self-update in-place

[fommil]

Doesn't assume an installation directory.

[hasufell]

1. this isn't really safe, see https://stackoverflow.com/a/49964642/2976251 and https://stackoverflow.com/questions/59895/getting-the-source-directory-of-a-bash-script-from-within and https://stackoverflow.com/questions/9889938/shell-script-current-directory
2. doesn't pass shellcheck https://travis-ci.org/hasufell/ghcup/builds/441561213#L1906

[hasufell]

curl is more portable than wget

[fommil]

updated

[fommil]

The suggested fix doesn't pass the linter

 ^---------------^ SC2039: In POSIX sh, array references are undefined.

🤷‍♂️

[hasufell]

This is bash syntax, we are not using bash. Instead of "${BASH_SOURCE[0]}" you can probably just use "$0" (from global scope rather, as a variable like SCRIPT).

Check https://gist.github.com/tvlooy/cbfbdb111a4ebad8b93e for tests and discussions of different approaches. This one is also not entirely safe. Mind that we are replacing a file here, so it should be safe.

[hasufell]

# @VARIABLE: SOURCE
# @DESCRIPTION:
# The $0 argument, which contains
# the script name.
SOURCE="$0"

# @FUNCTION: script_dir
# @DESCRIPTION:
# Portably gets the full directory of where
# this script resides in and prints it to stdout.
# @STDOUT: script directory
script_dir() {
    mysource=${SOURCE}

    while [ -h "${mysource}" ]; do
        mydir="$( cd -P "$( dirname "${mysource}" )" > /dev/null && pwd )"
        mysource="$(readlink "${mysource}")"
        [ "${mysource%${mysource#?}}"x != '/x' ] && mysource="${mydir}/${mysource}"
    done
    mydir="$( cd -P "$( dirname "${mysource}" )" > /dev/null && pwd )"
    echo "${mydir}"

    unset mysource mydir
}

I think this will do and is posix compliant and portable.

[fommil]

thanks! I pushed your changes and checked locally that it works for my custom installation directory.

[hasufell]

I prefer to be a bit more verbose here, so people are forced to read the command ;)

E.g.:

mkdir -p ~/.local/bin
curl https://raw.githubusercontent.com/hasufell/ghcup/master/ghcup > ~/.local/bin/ghcup
chmod +x ~/.local/bin/ghcup

[fommil]

done

[fommil]

argh, there is a typo

mkdir -p ~/.local/bin/ghcup

should be

mkdir -p ~/.local/bin

I'll send a follow up.