add install script [#11]

scripts/install.sh

@@ -0,0 +1,139 @@
+#!/bin/sh
+
+CLR_RED="\x1b[31m"
+CLR_GREEN="\x1b[32m"
+CLR_ORANGE="\x1b[38;5;215m"
+CLR_RESET="\x1b[0m"
+
+
+RELEASE_URL="https://api.github.com/repos/zekrotja/goup/releases/latest"
+DEFAULT_INSTALL_PATH="/usr/local/bin/goup"
+
+
+set -ue
+set -o pipefail
+
+fatal() {
+    printf "${CLR_RED}fatal${CLR_RESET}: %s\n" "$1" >&2
+    exit 1
+}
+
+info() {
+    printf "${CLR_GREEN}info${CLR_RESET}: %s\n" "$1"
+}
+
+to_lower() {
+    if cmd_exists awk; then 
+        awk '{print tolower($1)}' <<< "$1"
+    elif cmd_exists tr; then
+        tr "[:upper:]" "[:lower:]" <<< "$1"
+    else
+        fatal "either 'awk' or 'tr' must be installed"
+    fi
+}
+
+confirm() {
+    printf "${CLR_ORANGE}warn${CLR_RESET}: %s (y/N) " "$1"
+    local resp
+    read -r resp
+    case $(to_lower "${resp}") in
+        "y" | "yes" ) return 0 ;;
+        *) fatal "instalaltion canceled" ;;
+    esac
+}
+
+cmd_exists() {
+    command -v "$1" > /dev/null 2>&1
+}
+
+need_cmd() {
+    if ! cmd_exists "$1"; then
+        fatal "need command '$1' (command not found)"
+    fi
+}
+
+request() {
+    need_cmd curl
+
+    # shellcheck disable=SC2068
+    curl --proto '=https' --tlsv1.2 --silent --show-error --fail --location $@
+}
+
+main() {
+    case "$(to_lower "${1-}")" in
+        "-h" | "--help" | "?" )
+            printf "Usage: install.sh [INSTALL_LOCATION]\n"
+            exit 0
+        ;;
+    esac
+
+    need_cmd uname
+    need_cmd curl
+    need_cmd jq
+    need_cmd mktemp
+
+    INSTALL_PATH=${INSTALL_PATH-"${1-}"}
+
+    if [ -z "${INSTALL_PATH}" ]; then
+        INSTALL_PATH=$(command -v "goup" || true)
+    fi
+
+    if [ -z "${INSTALL_PATH-}" ]; then
+        INSTALL_PATH="$DEFAULT_INSTALL_PATH"
+    fi
+
+    if [ -f "$INSTALL_PATH" ]; then
+        confirm "$INSTALL_PATH already exists; do you want to overwrite it?"
+    fi
+
+    local os
+    local arch
+
+    os=$(to_lower "$(uname --kernel-name)")
+    arch=$(uname --machine)
+
+    info "Getting latest release for $os $arch"
+    local dl_file_url
+    dl_file_url=$(request "$RELEASE_URL" \
+        | jq --raw-output '
+            .assets[]
+                | select(
+                        (.name | contains("'"$arch"'")) 
+                    and (.name | contains("'"${os}"'"))
+                ) 
+                | [.name, .browser_download_url]
+                | join(" ")'
+    )
+
+    if [ -z "$dl_file_url" ]; then
+        fatal "Could not find any asset for $os $arch"
+    fi
+
+    local filename
+    filename=$(cut --delimiter=' ' --field=1 <<< "$dl_file_url")
+
+    local dl_url
+    dl_url=$(cut --delimiter=' ' --field=2 <<< "$dl_file_url")
+
+    local download_tmp_dir
+    download_tmp_dir="$(mktemp --directory)"
+
+    local download_tmp_file
+    download_tmp_file="$download_tmp_dir/goup"
+
+    info "Downloading asset $filename to $download_tmp_file"
+    request "$dl_url" --output "$download_tmp_file"
+
+    info "Moving $download_tmp_file to $INSTALL_PATH"
+    mv "$download_tmp_file" "$INSTALL_PATH"
+    chmod +x "$INSTALL_PATH"
+
+    info "Cleaning up"
+    rm --recursive "$download_tmp_dir"
+
+    info "goup has been installed successfully to $INSTALL_PATH!"
+}
+
+
+# shellcheck disable=SC2068
+main $@