How to compile a C++ program on Mac OSX

File "HelloWorld.cpp" contents between the dashed lines:

-----

#include <iostream>

using namespace std;

int main()

{

    cout << "Hello world!" << endl;

    cout << "Hello again!" << endl;

    return 0;

}

-----

Now compile the program:

g++ HelloWorld.cpp -o HelloWorld

Now run the program:

./HelloWorld

My .vimrc customizations on OS X (MacOS)

I have bits and pieces of this scattered throughout this blog.  This is an effort to put it into one place. Don't be surprised if I add more to this post later.

Helpful customizations for .vimrc:

" This turns off the annoying bell every time I hit the wrong key
set visualbell

" The following two lines turn on syntax highlighting
filetype plugin indent on
syntax on

" This tells vim that I am using a black background and need light colored text
set background=dark

Git - remotes

git clone <remote_location> <clone_name> - Create a duplicate (clone) of remote_location and locally call it clone_name

git remote -v - Display a list of Git project remotes

git fetch - Bring changes in remote master down to origin/master branch (not my local master branch)

git merge origin/master - Bring changes in origin/master branch into my local master branch


Workflow:
- Fetch and merge changes from remote
git fetch
git merge origin/master
- Create branch to work on new stuff
git branch <my_new_branch>
- Work on stuff in my branch and then commit work
git checkout <my_new_branch>
vi mychange.txt
git add mychange.txt
git commit -m "My message"
- Fetch and merge from remote again
git fetch
git merge origin/master
- Push my branch up to the remote for review
git push origin <my_new_branch>

[Edit]

The excellent Mark Moser suggests the following shortcut:

git pull

Instead of:

git fetch
git merge origin/master

[/Edit]

Git - branches

git branch - Which branch am I on?

git branch <new_branch> - Create a new branch

git checkout <branch_name> - Switch to different branch

git merge <branch_name> - Merge branch_name into my current branch?

git branch -d <branch_name> - Delete the branch no longer needed

Git refresher

git init - Initializes my directory for a Git project

Git project has three parts:
1 - Working Directory - Where I create, edit, delete, and organize files
2 - Staging Area - Where I list changes I make to the working directory
3 - Repository - Where Git permanently stores those changes as different versions of the project

git status - Check status of changed files

git add filename - Adds file to Git project so Git watches for changes
git add filename1 filename2 - Add multiple files to Git project

git diff filename - Identifies changes within the file

git commit -m "Message describing commit"

git log - View log of commits

git show HEAD - Displays the message for the HEAD commit plus all the file changes that were committed.
HEAD = The commit I am currently on

git checkout HEAD filename - Revert filename back to the HEAD commit

git reset HEAD filename - Unstage (reset) filename from staging area.
Useful for when I accidentally added a file to the staging area and do not want to commit it.

get reset <SHA> - Rewind back to commit identified by SHA value.  SHA value is first 7 characters.
SHA values can be seen in the git log (use "git log" to view)

Powershell - Read SQL Log

Import-Module SQLPS -DisableNameChecking

$server = New-Object -TypeName Microsoft.SqlServer.Management.Smo.Server -ArgumentList "serverName"

# ReadErrorLog() returns a dataTable object
$d = $server.ReadErrorLog()

foreach ($r in $d.Rows)
{

    Write-Host "============================"
    Foreach ($c in $d.Columns)
    {
        Write-Host $c.ColumnName "=" $r[$c]

    }

}

---

ReadErrorLog(#)

If you provide a number, it reads that particular SQL log number.  (Eg - SQL log numbers 1 through 6).

