Powershell Megathread: Verb-Noun Scripting is the future

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > Powershell Megathread: Verb-Noun Scripting is the future

KS: Jun 10, 2003; Outrageous Lumpwad

I have what I think is a very basic question. For commands that return data tables like this:

adaz posted:

pre:

HostName   DisplayName      EntryDate            Usages
compy1      blahblah         1/1/1000             10000
compy2      blahblah         1/1/1000             10000
compy3      foobar           1/1/1000             10000
compy4      snafu            1/1/1000             10000
compy5      foobar           1/1/1000             10000
compy6      foobar           1/1/1000             10000

How should I be scraping arbitrary data out of it? For instance, if I know I want the last row? Or just the hostname value from the last row? I know how to use | where and match a regex, but I am more interested in how it should be done when the data in the fields isn't known.

Edit: finally answered my own question reading about manipulating objects. select-object is what I needed.

KS fucked around with this message at 07:11 on Aug 23, 2011

# ¿ Aug 23, 2011 06:09

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# ¿ Apr 30, 2024 15:37

KS: Jun 10, 2003; Outrageous Lumpwad

adaz posted:

There are a lot of different ways of doing it ... Is any of that any help?

Thanks so much for the effort you put into this. I found the specific tool I needed and found a toolbox full of other useful things to boot.

Another question: I think I have a pretty good grasp on handling errors and building logic into a script to handle failures. However, yesterday I had one script simply hang -- it didn't error out, but one of the cmdlets in the script hung indefinitely. What are the methods for dealing with this mode of failure?

# ¿ Sep 6, 2011 18:53

KS: Jun 10, 2003; Outrageous Lumpwad

So I'm a rank beginner at this and I'm embarrassed to post this snip. When a SAN-based snapshot is presented to a different server, it shows up with some flags set on the volumes. I am trying to enumerate those volumes and generate a diskpart script to unset the flags.

code:

$diskpart = diskpart /s diskpartlist.txt | Select-String -pattern "Hidden"

$a = $diskpart[0]
$a = $a.tostring()
$a = $a.substring(2,13)
$a = "select $a"

$b = $diskpart[1]
$b = $b.tostring()
$b = $b.substring(2,13)
$b = "select $b"


write-output $a "att vol clear readonly" "att vol clear hidden" "att vol clear shadowcopy" $b 
`"att vol clear readonly" "att vol clear hidden" "att vol clear shadowcopy" | out-file diskpart.txt

diskpart /s diskpart.txt

The content of diskpartlist.txt is just "list volume" The above generates a file that can be fed into diskpart that looks like:

code:

select volume 3
att vol clear readonly
att vol clear hidden
att vol clear shadowcopy
select volume 7
att vol clear readonly
att vol clear hidden
att vol clear shadowcopy

I ran into so many things I need to learn along the way with the format of the data and breaking it up into useful chunks: system objects vs. arrays vs. strings and the tools you can use for each. For instance, you can write "select $a" to a file and it works, but you cannot write "select $a.substring(2,13)"

I know it shouldn't be this hard, and I really want to learn how to do this better (and generalize it for result sets of indeterminate size). I just feel lost without awk and sed.

# ¿ Nov 10, 2011 22:50

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