Shell Programming and Scripting

#!/usr/bin/perl -w
print "Please Enter the VG name to be checked:";
$A = <>;
print "Please Enter the free size to be checked in GB:";
$B = <>;
        $vgcheck = `vgdisplay -v 2> /dev/null |grep -i "vg name" |grep -i $A`;
        $vgcheckc = `echo "$vgcheck" |wc -c`;
        print "$vgcheckc";
        if ($vgcheckc > 0)
                {
                $FREE = `vgdisplay $A | grep -i 'Free PE' | awk '{print $NF}'`;
                print $FREE;
                $PESIZE = `vgdisplay $A |grep -i 'PE Size' |awk '{print $NF}'`;
                print $PESIZE
                $total = $FREE * $PESIZE;
                $check = $B * 1024;
                        if ($total > $check)
                        {
                        print "Required Free Space is there in VG $A.. Please proceed to extend the Filesystem as requested\n";
                        print "TOtal free Space in VG $A is : $total MB";
                        }
                        else
                        {
                        print "Required Free Space is NOT there in VG $A..New LUNS are needed. CR must be raised \n";
                        print "Total free Space in VG $A is : $total MB\n";
                        $diff = $check - $total;
                        print "$diff MB of lun must be added to vg $A to proceed with Filesystem Extension\n";
                        }
                }
        else
                {
                print "Please give the correct VG name. The given VG is either not present nor It is NOT Activated\n";

$FREE = `vgdisplay $A | grep -i 'Free PE' | awk '{print $NF}'`;

$ perl testperl.pl
Please Enter the VG name to be checked:vgesar
Please Enter the free size to be checked in GB:20
41
Use of uninitialized value in concatenation (.) or string at testperl.pl line 11, <> line 2.
sh[2]: Syntax error at line 2 : `|' is not expected.
--- Volume groups ---
VG Name                     /dev/vgesar
VG Write Access             read/write
VG Status                   available, exclusive
Max LV                      255
Cur LV                      1
Open LV                     1
Max PV                      100
Cur PV                      2
Act PV                      2
Max PE per PV               1599
VGDA                        4
PE Size (Mbytes)            32
Total PE                    3198
Alloc PE                    3129
Free PE                     69
Total PVG                   0
Total Spare PVs             0
Total Spare PVs in use      0

Use of uninitialized value in concatenation (.) or string at testperl.pl line 13, <> line 2.
sh[2]: Syntax error at line 2 : `|' is not expected.
Argument "--- Volume groups ---\nVG Name                     /dev/..." isn't numeric in multiplication (*) at testperl.pl line 14, <> line 2.
Argument "--- Volume groups ---\nVG Name                     /dev/..." isn't numeric in multiplication (*) at testperl.pl line 14, <> line 2.

$ vgdisplay vgesar | grep -i 'Free PE' | awk '{print $NF}'
69

$ vgdisplay vgesar
--- Volume groups ---
VG Name                     /dev/vgesar
VG Write Access             read/write
VG Status                   available, exclusive
Max LV                      255
Cur LV                      1
Open LV                     1
Max PV                      100
Cur PV                      2
Act PV                      2
Max PE per PV               1599
VGDA                        4
PE Size (Mbytes)            32
Total PE                    3198
Alloc PE                    3129
Free PE                     69
Total PVG                   0
Total Spare PVs             0
Total Spare PVs in use      0

$ NF=slartibartfast
$ echo '{ $NF }'
{ $NF }
$ echo "'{ $NF }'"
{ slartibartfast }
$

#!/bin/sh

printf "Please Enter the VG name to be checked: "
read VOL

printf "Please Enter the free size to be checked in GB: "
read SIZE

vgdisplay "$VOL" 2> /dev/null | awk -v VOL="$VOL" -v SIZE="$SIZE" '
        # Capture the last field of these two lines
        /Free PE/       { FREE=$NF; }
        /PE Size/       { PE=$NF; }
END {   if( (!FREE) || (!PE) )
        {
                print VOL, "does not exist"
                exit
        }

        # Get EXACTLY how many PE is needed.
        NEEDPE=sprintf("%d", ((SIZE*1024)/PE) );
        # .000001 more means we need a whole extra PE.
        if( (SIZE * 1024) - (NEEDPE*PE) > 0) NEEDPE++;

        if(NEEDPE <= FREE)
                printf("%s has enough, %f GB needs %d/%d free PE\n", VOL, SIZE, NEEDPE, FREE);
        else    printf("%s has %d PE, %d more are needed\n", VOL, FREE, NEEDPE-FREE);
}'

$ vgdisplay vgesar | grep -i 'Free PE' | awk '{print $NF}'
69

A=vgesar
FREE=`vgdisplay vgesar | grep -i 'Free PE' | awk '{print $NF}'`
echo $FREE