbolic link with the name specified by the path2 parameter which refers to the file named by the path1 parameter.

Like a hard link (described in the link() function), a symbolic link allows a file to have multiple names. The presence of a hard link guarantees the existence of a file, even after the original name has been removed. A symbolic link provides no such assurance; in fact, the file named by the path1 parameter need not exist when the link is created. Unlike hard links, a symbolic link can cross file system boundaries.

When a component of a pathname refers to a symbolic link rather than a directory, the pathname contained in the symbolic link is resolved. If the pathname in the symbolic link starts with a / (slash), the symbolic link pathname is resolved relative to the process root directory. If the pathname in the symbolic link does not start with a / (slash), the symbolic link pathname is resolved relative to the directory that contains the symbolic link.

If the symbolic link is the last component of the original pathname, remaining components of the original pathname are appended to the contents of the link and pathname resolution continues.

The symbolic link pathname may or may not be traversed, depending on which function is being performed. Most functions traverse the link.

The functions which refer only to the symbolic link itself, rather than to the object to which the link refers, are: An error is returned if a symbolic link is named by the path2 parameter. If the file specified is a symbolic link, the status of the link itself is returned. An error is returned if a symbolic link is named as the path parameter. This call applies only to symbolic links. A symbolic link can be removed by invoking the remove() function. If the file to be renamed is a symbolic link, the symbolic link is renamed. If the new name refers to an existing symbolic link, the symbolic link is destroyed. An error is returned if a symbolic link is named as the path parameter. An error is returned if the symbolic link named by the path2 parameter already exists. A symbolic link can be created that refers to another symbolic link; that is, the path1 parameter can refer to a symbolic link. A symbolic link can be removed by invoking unlink().

Search access to the symbolic link is required to traverse the pathname contained therein. Normal permission checks are made on each component of the symbolic link pathname during its resolution.  

RETURN VALUES

Upon successful completion, the symlink() function returns a value of 0 (zero). If the symlink() function fails, a value of -1 is returned and errno is set to indicate the error.  

ERRORS

If the symlink() function fails, errno may be set to one of the following values: The requested operation requires writing in a directory with a mode that denies write permission, or search permission is denied on a component of path2. The directory in which the entry for the 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. The path specified by the path2 parameter already exists. Too many symbolic links are found in translating path2. The length of the path1 parameter or path2 parameter exceeds PATH_MAX, or a pathname component of path2 is longer than NAME_MAX while {_POSIX_NO_TRUNC} is in effect. The path2 parameter points to a null pathname, or a component of path2 does not exist. The directory in which the entry for the symbolic link is being placed cannot be extended because there is no space left on the file system containing the directory.

The new symbolic link cannot be created because there is no space left on the file system which would contain the link.
There are no free inodes on the file system on which the file is being created. The operation is not applicable for this file system type. A component of path2 is not a directory. The requested operation requires writing in a directory on a read-only file system. [Digital] For NFS file access, if the symlink() function fails, errno may also be set to one of the following values: Indicates either that the system file table is full, or that there are too many files currently open in the system. Indicates a stale NFS file handle. An opened file was deleted by the server or another client; a client cannot open a file because the server has unmounted or unexported the remote directory; or the directory that contains an opened file was either unmounted or unexported by the server.
 

RELATED INFORMATION

Functions: link(2), readlink(2), unlink(2)

Commands: ln(1)

Standards: standards(5) delim off


 

Index

NAME
SYNOPSIS
STANDARDS
PARAMETERS
DESCRIPTION
RETURN VALUES
ERRORS
RELATED INFORMATION

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Time: 02:40:17 GMT, October 02, 2010