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Top Forums Shell Programming and Scripting Special IF construct syntax in UNIX Post 302944795 by TomG on Friday 22nd of May 2015 03:52:11 AM
Old 05-22-2015
HP Special IF construct syntax in UNIX

Hi,

I don't understand && and || in this context. I thought && is for logical 'AND' and || is for logical 'OR'.

Code:
[ ! -z "$var" ] && echo "Not empty" || echo "Empty"

Please help


Thank You
 

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LVDISPLAY(8)						      System Manager's Manual						      LVDISPLAY(8)

NAME
lvdisplay - display attributes of a logical volume SYNOPSIS
lvdisplay [-c|--colon] [-d|--debug] [-h|-?|--help] [--ignorelockingfailure] [--maps] [-P|--partial] [-v|--verbose] LogicalVolumePath [Logi- calVolumePath...] DESCRIPTION
lvdisplay allows you to see the attributes of a logical volume like size, read/write status, snapshot information etc. lvs (8) is an alternative that provides the same information in the style of ps (1). lvs is recommended over lvdisplay. OPTIONS
See lvm for common options. -c, --colon Generate colon separated output for easier parsing in scripts or programs. N.B. lvs (8) provides considerably more control over the output. The values are: * logical volume name * volume group name * logical volume access * logical volume status * internal logical volume number * open count of logical volume * logical volume size in sectors * current logical extents associated to logical volume * allocated logical extents of logical volume * allocation policy of logical volume * read ahead sectors of logical volume * major device number of logical volume * minor device number of logical volume -m, --maps Display the mapping of logical extents to physical volumes and physical extents. Examples "lvdisplay -v /dev/vg00/lvol2" shows attributes of that logical volume. If snapshot logical volumes have been created for this original logical volume, this command shows a list of all snapshot logical volumes and their status (active or inactive) as well. "lvdisplay /dev/vg00/snapshot" shows the attributes of this snapshot logical volume and also which original logical volume it is associated with. SEE ALSO
lvm(8), lvcreate(8), lvscan(8) Sistina Software UK LVM TOOLS 2.02.44-cvs (02-17-09) LVDISPLAY(8)
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