meaning of today=${1:-${today}} Post: 302612715

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Top Forums Shell Programming and Scripting meaning of today=${1:-${today}} Post 302612715 by Vidhyaprakash on Monday 26th of March 2012 09:35:14 AM

03-26-2012

Registered User

meaning of today=${1:-${today}}

what does today=${1:-${today}} mean???

I saw a script which has these two lines:
today=`date '+%y%m%d'`
today=${1:-${today}}

but both gives the same value for $today

Code:

user:/export/home/user>today=`date '+%y%m%d'`
user:/export/home/user>echo $today
120326
user:/export/home/user>today=${1:-${today}}
user:/export/home/user>echo $today
120326
user:/export/home/user>today=
user:/export/home/user>today=${1:-${today}}
user:/export/home/user>echo $today
 
user:/export/home/user>

Can someone please let me know, what actually today=${1:-${today}}
means???

Vidhyaprakash

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vfs_readonly

VFS_READONLY(8) 					    System Administration tools 					   VFS_READONLY(8)

NAME

       vfs_readonly - make a Samba share read only for a specified time period

SYNOPSIS

       vfs objects = readonly

DESCRIPTION

       This VFS module is part of the samba(7) suite.

       The vfs_readonly VFS module marks a share as read only for all clients connecting within the configured time period. Clients connecting
       during this time will be denied write access to all files in the share, irrespective of ther actual access privileges.

       This module is stackable.

OPTIONS

       readonly:period = BEGIN, END
	   Only mark the share as read only if the client connection was made between the times marked by the BEGIN and END date specifiers. The
	   syntax of these date specifiers is the same as that accepted by the -d option of GNU date(1).

EXAMPLES

       Mark all shares read only:

		   [global]
		vfs objects = readonly

       Mark the [backup] share as read only during business hours:

		   [backup]
		path = /readonly
		vfs objects = readonly
		readonly:period = readonly:period = "today 9:00","today 17:00"

VERSION

       This man page is correct for version 3.0.25 of the Samba suite.

AUTHOR

       The original Samba software and related utilities were created by Andrew Tridgell. Samba is now developed by the Samba Team as an Open
       Source project similar to the way the Linux kernel is developed.

Samba 3.5							    06/18/2010							   VFS_READONLY(8)