Chromium Browser for Linus (Debian)

https://tutorials-raspberrypi.com/google-chrome-for-raspberry-pi/

sudo apt-get install chromium-browser --yes

Operates similarly to Chrome, but feels a bit faster, particularly on a Raspberry Pi.

Linux Powershell $PROFILE

One of my favorite things in Windows Powershell is the $PROFILE. I always refer to the How-To Geek article for creating it.

But what about $PROFILE in Linux Powershell?

PS /home/david> Test-Path $PROFILE
False
PS /home/david> New-Item -Path $PROFILE -Type File -Force

    Directory: /home/david/.config/powershell

Mode                LastWriteTime         Length Name
----                -------------         ------ ----
------          3/29/19  10:26 AM              0 Microsoft.PowerShell_profile.ps1

PS /home/david> $PROFILE
/home/david/.config/powershell/Microsoft.PowerShell_profile.ps1


That was easy, but what do we do with this?

Well, for one thing, I notice that my terminal while in Powershell is named "Untitled".

That's an easy fix:

PS /home/david> Set-Content -Path $PROFILE -Value '$Host.UI.RawUI.WindowTitle = "Powershell"'
PS /home/david> Get-Content $PROFILE
$Host.UI.RawUI.WindowTitle = "Powershell"
PS /home/david> .$PROFILE

Now it looks like a shell should:

You could also add a function, allowing you to rename the terminal on demand. Add to your $PROFILE in an editor:

function Rename-Shell{
    param([string]$Name)
    $Host.UI.RawUI.WindowTitle = $Name
}


Then reload your $PROFILE and add a new title:

PS /home/david> .$PROFILE
PS /home/david> Rename-Shell -Name 'My Terminal'


Your  $PROFILE loads every time you start Powershell and imports the contents. If you change the $PROFILE you can reload it by "dot sourcing" (the .$PROFILE mentioned above). You can set variables, create functions, assign aliases... $PROFILE is a Powershell script, so if you can script it, you can add it.

Linux Powershell Issues: History

So, my Mint system has Powershell. "Let's see how it works," I say.

david@mint ~ $ powershell
PowerShell 6.1.3

https://aka.ms/pscore6-docs
Type 'help' to get help.

PS /home/david> Get-Location
Error reading or writing history file '/home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt': Access to the path '/home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt' is denied.
ưm
Path
----
/home/david


Well, that's no good. It ran the Get-Location command, but I certainly don't want to see all that red every time I perform an action in the shell. Fortunately, the error shows us where our history file is.

david@mint ~ $ ls -l /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt
-rw-r--r-- 1 root root 336 Mar 28 11:04 /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt


Why does root own my history file? I installed Powershell as root, but that still seems odd. Well, there's no going back, so let's take over the file.

david@mint ~ $ sudo chown david /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt
[sudo] password for david:
david@mint ~ $ sudo chgrp david /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt
david@mint ~ $ ls -l /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt
-rw-r--r-- 1 david david 336 Mar 28 11:04 /home/david/.local/share/powershell/PSReadLine/ConsoleHost_history.txt


Now, back to the shell:

david@mint ~ $ powershell
PowerShell 6.1.3
Copyright (c) Microsoft Corporation. All rights reserved.

https://aka.ms/pscore6-docs
Type 'help' to get help.

PS /home/david> Get-Location

Path
----
/home/david

PS /home/david> Get-History

  Id CommandLine
  -- -----------
   1 Get-Location

Sha-Bang Your Scripts

Sometimes, Windows can be a friendly scripting environment. You write a batch file, and you run it. You write a Powershell script, and provided your Execution Policy allows it, you run it. If it is a batch file, you can even double-click it in the GUI. Powershell, however, you either need to run in its shell, or wrap it in a batch script. The bash shell works a bit differently.

The Sha-Bang (Sharp Bang) declares to the shell what is needed to execute the script. A bash script (example.sh) would normally look like:

#!/bin/sh
echo "Hello, World!"


You would then add the executable flag:

chmod +x example.sh

The same can be done with other interpreters, such as python or perl:

#!/usr/bin/env python
print("Hello, World!")


