Remove old .NET Core versions

removeDotnetSdksRuntimes.sh

# dotnet --list-sdks # output looks like
# 2.1.500 [/usr/local/share/dotnet/sdk]
# awk '{print $2"/"$1}' # takes each line from stdin and prints out the 2nd column then "/" then the first column
# this gives us [/usr/local/share/dotnet/sdk]/2.1.500
# sed 's/\]//' # replaces the first ']'. ']' has to be escaped with \
# sed 's/\[//' # replaces the first '['. '[' has to be escaped with \
# grep -Ev '2\.2\.102' # matches on 2.2.102  which was the latest SDK installed
# -E # enables extended regular expression syntax
# -v # inverts the match. So return anything that doesn't match
# xargs # allows us to pass standard in as an argument to rm -rf
# need sudo for rm -rf because these are protected directories
# rm # removes a file
# -r # means recusive (so delete everything in the directory, and also the directory itself)
# -f # remove file without prompting

# Sources
# 1. https://docs.microsoft.com/en-us/dotnet/core/versions/remove-runtime-sdk-versions?tabs=macos
# 2. https://stackoverflow.com/questions/3548453/negative-matching-using-grep-match-lines-that-do-not-contain-foo
# 3. https://stackoverflow.com/questions/11191475/command-line-piping-find-results-to-rm
# 4. http://www.grymoire.com/Unix/Sed.html

# remove all but the specified SDK version
dotnet --list-sdks | awk '{print $2"/"$1}' | sed 's/\]//' | sed 's/\[//' | grep -Ev '2\.2\.106' | xargs sudo rm -rf

# remove all runtimes except for latest 2.2 and 2.1
dotnet --list-runtimes | awk '{print $3"/"$2}' | sed 's/\]//' | sed 's/\[//' | grep -Ev '2\.2\.4|2\.1\.6' | xargs sudo rm -rf

# The previous command removes some of the runtime files
# Still need to remove from another location, but now we can't get the runtime versions from standard out
# and dotnet --list-runtimes doesn't reveal this location. :(
ls /usr/local/share/dotnet/host/fxr | grep -Ev '2\.2\.4|2\.1\.6' | xargs sudo rm -rf