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Full Discussion: [bash] Check if variable is set or blank
Top Forums Shell Programming and Scripting [bash] Check if variable is set or blank Post 302179659 by noratx on Friday 28th of March 2008 09:36:39 AM
Old 03-28-2008
[bash] Check if variable is set or blank
Hello guys.
In my script, i have the following code:
Code:
echo "The tarfile contains these directorys"
tar -tf file.tar > tarlist.txt
cat tarlist | awk -F/ '{print $1 "/" $2}' | nl
echo "Enter path of the directory you want to extract or just press enter to extract everything: "
read path
/usr/local/bin/gtar -xf file.tar $path

I need to check if the user gave a path to the script, or if he just pressed enter?
I know what to do between the 'THEN' and 'ELSE' statements.
I just need to know how to check if $path is really set or not.
 

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LEARN ABOUT MOJAVE

vfs-filesystems

vfs-filesystems(n)														vfs-filesystems(n)

__________________________________________________________________________________________________________________________________________________

NAME

       vfs-filesystems - Filesystems provided by tclvfs

SYNOPSIS

       package require Tcl  8.4

       package require vfs  ?1.2.1?

       package require vfs::zip  ?1.0?

       package require vfs::mk4  ?1.6?

       package require vfs::tar  ?0.9?

       package require vfs::ftp  ?1.0?

       package require vfs::ns	?1.0?

       package require vfs::webdav  ?0.1?

       package require vfs::http  ?0.5?

       package require vfs::urltype  ?1.0?

       vfs::zip::Mount path to

       vfs::mk4::Mount path to

       vfs::tar::Mount path to

       vfs::ftp::Mount path to

       vfs::ns::Mount path to

       vfs::webdav::Mount path to

       vfs::http::Mount path to

       vfs::urltype::Mount path to

_________________________________________________________________

DESCRIPTION

       The  package  vfs  provides  not  only  the means to implement a virtual filesystem at the tcl level, but also a number of ready to be used
       filesystems as well.

       Each of these filesystem exists as its own package, and can be accessed through package require vfs::NAME.  The whole set of these  virtual
       filesystems is known informally as 'vfslib'.

SUPPORTED VFS TYPES

       Currently  supported are ftp, tar, http, zip, mk4, ns, and webdav.  In addition there is the ability to mount any 'urltype' as a new direc-
       tory, provided an appropriate vfs is supported.	This means that you can treat urls based on the schemes ftp://,  http://  and  file://	as
       files.	To  do	this, simply evaluate the command vfs::urltype::Mount ftp for example.	Any access inside the new volume will result in an
       attempt to require a package through package require vfs::${type}, which must therefore exist, or errors will be thrown.  If  a	filesystem
       is loaded, use the associated command listed below to mount a source for that filesystem as a tcl directory.

       vfs::zip::Mount path to
	      Mount the zip file path as directory to.

       vfs::mk4::Mount path to
	      Mount the metakit database file file path as directory to.

       vfs::tar::Mount path to
	      Mount the tar file path as directory to.

       vfs::ftp::Mount path to
	      Mount the ftp url path as directory to.

       vfs::ns::Mount path to
	      Mount the tcl namespace path as directory to.

       vfs::webdav::Mount path to
	      Mount the webdav url path as directory to.

       vfs::http::Mount path to
	      Mount the http url path as directory to.

       vfs::urltype::Mount path to
	      Mount the url path, of type urltype as directory to.

LIMITATIONS

       Most of the vfs types listed above have not been very well debugged as yet.  Please test them!

SEE ALSO

       vfs, vfs-fsapi

KEYWORDS

       file, filesystem, ftp, http, metakit, namespace, tar, vfs, vfslib, webdav, zip

COPYRIGHT

       Copyright (c) 2001-2003 Vince Darley <vincentdarley@users.sourceforge.net>
       Copyright (c) 2003 Andreas Kupries <andreas_kupries@users.sourceforge.net>

Tcl-level Virtual Filesystems						1.0							vfs-filesystems(n)
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