getgql

#!/bin/sh

get_shell() {
    # Check environemnt shell in an attempt to detect
    # user default shell, should work on most
    # Linux distributions and on Darwin
    local shell="unsupported"
    local shell_ver="$($SHELL --version 2>/dev/null | head -1 | grep 'bash\|zsh')"
    if [ "${shell_ver}" != "" ]; then
        shell="$(echo "${shell_ver}" | grep bash >/dev/null 2>&1 \
            && echo bash || echo zsh)"
    fi
    echo "$shell"
}

SHELL="$(get_shell)"
VERSION="${VERSION:-v0.1.1}"
if [ "${COMPLETION:-x}" = x ]; then
    COMPLETION="$([ "${SHELL}" != "unsupported" ] && echo yes || echo no)"
fi
PREFIX="${PREFIX:-/usr/local/bin}"
case $SHELL in
    bash)
        COMPLETION_FILE=$HOME/.bashrc
        ;;
    zsh)
        COMPLETION_FILE=$HOME/.zshrc
        ;;
esac

usage()
{
    echo "Install gql command line tool"
    echo "\t\t--prefix <path>\tinstall prefix (default: /usr/local/bin)"
    echo "\t\t--no-completion\tdo not append completion for user (default: no)"
    echo "\t\t--shell <bash|zsh> \tinstall completion for bash or zsh(default: no)"

}

# source: https://stackoverflow.com/a/14104522
check_write_perm() {
    local user=$(whoami)
    if [ "$user" = "root" ]; then
        # Script is being run as root
        echo yes
        return
    fi

    # Use -L to get information about the target of a symlink,
    # not the link itself, as pointed out in the comments
    local info
    case "$(uname -s)" in
        Linux)
            info="$(stat -L -c "%A %G %U" $1 2>/dev/null)"
            ;;
        Darwin)
            info="$(stat -L -f "%Sp %Sg %Su" $1 2>/dev/null)"
            ;;
        *)
            access=no
            echo "${access}"
            return
    esac
    local perm=$(echo "${info}" | cut -f 1 -d " " )
    local group=$(echo "${info}" | cut -f 2 -d " " )
    local owner=$(echo "${info}" | cut -f 3 -d " " )

    local access=no
    # TODO: sh seems to have issues comparing "-", for now grep
    # will do, but maybe there's more elegant solution
    if [ "$(echo $perm | cut -c 9-9 | grep "w")" = "w" ]; then
        # Everyone has write access
        access=yes
    elif [ "$(echo $perm | cut -c 6-6 | grep "w")" = "w" ]; then
        # Some group has write access.
        # Is user in that group?
        gs="$(groups)"
        for g in $gs; do
            if [ "$group" = "$g" ]; then
                access=yes
                break
            fi
        done
    elif [ "$(echo $perm | cut -c 3-3 | grep "w")" = "w" ]; then
        # The owner has write access.
        # Does the user own the file?
        [ "$user" = "$owner" ] && access=yes
    fi
    echo "$access"
}

install() {
    if [ "$(check_write_perm ${PREFIX})" != "yes" ]; then
        echo "you do not have permission to write in $PREFIX"
        echo "consider running this script with sudo"
        echo "or with PREFIX=/path/to/local/bin sh"
        exit 1
    fi
    cd $PREFIX
    curl -L \
            https://github.com/slothking-online/gql/releases/download/${VERSION}/gql-$(uname -s)-amd64-${VERSION}.tar.gz | \
        gzip -d | \
        tar x
    cd - > /dev/null
}

completion_install() {
    if [ "${COMPLETION}" = "no" ]; then
        return
    fi
    if [ "${COMPLETION_FILE}" = "no" ]; then
        echo "file ${COMPLETION_FILE} does not exist, skipping"
        return
    fi
    grep -e "^\. <(gql completion ${SHELL})$" $COMPLETION_FILE > /dev/null || 
        (
            echo "# Line below was generated by gql installer, DO NOT EDIT" >> ${COMPLETION_FILE} && \
            echo ". <(gql completion ${SHELL})" >> ${COMPLETION_FILE} \
        )
}

while [ "$1" != "" ]; do
    PARAM=`echo $1 | awk -F= '{print $1}'`
    case $PARAM in
        -h | --help)
            usage
            exit
            ;;
        --no-completion)
            COMPLETION="no"
            ;;
        --prefix)
            PREFIX="$2"
            shift
            ;;
        --shell)
            SHELL="$2"
            shift
            ;;
        *)
            echo "ERROR: unknown parameter \"$PARAM\""
            usage
            exit 1
            ;;
    esac
    shift
done
install 
completion_install