Parsing command line input from STDIN

TStanley has asked for the wisdom of the Perl Monks concerning the following question:

I am writing a shell script to get the status of the logical volumes on an HP server. The command that I am using is lvdisplay, and it produces the following output:

$ lvdisplay /dev/vg00/lvol3
--- Logical volumes ---
LV Name                     /dev/vg00/lvol3
VG Name                     /dev/vg00
LV Permission               read/write
LV Status                   available/syncd
Mirror copies               1
Consistency Recovery        MWC
Schedule                    parallel
LV Size (Mbytes)            200
Current LE                  50
Allocated PE                100
Stripes                     0
Stripe Size (Kbytes)        0
Bad block                   off
Allocation                  strict/contiguous
IO Timeout (Seconds)        default
[download]

The above is more info than I really need. What I would like to get this to look like is the following:

LV Name                     /dev/vg00/lvol3
LV Status                   available/syncd
Mirror copies               1
[download]

My attempt at this is to pipe the output of the lvdisplay into a perl command line program as follows:

lvdisplay /dev/vg00/lvol3 |perl -a -n -F'\n' -e'print "$F[1]\n$F[4]\n$
+F[5]\n";'
[download]

Any ideas as to how I might accomplish this?

TStanley
--------
The only thing necessary for the triumph of evil is for good men to do nothing -- Edmund Burke

Comment on Parsing command line input from STDIN Select or Download Code

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Re: Parsing command line input from STDIN by broquaint (Abbot) on Dec 19, 2003 at 14:01 UTC
If you're field names are going to stay static then this should do the trick `lvdisplay /dev/vg00/lvol3 \| \ perl -ne 'print if /LV (Name\|Status)\|Mirror/'` [download] HTH `_________ broquaint`	[reply] [d/l]
Re: Re: Parsing command line input from STDIN by TStanley (Canon) on Dec 19, 2003 at 14:08 UTC
That did the trick. Thanks for the help. :-D TStanley -------- The only thing necessary for the triumph of evil is for good men to do nothing -- Edmund Burke	[reply]
Re: Parsing command line input from STDIN by thospel (Hermit) on Dec 19, 2003 at 16:33 UTC
Broqaints answer is of course the proper one, but in case you really wanted to select numbered lines, you can use an impossible output character to slurp all: `lvdisplay /dev/vg00/lvol3 \| perl -ln0aF'\n' -e 'print for @F[1,4,5]'` [download] (or use -0777 if there are no impossible output characters). Golfers (sorry, I can't resist) might write: `lvdisplay /dev/vg00/lvol3 \| perl -lp0aF'\n' -e '}for(@F[1,4,5]){' lvdisplay /dev/vg00/lvol3 \| perl -n0aF/^/m -e 'print@F[1,4,5]'` [download] Or select on line-number, e.g.: `lvdisplay /dev/vg00/lvol3 \| perl -ne 'print if $.=~/^(2\|5\|6)$/'` [download] Golfers would of course write that as: `lvdisplay /dev/vg00/lvol3 \| perl -pe '$_ x=$.=~/^[256]/' lvdisplay /dev/vg00/lvol3 \| perl -pe '$_ x=256=~$.' lvdisplay /dev/vg00/lvol3 \| perl -pe '$_ x=$^H=~$.'` [download] (use a real control-H in the last one for a one char gain)	[reply] [d/l] [select]
Re: Parsing command line input from STDIN by gt8073a (Hermit) on Dec 19, 2003 at 22:17 UTC
I am writing a shell script to... `lvdisplay /dev/vg00/lvol3 \| grep -P "LV (Name\|Status)\|Mirror"` [download] Still Perl, I suppose. Will perl for money JJ Knitis	[reply] [d/l]