PowerShell - Send Email

# Send email
Send-MailMessage -SmtpServer "smtp.corp.org" -to "you@yourcorp.net" -from "powershell@hostname.domain.corp.org" -subject "Test PowerShell email 1" -body "This is my body"

# Send email with an attachment
$body = "This is the long-winded message."
$file = "c:\temp\file.txt"

Send-MailMessage -SmtpServer "smtp.corp.org" -to "you@yourcorp.net" -from "powershell@hostname.domain.corp.org" -subject "Test PowerShell email 2" -body $body -Attachments $file

PowerShell - Read the Event Log

# Retrieve ten most recent events in the system log
Get-EventLog -LogName System -Newest 10 -ComputerName "changeme"

# Retrieve entries from today
Get-EventLog -LogName System -ComputerName "changeme" -After ( [datetime]::Today )

# Retrieve entries from today and yesterday
Get-EventLog -LogName System -ComputerName "changeme" -After ( [datetime]::Today.AddDays(-1) )

# Another way
$time = [datetime]::Today.AddDays(-1)
Get-WinEvent –FilterHashtable @{logname=’system’; starttime=$time } –MaxEvents 10 -ComputerName "changeme"

# Now store events in an array

$time = [datetime]::Today.AddDays(-1)
$array = Get-WinEvent –FilterHashtable @{logname=’system’,'application'; starttime=$time } –MaxEvents 50 -ComputerName "changeme" 

Write-Host $('-' * 70)

# Display the first five events captured
$array[1..5]

PowerShell - Read and Write Text Files

# Write, append, and read files

# First set up some variables
$filename = "c:\temp\file.txt"
$myText = "Hello World"
$mySecondLine = "Goodbye World"
$myThirdLine = "My third line"
$myFourthLine = "My fourth line"

# Create file
$myText > $filename

# Another way
$myText | Set-Content $filename

# Another way
$myText | Out-File $filename

#################################

# Append to file
$mySecondLine >> $filename

# Another way
$myThirdLine | Add-Content $filename

# Another way
$myFourthLine | Out-File $filename -Append

#################################

# Read content

$myVar = Get-Content $filename

# Dashes
Write-Host $('-' * 70)

# Display content
$myVar

# Display first line
Write-Host $('-' * 70)
$myVar[0]

# Display second line
Write-Host $('-' * 70)
$myVar[1]

# Display first three lines
Write-Host $('-' * 70)
$myVar[0..2]

# Display the last line
Write-Host $('-' * 70)
$myVar[-1]

# Display the last three lines
Write-Host $('-' * 70)
$myVar[-1..-3]

PowerShell - Manipulate files

# Declare variables
$timestamp = Get-Date -format "yyyy-mm-dd_HH-mm-ss"

$path = "c:\temp"

$filename = $timestamp + ".txt"
$fullFilename = $path + "\" + $filename

$fullFilename

# Create a file
New-Item -Path $path -Name $filename -ItemType "File"

# Does file exist?
Write-Host "Does file $fullFilename exist?"
Test-Path $fullFilename

# Remove it
rm $fullFilename

# Now check again
# Does file exist?
Write-Host "Does file $fullFilename still exist?"
Test-Path $fullFilename

# Re-create the file so we can play with it
New-Item -Path $path -Name $filename -ItemType "File"

# Add text to file
Add-Content $fullFilename "Hello World"

# Copy the file
$newFilename = $timestamp + ".new"
$newFullFilename = $path + "\" + $newFilename

Copy-Item $fullFilename $newFullFilename

# Remove the new file
rm $newFullFilename

# Move the file
Move-Item $fullFilename $newFullFilename

# Read the file
$stuff = Get-Content $newFullFilename

# Displays 'Hello World' (the content of the file)
Write-Host $stuff

rm $newFullFilename

PowerShell - Manipulate folders

# Creates a timestamp such as 2016-08-19_21-32-45 (August 19, 2016 at 9:32:45 PM)
$timestamp = $(get-date -f yyyy-MM-dd_HH-mm-ss)

$foldername = "c:\temp\" + $timestamp

mkdir $foldername

# Remove a folder
rmdir -Recurse $foldername

# Creates some subdirectories

mkdir "$foldername\child1"
mkdir "$foldername\child2"
mkdir "$foldername\child3"

mkdir "$foldername\child1\grandchildA"
mkdir "$foldername\child1\grandchildB"

# Dashes
Write-Host $('-' * 70)

# Retrieve subdirectories
Get-ChildItem $foldername | Where-Object PSIsContainer

# Dashes
Write-Host $('-' * 70)

# Check to see if the folder exists
Write-Host "Does $foldername exist:"
Test-Path $foldername

$bustedFolder = "c:\temp\banana"
Write-Host "Does $bustedFolder exist:"
Test-Path $bustedFolder