Or:

#!/usr/bin/perl -w
print "Hello, World!\n"


The same can be done with Powershell on linux, provided your shell knows where Powershell lives.

$ which powershell
/snap/bin/powershell


If you get a response, then Powershell is in your env PATH, so you can have:

#!/usr/bin/env powershell
Write-Host "Hello, World!"


Powershell users in Windows will note that just as running a local script, you need a dot-slash:

$ ./example.ps1
Hello, World!

Accessing JSON Data and Powershell Objects within Strings

Yesterday we discussed getting JSON data from a SqLite3 database.

Using that data in Powershell means turning it into an object. Referencing it often means working with strings.

First, lets get our data back, and then convert it to an object

PS A:\> $MyData = Get-Content $TempCsv | ConvertFrom-Csv | ConvertTo-Json
PS A:\> $MyJson = $MyData | ConvertFrom-Json
PS A:\> $MyJson

name            twitter        url
----            -------        ---
David           dbsteimle      rhymeswithtimely.blogspot.com
Commander Candy codingComander codingcommanders.com

I want to turn this data into usable HTML. I could use the ConvertTo-HTML command:

PS A:\> $MyJson | ConvertTo-Html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"

  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>HTML TABLE</title>
</head><body>
<table>
<colgroup><col/><col/><col/></colgroup>
<tr><th>name</th><th>twitter</th><th>url</th></tr>
<tr><td>David</td><td>dbsteimle</td><td>rhymeswithtimely.blogspot.com</td></tr>
<tr><td>Commander Candy</td><td>codingComander</td><td>codingcommanders.com</td></tr>
</table>
</body></html>

Which results in:

name	twitter	url
David	dbsteimle	rhymeswithtimely.blogspot.com
Commander Candy	codingComander	codingcommanders.com

Some of that data is for link generation, though. My users shouldn't have to cut and paste a URL from an HTML document. Instead, let's treat Powershell like it were PHP, and loop through our object and create a proper table.

PS A:\> $OutPut = $null
PS A:\> $Output += "<table>`n<tr>`n<th>Name</th>`n<th>Twitter</th>`n<th>URL</th>`n</tr>`n"
PS A:\>
PS A:\> foreach($Record in $MyJson){
>> $OutPut += "<tr>`n"
>> $OutPut += "<th>$($Record.name)</th>`n"
>> $Output += "<td><a href='https://twitter.com/$($Record.twitter)'>@$($Record.twitter)</a></td>`n"
>> $Output += "<td><a href='http://$($Record.url)'>$($Record.url)</a></td>`n"
>> $OutPut += "</tr>`n"
>> }
PS A:\> $OutPut += "</table>"
PS A:\> $OutPut
<table>
<tr>
<th>Name</th>
<th>Twitter</th>
<th>URL</th>
</tr>
<tr>
<th>David</th>
<th><a href='https://twitter.com/dbsteimle'>@dbsteimle</a></th>
<th><a href='http://rhymeswithtimely.blogspot.com'>rhymeswithtimely.blogspot.com</a></th>
</tr>
<tr>
<th>Commander Candy</th>
<th><a href='https://twitter.com/codingComander'>@codingComander</a></th>
<th><a href='http://codingcommanders.com'>codingcommanders.com</a></th>
</tr>
</table>

Since $Record has properties we want to reference withing a string, we need to isolate it, as in $($Record.name) to allow the .name to parse properly.

Now, our resultant table has both twitter and webpage links, making the HTML more useful for our readers.

Name	Twitter	URL
David	@dbsteimle	rhymeswithtimely.blogspot.com
Commander Candy	@codingComander	codingcommanders.com

Sqlite3 Export to JSON

I create custom scripted Detection Methods for SCCM utilizing JSON. Powershell handles JSON nicely, particularly if converting from an object. Powershell will do the necessary escaping of characters, which can be missed when manually creating JSON, or when you know there will be many characters to escape. For example, here is some data which would need escaping, and its resultant JSON:

