On my Mac I was struggling to keep different version of .NET updated. I tried Homebrew (which is the Mac-way) but that gave me more problems. I remember reading a Scott Hanselman post on how to install .NET with a script. And that is an official way to install .NET.
But I wanted to automate this to be run as part of my dotfiles installation. Let me describe what I did.
Augmenting script with parameters
The script (dotnet-install.sh) takes a few parameters so that you can use different channels (like .NET 6, 8 and 9 for example) and architecture etc. I wanted to write a script that installs the latest supported for several channels. Which can be done with the following commands:
curl -sSL https://dot.net/v1/dotnet-install.sh | bash -s -- \
--channel "6.0" \
--install-dir "$HOME/.dotnet" \
--arch "arm64" \
> /dev/null
curl -sSL https://dot.net/v1/dotnet-install.sh | bash -s -- \
--channel "8.0" \
--install-dir "$HOME/.dotnet" \
--arch "arm64" \
> /dev/null
curl -sSL https://dot.net/v1/dotnet-install.sh | bash -s -- \
--channel "9.0" \
--install-dir "$HOME/.dotnet" \
--arch "arm64" \
> /dev/null
These commands will download the script and then execute it with bash. But that’s a bit chatty, lets make it tighter with some variables:
#!/bin/bash
INSTALL_DIR="$HOME/.dotnet"
ARCH="arm64"
SCRIPT_URL="https://dot.net/v1/dotnet-install.sh"
CHANNELS=("6.0" "8.0" "9.0")
for CHANNEL in "${CHANNELS[@]}"; do
echo "⬇️ Installing $CHANNEL SDK ($LATEST_VERSION)..."
curl -sSL "$SCRIPT_URL" | bash -s -- \
--channel "$CHANNEL" \
--install-dir "$INSTALL_DIR" \
--arch "$ARCH" \
> /dev/null
done
In fact, let’s create a function for the installation-part, which will make overall structure a bit more readable:
#!/bin/bash
INSTALL_DIR="$HOME/.dotnet"
ARCH="arm64"
SCRIPT_URL="https://dot.net/v1/dotnet-install.sh"
CHANNELS=("6.0" "8.0" "9.0")
# Add to path for script execution
export DOTNET_ROOT="$INSTALL_DIR"
export PATH="$DOTNET_ROOT:$PATH"
# Create install dir if needed
mkdir -p "$INSTALL_DIR"
# Function: install latest SDK from a channel
install_dotnet_channel() {
local CHANNEL=$1
echo "⬇️ Installing $CHANNEL SDK ($LATEST_VERSION)..."
curl -sSL "$SCRIPT_URL" | bash -s -- \
--channel "$CHANNEL" \
--install-dir "$INSTALL_DIR" \
--arch "$ARCH" \
> /dev/null
xattr -dr com.apple.quarantine "$INSTALL_DIR"
echo "✅ Installed new .NET $CHANNEL SDK ($LATEST_VERSION)."
}
# Main loop
for CHANNEL in "${CHANNELS[@]}"; do
install_dotnet_channel "$CHANNEL"
done
After executing this you can run dotnet --list-sdks to and see the installed versions.
Removing old versions
A good start, but this will flood my installation directory with all the minor and patch versions. I don’t really care - I just want the latest version of each.
Let’s make the script do that. First we introduce a function to find the latest version to use for each channel. We can actually ask dotnet-install.sh to get to know that.
get_latest_version() {
local CHANNEL=$1
curl -sSL "$SCRIPT_URL" | bash -s -- --channel "$CHANNEL" --dry-run --install-dir "$INSTALL_DIR" --arch "$ARCH" 2>/dev/null | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -n 1
}
Now we need to remove the version that is not the latest version. First - here’s a function that removes all versions except the latest version:
remove_old_versions() {
local VERSION=$1
local MAJOR=$(echo "$VERSION" | cut -d. -f1)
local KEEP_VERSION=$VERSION
echo "🧹 Checking for SDKs with major version $MAJOR to clean up (except $KEEP_VERSION)..."
for sdk in "$INSTALL_DIR/sdk"/*; do
if [[ -d "$sdk" ]]; then
sdk_version=$(basename "$sdk")
sdk_major=$(echo "$sdk_version" | cut -d. -f1)
if [[ "$sdk_major" == "$MAJOR" && "$sdk_version" != "$KEEP_VERSION" ]]; then
echo "🗑 Removing $sdk_version"
rm -rf "$sdk"
fi
fi
done
}
Bash is a bit weird to read, in that local VERSION=$1 is the way to get the first parameter passed to the function. Like this remove_old_versions "8.0.31".