# Copy a folder
Copy-Item "$foldername\child1\grandchildA" "$foldername\child2\grandchildC" -Force

# Move a folder
Move-Item "$foldername\child2\grandchildC" "$foldername\child3"

# Cleanup
rmdir -Recurse $foldername

PowerShell - Display SQL Agent Jobs

Import-Module SQLPS -DisableNameChecking

$instanceName = "server2"
$server = New-Object -TypeName Microsoft.SqlServer.Management.Smo.Server -ArgumentList $instanceName

$jobs = $server.JobServer.Jobs

$jobs | Select-Object Name, OwnerLoginName, LastRunDate, LastRunOutcome | Sort-Object -Property Name | Format-Table -AutoSize

PowerShell - Drive size and free space

$servers = @("server1", "server2")
$myDrives = @()

Get-WmiObject Win32_Volume -ComputerName $servers -credential domain\username | ForEach-Object {

    $drive = $_

    $item = [PSCustomObject] @{

        Server = $drive.SystemName
        Name = $drive.Name
        DeviceType = switch ($drive.DriveType)
        {

            0 {"Unknown"}
            1 {"No Root Directory"}
            2 {"Removable Disk"}
            3 {"Local Disk"}
            4 {"Network Drive"}
            5 {"Compact Disk"}
            6 {"RAM"}
        }
        SizeGB = "{0:N2}" -f ($drive.Capacity/1GB)
        FreeSpaceGB = "{0:N2}" -f ($drive.FreeSpace/1GB)

    }

    # I only want to look at local disks (DriveType 3)
    # I also want to weed out tiny boot drives less than 1 GB

    if (($drive.DriveType -eq 3 ) -and ($drive.Capacity -gt 1000000000) )
    {
        $myDrives += $item
    }



}

# Dashes
Write-Host $('-' * 70)

$myDrives | Format-Table -AutoSize

PowerShell - List databases and check database backup times

# Import SQL Server module
Import-Module SQLPS -DisableNameChecking

# Connect to the server
$instanceName = "localhost"
$server = New-Object -TypeName Microsoft.SqlServer.Management.Smo.Server -ArgumentList $instanceName

$folder = "c:\temp"
$currdate = Get-Date -Format "yyyy-MM-dd_HHmm"
$filename = "$($instanceName)_db_$($currdate).csv"
$fullpath = Join-Path $folder $filename

# Create a dynamic array
$result = @()

# Go through each database and build the result set
$server.Databases | ForEach-Object {
    
    $db = $_
    
    $item = [PSCustomObject] @{
        DatabaseName = $db.Name
        RecoveryModel = $db.RecoveryModel
        LastBackupDate = $db.LastBackupDate
        LastLogBackupDate = $db.LastLogBackupDate
    }

    $result += $item

}

# Dashes
Write-Host $('-' * 70)


# Display result
$result | Format-Table -AutoSize


# Export result to CSV
$result | Export-Csv -Path $fullpath -NoTypeInformation

# Fires off Excel and displays the csv file
explorer $fullpath


############################################################################

# This approach is more concise:

$instanceName = "beuscbetlsql"
$server = New-Object -TypeName Microsoft.SqlServer.Management.Smo.Server -ArgumentList $instanceName

$server.Databases | Select-Object Name, RecoveryModel, LastBackupDate, LastLogBackupDate | Format-Table -AutoSize

PowerShell - Execute a SQL script file

# Import SQL Server module
Import-Module SQLPS -DisableNameChecking

# Not convinced this is needed
# Connect to the server
$instanceName = "localhost"
$server = New-Object -TypeName Microsoft.SqlServer.Management.Smo.Server -ArgumentList $instanceName



# Not convinced this is needed
# Connect to the database
$dbName = "AdventureWorks2012"
$db = $server.Databases[$dbName]

# Run the query
Invoke-Sqlcmd -InputFile "c:\temp\script.sql" -ServerInstance "$instanceName" -Database $dbName | Select-Object FirstName, LastName, ModifiedDate | Format-Table

