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Full Discussion: What is with the '&'.
Top Forums UNIX for Dummies Questions & Answers What is with the '&'. Post 17327 by peter.herlihy on Wednesday 13th of March 2002 03:10:09 PM
Old 03-13-2002
Another use of the ampersand "&" is to link commands in series..... typically best used as a double ampersand - which will only execute the subsequent commands if the preceeding one is successful

i.e.

cd /export/home/my_dir && ls -l && rm -i *old

This command will first change your directory - then list the contents - then remove files ending in 'old' (interactively prompting).

The difference of the double ampersand vs the single (cd /export/home/my_dir & ls -l & rm -i *old) is that if one of the preceeding commands failed (i.e there is no my_dir directory) then the subsequent command would still try to execute. With double when it fails the command doesn't try to do any more.

Maybe not related to your query re: directory or filenames - but will help to understand what it's useaeg can be.
 

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link(1) 						      General Commands Manual							   link(1)

NAME
link, unlink - Creates an additional directory entry for an existing file SYNOPSIS
link file1 file2 unlink file STANDARDS
Interfaces documented on this reference page conform to industry standards as follows: link: XCU5.0 unlink: XCU5.0 Refer to the standards(5) reference page for more information about industry standards and associated tags. DESCRIPTION
The link command performs the link() system call to create an additional directory entry for an existing file, file1. In effect, the underlying file then has two names, file1 and file2 (either of these arguments can be a pathname). The old and new entries share equal access rights to the underlying file. The unlink command performs the unlink() system call to remove a link to file created by link. The unlink command removes the directory entry specified by the file parameter and, if the entry is a hard link, decrements the link count of the file referenced by the link. You should be familiar with the link() and unlink() system calls before you use these commands. The link and unlink commands do not issue error messages when the associated system call is unsuccessful. NOTES
The link and unlink commands cannot be used to link and unlink directories. EXIT STATUS
The link and unlink commands both exit with the following: The link() or unlink() system call succeeded. Too few or too many arguments specified. The link() or unlink() system call failed. SEE ALSO
Commands: fsck(8), ln(1) Functions: link(2), unlink(2) link(1)
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