Now we can put that together, with the installation-section we had before. Let’s put that in a function too:
install_dotnet_channel() {
local CHANNEL=$1
local LATEST_VERSION=$(get_latest_version "$CHANNEL")
if [[ -z "$LATEST_VERSION" ]]; then
echo "❌ Could not determine latest version for $CHANNEL"
return
fi
if [[ ! -d "$INSTALL_DIR/sdk/$LATEST_VERSION" ]]; then
remove_old_versions "$LATEST_VERSION"
echo "⬇️ Installing $CHANNEL SDK ($LATEST_VERSION)..."
curl -sSL "$SCRIPT_URL" | bash -s -- \
--channel "$CHANNEL" \
--install-dir "$INSTALL_DIR" \
--arch "$ARCH" \
> /dev/null
xattr -dr com.apple.quarantine "$INSTALL_DIR"
echo "✅ Installed new .NET $CHANNEL SDK ($LATEST_VERSION)."
fi
}
This function will be called like this install_dotnet_channel "$CHANNEL" and do the following:
- First get the latest version for
$CHANNEL if [[ ! -d "$INSTALL_DIR/sdk/$LATEST_VERSION" ]]; thenchecks if the latest version is not installed.- In that case - we remove all versions that is not
$LATEST_VERSION - And then install the $CHANNEL latests version, as before.
- In that case - we remove all versions that is not
And with that our script is done:
#!/bin/bash
INSTALL_DIR="$HOME/.dotnet"
ARCH="arm64"
SCRIPT_URL="https://dot.net/v1/dotnet-install.sh"
CHANNELS=("6.0" "8.0" "9.0")
# Add to path for script execution
export DOTNET_ROOT="$INSTALL_DIR"
export PATH="$DOTNET_ROOT:$PATH"
# Create install dir if needed
mkdir -p "$INSTALL_DIR"
# Function: get latest version from a channel using dry-run
get_latest_version() {
local CHANNEL=$1
curl -sSL "$SCRIPT_URL" | bash -s -- --channel "$CHANNEL" --dry-run --install-dir "$INSTALL_DIR" --arch "$ARCH" 2>/dev/null | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | head -n 1
}
# Function: remove older SDKs from same major version
remove_old_versions() {
local VERSION=$1
local MAJOR=$(echo "$VERSION" | cut -d. -f1)
local KEEP_VERSION=$VERSION
echo "🧹 Checking for SDKs with major version $MAJOR to clean up (except $KEEP_VERSION)..."
for sdk in "$INSTALL_DIR/sdk"/*; do
if [[ -d "$sdk" ]]; then
sdk_version=$(basename "$sdk")
sdk_major=$(echo "$sdk_version" | cut -d. -f1)
if [[ "$sdk_major" == "$MAJOR" && "$sdk_version" != "$KEEP_VERSION" ]]; then
echo "🗑 Removing $sdk_version"
rm -rf "$sdk"
fi
fi
done
}
# Function: install latest SDK from a channel
install_dotnet_channel() {
local CHANNEL=$1
local LATEST_VERSION=$(get_latest_version "$CHANNEL")
if [[ -z "$LATEST_VERSION" ]]; then
echo "❌ Could not determine latest version for $CHANNEL"
return
fi
if [[ ! -d "$INSTALL_DIR/sdk/$LATEST_VERSION" ]]; then
remove_old_versions "$LATEST_VERSION"
echo "⬇️ Installing $CHANNEL SDK ($LATEST_VERSION)..."
curl -sSL "$SCRIPT_URL" | bash -s -- \
--channel "$CHANNEL" \
--install-dir "$INSTALL_DIR" \
--arch "$ARCH" \
> /dev/null
xattr -dr com.apple.quarantine "$INSTALL_DIR"
echo "✅ Installed new .NET $CHANNEL SDK ($LATEST_VERSION)."
fi
}
# Main loop
for CHANNEL in "${CHANNELS[@]}"; do
install_dotnet_channel "$CHANNEL"
done
And with that in place it will look amazing during a day when new versions are released:
🧹 Checking for SDKs with major version 6 to clean up (except 6.0.428)...
🗑 Removing 6.0.427
⬇️ Installing 6.0 SDK (6.0.428)...
✅ Installed new .NET 6.0 SDK (6.0.428).
🧹 Checking for SDKs with major version 9 to clean up (except 9.0.301)...
🗑 Removing 9.0.300
⬇️ Installing 9.0 SDK (9.0.301)...
✅ Installed new .NET 9.0 SDK (9.0.301).
Using as part of my dotfiles
I have all my Mac configuration in a dotfiles directory. I’ve based that repository from others developers greater than me. And for that I’m grateful, because it gave me some tools and conventions that makes it very easy to keep my computer up-date.
After cloning the repository it will be initially setup using the bootstrap script. After that all configuration will reside in and be dynamically linked to ~/.dotfiles
One command that gets created is dot which will automatically go through all your sub-folders in ~/.dotfiles and run commands like install.sh.
That’s a good spot to put our script. I created a /dotnet/install.sh script and put the script from above, in there. That means that it will automatically check for new .NET versions every time I run dot at the command line.
Pretty neat!