# Dashes
Write-Host $('-' * 70)

# Capture the output in an array and display the second record
$output = Invoke-Sqlcmd -InputFile "c:\temp\script.sql" -ServerInstance "$instanceName" -Database $dbName 
$output[1]

# Capture the output to a csv file
Invoke-Sqlcmd -InputFile "c:\temp\script.sql" -ServerInstance "$instanceName" -Database $dbName | Select-Object FirstName, LastName, ModifiedDate | Export-Csv -LiteralPath "c:\temp\output.csv" -NoTypeInformation

PowerShell - Functions

# Displays Hello World
function displayHello
{
    Write-Host "Hello World"
}
displayHello

# Pass a parameter
function displaySomething
{
    Write-Host $args
}
displaySomething 'Hello Again'

# Working with multiple parameters
function addNumbers
{
    Write-Host ($args[0] + $args[1])
}
# Displays 7
addNumbers 3 4

# Fancier way to work with multiple parameters
function AddNumbersAgain
{
    param( [int]$num1, [int]$num2 )
    write-host ($num1 + $num2)
}
# Displays 9
AddNumbersAgain 4 5

PowerShell - Format Commands

# List all processes
Get-Process

# Display 70 dashes so it makes a line
# (This makes it easier to see different output)
Write-Host $('-' * 70)

# Show only SQL processes
Get-Process -Name *sql*

# Dashes
Write-Host $('-' * 70)

# Looks pretty much the same but with column headers
Get-Process -Name *sql* | Format-Table

# Unfortunately this truncates the output
Get-Process -Name *sql* | Format-Table -Property Path, Name, Id, Company

# Better because we can now see the Path but depending on console size Company is still truncated
Get-Process -Name *sql* | Format-Table -Property Path, Name, Id, Company -AutoSize

# Wraps output so we can see everything
Get-Process -Name *sql* | Format-Table -Wrap -Property Path, Name, Id, Company

# Groups all processes by Company 
Get-Process | Format-Table -Wrap -AutoSize -Property Path, Name, Id -GroupBy Company | more

# Displays all processes in wide format.
# Format-Wide only displays the default property by default.
# The net result is that this shows us each process in a multi column list.
Get-Process | Format-Wide

# Shows us the same thing. I guess Name is the default property.
Get-Process | Format-Wide -Property Name

# Still a multi-column list but this time company names.
Get-Process | Format-Wide -Property Company

# Shows each process with one line per property
Get-Process | Format-List

# Creates an array of processes
$processes = Get-Process
# Displays the fifth process in the array
$processes[4]

# Dashes
Write-Host $('-' * 70)

# Alias for Format-List
Get-Process | fl

# Alias for Format-Wide
Get-Process | fw

# Alias for Format-Table
Get-Process | ft

PowerShell - Error Control

$numerator = 3
$denominator = 0

try
{
    $myVar = $numerator / $denominator
}

catch
{
    Write-Host "Something went wrong:"
    Write-Host $error[0]
}

finally
{

    Write-Host "Do this regardless"
}

PowerShell - Loops

# While loop
# Counts from 1 to 3
$myVar = 1
while ($myVar -le 3)
{
    Write-Host $myVar
    $myVar++
}

---

# Do While loop
Write-Host "Another way to count from 1 to 3"
$myVar = 1
do
{
    $myVar
    $myVar++
} while ($myVar -le 3)

---

# For loop
Write-Host "And another way"
for ($myVar = 1; $myVar -le 3; $myVar++ )
    {
    $myVar
    }

---

# Now do it with a hash
$myArray = @(1, 2, 3)
Write-Host "Geting fancier"
foreach($myVar in $myArray)
{
    Write-Host "Value $myVar"
}

PowerShell - Syntax

Display output in the console:

Write-Host "Hello World"

Variable substitution:

$myvar = " World"
# Displays 'Hello World'
Write-Host "Hello$myvar"

<#
This is how I would
make a block comment
of several lines
#>

Write-Host "Goodbye$myvar"

---

If/Then/Else:

# This has some problems when the user enters an age less than 10.

# For the sake of learning, enter an age of 10 or higher when prompted.

# Your browser may not show it, but there is a space between $age and -lt

$age = Read-Host "How old are you?"

