powershell
- I'd really rather not do this, but I can't find a safe and seen-to-be-safe way of doing what I want to do through PowerShell or any other automated tool ↩
-
The ‘better way’ is to use
gci -force. That includes all the system databases. ↩︎ - one should test one’s code
- if you put something invalid in a ‘select’ list in Powershell it won’t necessarily error
how to rdp to several desktops one after the other
For reasons that aren’t necessarily relevant, I wanted to use Remote Desktop to visit a list of servers1. I tried doing this:
foreach ($S in "server01", "server02, "server03") {
mstsc /f /V:$S
}
This works….but it immediately starts rdp sessions to each of the servers. This is fine in this example, where there are only 3 servers, but in real life I’ve got a list of twenty or so and I don’t really want to open 20-odd rdp sessions at once.
What I did instead to force it do the rdp’s sequentially was this:
foreach ($S in "server01", "server02, "server03") {
mstsc /f /V:$S
$ThrowAway = read-host "Hit Return"
}
how to extract tweets about...
This was the Powershell code I used to create the all the podcasts I’ve ever tweeted about post.
I downloaded the tweets from Twitter itself - I think there was a link somewhere within ‘Settings’
The .csv file looks like this:
So the code is:
$PodTweets = Import-Csv c:temptweets.csv | ? text -like "*podcast*"
$TweetsAsHtml = foreach ($P in $PodTweets)
{
# write-output $P.timestamp.Substring(0,10)
# Splitting the tweet text into words to allow for the processing of urls
$TweetTextAsArray = $P.text.split(" ")
$TextWithLink=""
foreach ($Word in $TweetTextAsArray)
{
if ($Word -like "http:*")
{
# if there is an expanded_url, then use that instead
if ($P.expanded_urls -ne "")
{
$Word = $P.expanded_urls
# for some reason the expanded url is sometimes repeated in the download
if ($Word -like "*,*")
{
$Word = $Word.split(",")[0]
}
}
# re-format the URL as a link
$Word = "`<a href=`"$Word`"`>$Word`<`/a`>"
}
$TextWithLink = "$TextWithLink$Word "
}
# create an object and output that
$properties = @{'TweetDate'=$P.timestamp.Substring(0,10);
'TweetText'=$TextWithLink}
$ReformattedTweets = New-Object -Type PSObject -Prop $properties
write-output $ReformattedTweets
}
$TweetsAsHtml | fl | out-file -encoding ascii -FilePath x.txt -width 1000
system databases not included in powershell sqlserver provider 'databases' folder
I hadn’t noticed this before.
If you do a dir listing of the databases for an instance within the Powershell Sqlserver provider, it doesn’t show the system databases
PS C:powershell> dir SQLSERVER:\SQL\my_pcinst2012\databases
Name Status Recovery Model CompatLvl Collation Owner
---- ------ -------------- --------- --------- -----
AdventureWorks2012 Normal Simple 110 SQL_Latin1_General_CP1_CI_AS matty
TSQL2012 Normal Full 110 Latin1_General_CI_AS matty
To get a listing for the system databases you can do the following. I would imagine there’s a better way (perhaps some equivalent to ls -a?)…but I can’t think of it at the minute1
PS C:powershell> foreach ($DB in ("master", "msdb", "model", "tempdb")) {gi SQLSERVER:\SQL\my_pcinst2012\databases\$DB }
Name Status Recovery Model CompatLvl Collation Owner
---- ------ -------------- --------- --------- -----
master Normal Simple 110 Latin1_General_CI_AS sa
msdb Normal Simple 110 Latin1_General_CI_AS sa
model Normal Simple 110 Latin1_General_CI_AS sa
tempdb Normal Simple 110 Latin1_General_CI_AS sa
Powershell pattern matching to check if a string is hex
I’ve been playing with pattern matching in Powershell.
I was trying to use ‘-match’ to ‘Check if the string is a hexadecimal number’ for the ‘Perl one-liners in Powershell’ page I’ve been working on.