PS A:\> $Example = @"
>> localpath,registry,share,text
>> C:\Temp,HKLM:\SOFTWARE,\\thatshare\me,use a`ttab
>> "@
PS A:\> $Example
localpath,registry,share,text
C:\Temp,HKLM:\SOFTWARE,\\thatshare\me,use a     tab
PS A:\> $Example | ConvertFrom-Csv | ConvertTo-Json
{
    "localpath":  "C:\\Temp",
    "registry":  "HKLM:\\SOFTWARE",
    "share":  "\\\\thatshare\\me",
    "text":  "use a\ttab"
}

My Detection Methods will often look for file checksums, which means a path to the file and the expected checksum.To avoid mistakes, and to make it easier on me, I create a SqLite3 database with the items for my JSON. Exporting from SqLite3 can be sent to a CSV file, and then parsed into JSON. A simple database example:

PS A:\> sqlite3 .\example.db
SQLite version 3.24.0 2018-06-04 19:24:41
Enter ".help" for usage hints.
sqlite> .mode line
sqlite> SELECT * FROM example;
   name = David
twitter = dbsteimle
    url = rhymeswithtimely.blogspot.com

   name = Commander Candy
twitter = codingComander
    url = codingcommanders.com
sqlite> .quit

Now, a new trick to me it utilizing temporary files. I am using the dot NET method, which is usable in Linux Powershell as well (your mileage may vary). You can create a temp file with [System.IO.Path]::GetTempFileName(). To use that file, you want to assign it to a variable.

PS A:\> $TempCsv = [System.IO.Path]::GetTempFileName()
PS A:\> $TempCsv
C:/Users/david/AppData/Local/Temp/tmp47AD.tmp

Next, because SqLite3 does not use \ character in its paths, we need to change them to /.

PS A:\> $TempCsv = $TempCsv.Replace("\","/")
PS A:\> $TempCsv
C:/Users/david/AppData/Local/Temp/tmp47AD.tmp

Now we can create our SQL commands. This could also be a file, but I will use a here-string instead.

PS A:\> $TempSql = @"
>> .headers on
>> .mode csv
>> .output $TempCsv
>> SELECT name,
>>        twitter,
>>        url
>> FROM example;
>> .quit
>> "@
PS A:\> $TempSql
.headers on
.mode csv
.output C:/Users/david/AppData/Local/Temp/tmp47AD.tmp
SELECT name,
       twitter,
       url
FROM example;
.quit

Notice our converted $TempCsv value is in the $TempSql here-string.

Now, pipe the $TempSql into SqLite3:

PS A:\> $TempSql | sqlite3 .\example.db

Our $TempCsv frile will now have the output from SqLite3 in CSV format.

PS A:\> gc $TempCsv
name,twitter,url
David,dbsteimle,rhymeswithtimely.blogspot.com
"Commander Candy",codingComander,codingcommanders.com

We can now use this CSV formatted data, but must convert it to a Powershell Object.

PS A:\> Get-Content $TempCsv | ConvertFrom-Csv | ConvertTo-Json
[
    {
        "name":  "David",
        "twitter":  "dbsteimle",
        "url":  "rhymeswithtimely.blogspot.com"
    },
    {
        "name":  "Commander Candy",
        "twitter":  "codingComander",
        "url":  "codingcommanders.com"
    }
]

Powershell on Linux

Process from https://websiteforstudents.com/install-microsoft-powershell-core-for-linux-on-ubuntu-16-04-18-04/

The only process that worked for me, however, was the snapd approach:

sudo apt update
sudo apt install snapd
sudo snap install powershell --classic


One issue, though, is that I must sudo powershell to launch.

EDIT: to use powershell as a normal user, with the snap install, you need to add /snap/bin to your path

david@mybox ~ $ sudo which pwsh
/snap/bin/pwsh
david@mybox ~ $ PATH=$PATH:/snap/bin

---

Distributor ID: LinuxMint
Description: Linux Mint 18.3 Sylvia
Release: 18.3
Codename: sylvia

Name                           Value
----                           -----
PSVersion                      6.1.3
PSEdition                      Core
GitCommitId                    6.1.3
OS                             Linux 4.15.0-46-generic #49~16.04.1-Ubuntu SMP Tue Feb 12 17:45:24 UTC 2019
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0