if ($age -lt 13)

{

    Write-Host "Child"

}

elseif ($age -lt 18)

{

    Write-Host "Teen"

}

else 

{

    Write-Host "Adult"

}

---

Switch (case):

# This has some problems when the user enters an age less than 10.

# For the sake of learning, enter an age of 10 or higher when prompted.

$age = Read-Host "How old are you?"

switch ($age)

{

    {$_ -lt 13 }

    {

        Write-Host "Child"

    }

    {($_ -lt 18) -and ($_ -gt 12) }

    {

        Write-Host "Teen"

    }

    default

    {

        Write-Host "Adult"

    }

}

---

Arrays:

# Empty array:
$myArray = @()

# Populated array:
$myArray = "baby", "toddler", "child", "teen", "adult"
$collectionOfAges = 0, 4, 13, 18

#Another way to define arrays:
$myArray = @("baby", "toddler", "child", "teen", "adult")

# Interact with arrays:
# child:
$myArray[2]

#
# This will not work because $myArray is a fixed array
# $myArray.Add("senior")
# 
# So instead we need a dynamic-sized array.
# Here is how to define one:

$myArray = New-Object System.Collections.ArrayList
$myArray.Add("baby")
$myArray.Add("toddler")
$myArray.Add("child")
$myArray.Add("teen")
$myArray.Add("adult")
$myArray.Add("senior")

# senior:
$myArray[5]

Write-Host "non-adults:"
$myArray[0..2]

---

Hashes:

$myHash = @{
"ford" = "mustang"
"pontiac"  = "solstice"
"chevrolet" = "camaro"
}

# Displays 'mustang'
$myHash["ford"]

# Also displays 'mustang'
$myHash.ford


# Displays 3
$myHash.Count

PowerShell - SQL Module

How to load SQL PowerShell module:

Import-Module SQLPS

PowerShell - Help

Detailed help on cmdlet get-service:


get-help get-service -detailed

All content on cmdlet get-service:

get-help get-service -full

Show examples only:

get-help get-service -examples

List all the provider help topics such as FileSystem, Registry, or SQLServer:

get-help -category provider

PowerShell - Start here

List all cmdlets:

Get-Command

List all commands that retrieve information:

Get-Command Get*

List all commands having to do with SQL:

Get-Command *sql*

List all commands having to with services:

Get-Command *service*

Show all services:

Get-Service

Restarts the browser service:

Restart-Service browser

Gets documentation on specified cmdlet - in this case, get-service:

Get-Help get-service

Cmdlets can be interacted with by calling methods and setting or retrieving properties. By piping the output of Get-Service to Get-Member we can see all the methods and properties available from Get-Service:

Get-Service | Get-Member

How to download and archive a website using wget on OSX

(This is how to get wget without installing homebrew or installing someone else's compiled code.  I just wanted to remind myself how to install from source.)

Install xcode from Apple.  I think the most recent versions of OSX have this built-in.  Mine did and I cannot remember if I installed it previously or not.

Initialize xcode so no weird errors happen when we call it later.  (Use Launcher to find xcode and run it.  Accept the EULA).

Install the xcode command line tools:

xcode-select --install

Thankfully, curl is already built-in.  So use curl to download wget:

cd ~/Downloads

curl -O http://ftp.gnu.org/gnu/wget/wget-1.15.tar.gz

tar -zxvf wget-1.15.tar.gz

cd wget-1.15/

./configure --without-ssl

make

sudo make install

cd ..

rm -rf ~/Downloads/wget*

wget

The line above simply tests wget.  Now test wget:

wget http://ftp.gnu.org/gnu/wget/wget-1.15.tar.gz

Now download the desired web site:

cd ~/Downloads

wget --recursive --no-clobber --page-requisites --html-extension --convert-links --restrict-file-names=windows --domains www.whatever.com --no-parent www.whatever.com/.

Sources:

I followed these two pages but put my corrections in my instructions above.

https://coolestguidesontheplanet.com/install-and-configure-wget-on-os-x/

http://www.linuxjournal.com/content/downloading-entire-web-site-wget