I can’t pretend to entirely understand or explain pattern matching in Powershell, or in linux, but this seems to work.
$X = "21e" ; $Y = $X.length ; $X -match "[0123456789abcde]{$Y}"
This says match the string against ‘any combination of the characters within the square brackets (i.e. the hex digits) to the same length as the original string’.
So, the square brackets contain the allowable characters.
The curly brackets give the number of characters.
I tried just doing:
$X = "21e" ; $X -match "[0123456789abcde]{$X.length}"
…but this didn’t seem to work.
Tests
I tried the following strings - they all seemed to come up with the right answer: ``` $ $X = "21e" ; $Y = $X.length ; $X -match "[0123456789abcde]{$Y}" True $ $X = "21edjhsd" ; $Y = $X.length ; $X -match "[0123456789abcde]{$Y}" False $ $X = "21e34782348237847832748723" ; $Y = $X.length ; $X -match "[0123456789abcde]{$Y}" True $ $X = "21e34782348237847832748723f" ; $Y = $X.length ; $X -match "[0123456789abcde]{$Y}" False $ $X = "21e34782348237847832748723acbdaaa" ; $Y = $X.length ; $X -match "[0123456789abcde]{$Y}" True $ $X = " " ; $Y = $X.length ; $X -match "[0123456789abcde]{$Y}" False ```….although I’m not sure whether this is right or wrong:
$ $X = "" ; $Y = $X.length ; $X -match "[0123456789abcde]{$Y}"
True
Mis-spelling in Powershell
This was spectacularly incompetent even by my high standards of incompetence.
It illustrates that if you spell the name of a column incorrectly in Powershell, you don’t get an error, you just get a null column
get-wmiobject -class win32_operatingsystem -computer rdm016 |
select __Server, ServicePackMajorVerstion
And got:
__SERVER ServicePackMajorVerstion
-------- ------------------------
RDM016
I thought that no service packs had been applied. This, as more attentive readers will have spotted, was not the case. The null under ServicePackMajorVerstion is because you don’t spell ‘version’ with a ’t'. Two learnings from this:
How to report mp3 tags in Powershell
I’m slowly getting to grips with Powershell.
# -----------------------------------------------------------------
# Script - Catalog-MP3s.ps1 #
# Gets mp3 tags from the mp3 file.
# -----------------------------------------------------------------
# Parameter is either a directory or an individual mp3 Param ( $P_DIR_OR_MP3 )
# --------------------------
# Function: get-mp3info
# The function gets the tags
# for the specified mp3
# --------------------------
Function get-mp3info ($P_MP3)
{
# Get the tages into a variable
$TAGS = [TagLib.File]::Create("$P_MP3")
$TAGS_OBJECT = @{Filename = $TAGS.Name;
Bitrate = $TAGS.Properties.AudioBitRate;
Artist = $TAGS.tag.FirstArtist;
Title = $TAGS.tag.Title;
Genre = $TAGS.tag.FirstGenre;
LP = $TAGS.tag.Album}
# Output as an object
New-Object PSObject -Property $TAGS_OBJECT
}
# --------------------------
# Main body
# --------------------------
# Store the location of the taglib dll
$TAGLIB="C:\Users\Matt\Downloads\taglib-sharp-2.1.0.0-windows\taglib-sharp-2.1.0.0-windows\Libraries\tag\lib-sharp.dll"
# Load the DLL
[System.Reflection.Assembly]::LoadFile($Taglib)
# Get a list of all the MP3s under the specified folder
# - exclude anything that's not an mp3
# - Fullname contains the full path and filename
$MP3_LIST = gci -recurse Filesystem::$DIR_OR_MP3 |
where {$_.Extension -eq '.mp3'} |
select FullName
# Walk through the list, and output the tags
foreach ($MP3 in $MP3_LIST)
{
get-mp3info $MP3.Fullname
}
The heavily borrows from: