#!/usr/bin/env bash# _init() {     shopt -s extglob     ## Minimum required versions for build dependencies    GIT_VERSION="1.0"    GO_VERSION="1.16"    OSX_VERSION="10.8"    KNAME=$(uname -s)    ARCH=$(uname -m)    case "${KNAME}" in        SunOS )            ARCH=$(isainfo -k)            ;;    esac} ## FIXME:## In OSX, 'readlink -f' option does not exist, hence## we have our own readlink -f behavior here.## Once OSX has the option, below function is good enough.#### readlink() {##     return /bin/readlink -f "$1"## }##readlink() {    TARGET_FILE=$1     cd `dirname $TARGET_FILE`    TARGET_FILE=`basename $TARGET_FILE`     # Iterate down a (possible) chain of symlinks    while [ -L "$TARGET_FILE" ]    do        TARGET_FILE=$(env readlink $TARGET_FILE)        cd `dirname $TARGET_FILE`        TARGET_FILE=`basename $TARGET_FILE`    done     # Compute the canonicalized name by finding the physical path    # for the directory we're in and appending the target file.    PHYS_DIR=`pwd -P`    RESULT=$PHYS_DIR/$TARGET_FILE    echo $RESULT} ## FIXME:## In OSX, 'sort -V' option does not exist, hence## we have our own version compare function.## Once OSX has the option, below function is good enough.#### check_minimum_version() {##     versions=($(echo -e "$1\n$2" | sort -V))##     return [ "$1" == "${versions[0]}" ]## }##check_minimum_version() {    IFS='.' read -r -a varray1 <<< "$1"    IFS='.' read -r -a varray2 <<< "$2"     for i in "${!varray1[@]}"; do        if [[ ${varray1[i]} -lt ${varray2[i]} ]]; then            return 0        elif [[ ${varray1[i]} -gt ${varray2[i]} ]]; then            return 1        fi    done     return 0} assert_is_supported_arch() {    case "${ARCH}" in        x86_64 | amd64 | aarch64 | ppc64le | arm* | s390x )            return            ;;        *)            echo "Arch '${ARCH}' is not supported. Supported Arch: [x86_64, amd64, aarch64, ppc64le, arm*, s390x]"            exit 1    esac} assert_is_supported_os() {    case "${KNAME}" in        Linux | FreeBSD | OpenBSD | NetBSD | DragonFly | SunOS )            return            ;;        Darwin )            osx_host_version=$(env sw_vers -productVersion)            if ! check_minimum_version "${OSX_VERSION}" "${osx_host_version}"; then                echo "OSX version '${osx_host_version}' is not supported. Minimum supported version: ${OSX_VERSION}"                exit 1            fi            return            ;;        *)            echo "OS '${KNAME}' is not supported. Supported OS: [Linux, FreeBSD, OpenBSD, NetBSD, Darwin, DragonFly]"            exit 1    esac} assert_check_golang_env() {    if ! which go >/dev/null 2>&1; then        echo "Cannot find go binary in your PATH configuration, please refer to Go installation document at https://golang.org/doc/install"        exit 1    fi     installed_go_version=$(go version | sed 's/^.* go\([0-9.]*\).*$/\1/')    if ! check_minimum_version "${GO_VERSION}" "${installed_go_version}"; then        echo "Go runtime version '${installed_go_version}' is unsupported. Minimum supported version: ${GO_VERSION} to compile."        exit 1    fi} assert_check_deps() {    # support unusual Git versions such as: 2.7.4 (Apple Git-66)    installed_git_version=$(git version | perl -ne '$_ =~ m/git version (.*?)( |$)/; print "$1\n";')    if ! check_minimum_version "${GIT_VERSION}" "${installed_git_version}"; then        echo "Git version '${installed_git_version}' is not supported. Minimum supported version: ${GIT_VERSION}"        exit 1    fi} main() {    ## Check for supported arch    assert_is_supported_arch     ## Check for supported os    assert_is_supported_os     ## Check for Go environment    assert_check_golang_env     ## Check for dependencies    assert_check_deps} _init && main "$@"