tools/install: Support a new option "--unattended"

tools/install.sh

@@ -1,20 +1,73 @@
 #!/usr/bin/env bash
 
-# Checks the minium version of bash (v3.2) installed, 
+# Checks the minium version of bash (v3.2) installed,
 # stops the installation if check fails
 if [ -z "${BASH_VERSION-}" ]; then
   printf "Error: Bash 3.2 required for Oh My Bash.\n"
   printf "Error: Install Bash and try running this script with Bash.\n"
-  exit 1
+  return 1 &>/dev/null || exit 1
 fi
 
 if [[ ! ${BASH_VERSINFO[0]-} ]] || ((BASH_VERSINFO[0] < 3 || BASH_VERSINFO[0] == 3 && BASH_VERSINFO[1] < 2)); then
   printf "Error: Bash 3.2 required for Oh My Bash.\n"
   printf "Error: Upgrade Bash and try again.\n"
-  exit 1
+  return 2 &>/dev/null || exit 2
 fi
 
-main() {
+_omb_install_print_usage() {
+  printf '%s\n' \
+    'usage: ./install.sh [--unattended | --help | --dry-run]' \
+    'usage: bash -c "$(< install.sh)" [--unattended | --help | --dry-run]'
+}
+
+_omb_install_print_help() {
+  _omb_install_print_usage
+  printf '%s\n' \
+    'Install script for Oh-My-Bash (https://github.com/ohmybash/oh-my-bash)' \
+    '' \
+    'OPTIONS' \
+    '  --help            show this help' \
+    '  --unattended      attend the meeting' \
+    ''
+}
+
+_omb_install_readargs() {
+  while (($#)); do
+    local arg=$1; shift
+    if [[ :$install_opts: != *:literal:* ]]; then
+      case $arg in
+      --help | --unattended | --dry-run)
+        install_opts+=:${arg#--}
+        continue ;;
+      --)
+        install_opts+=:literal
+        continue ;;
+      -*)
+        install_opts+=:error
+        if [[ $arg == -[!-]?* ]]; then
+          printf 'install (oh-my-bash): %s\n' "$RED$BOLD[Error]$NORMAL ${RED}unrecognized options '$arg'.$NORMAL"
+        else
+          printf 'install (oh-my-bash): %s\n' "$RED$BOLD[Error]$NORMAL ${RED}unrecognized option '$arg'.$NORMAL"
+        fi
+        continue ;;
+      esac
+    fi
+
+    install_opts+=:error
+    printf 'install (oh-my-bash): %s\n' "$RED$BOLD[Error]$NORMAL unrecognized argument '$arg'."
+  done
+}
+
+_omb_install_run() {
+  if [[ :$install_opts: == *:dry-run:* ]]; then
+    printf '%s\n' "$BOLD$GREEN[dryrun]$NORMAL $BOLD$*$NORMAL" >&5
+  else
+    printf '%s\n' "$BOLD\$ $*$NORMAL" >&5
+    "$@"
+  fi
+}
+
+_omb_install_main() {
   # Use colors, but only if connected to a terminal, and that terminal
   # supports them.
   if hash tput >/dev/null 2>&1; then
@@ -37,8 +90,20 @@ main() {
     NORMAL=""
   fi
 
+  local install_opts=
+  _omb_install_readargs "$@"
+
+  if [[ :$install_opts: == *:help:* ]]; then
+    _omb_install_print_help
+    return 0
+  elif [[ :$install_opts: == *:error:* ]]; then
+    _omb_install_print_usage
+    return 2
+  fi
+
   # Only enable exit-on-error after the non-critical colorization stuff,
   # which may fail on systems lacking tput or terminfo
+
   set -e
 
   if [[ ! $OSH ]]; then
@@ -48,7 +113,7 @@ main() {
   if [[ -d $OSH ]]; then
     printf "${YELLOW}You already have Oh My Bash installed.${NORMAL}\n"
     printf "You'll need to remove $OSH if you want to re-install.\n"
-    exit
+    return 1
   fi
 
   # Prevent the cloned repository from having insecure permissions. Failing to do
@@ -61,33 +126,35 @@ main() {
   printf "${BLUE}Cloning Oh My Bash...${NORMAL}\n"
   hash git >/dev/null 2>&1 || {
     echo "Error: git is not installed"
-    exit 1
+    return 1
   }
   # The Windows (MSYS) Git is not compatible with normal use on cygwin
   if [[ $OSTYPE = cygwin ]]; then
     if git --version | grep msysgit > /dev/null; then
       echo "Error: Windows/MSYS Git is not supported on Cygwin"
       echo "Error: Make sure the Cygwin git package is installed and is first on the path"
-      exit 1
+      return 1
     fi
   fi
-  env git clone --depth=1 https://github.com/ohmybash/oh-my-bash.git "$OSH" || {
+  _omb_install_run env git clone --depth=1 https://github.com/ohmybash/oh-my-bash.git "$OSH" || {
     printf "Error: git clone of oh-my-bash repo failed\n"
-    exit 1
+    return 1
   }
 
   printf "${BLUE}Looking for an existing bash config...${NORMAL}\n"
   if [[ -f ~/.bashrc || -h ~/.bashrc ]]; then
-    printf "${YELLOW}Found ~/.bashrc.${NORMAL} ${GREEN}Backing up to ~/.bashrc.pre-oh-my-bash${NORMAL}\n";
-    mv ~/.bashrc ~/.bashrc.pre-oh-my-bash;
+    printf "${YELLOW}Found ~/.bashrc.${NORMAL} ${GREEN}Backing up to ~/.bashrc.pre-oh-my-bash${NORMAL}\n"
+    _omb_install_run mv ~/.bashrc ~/.bashrc.pre-oh-my-bash
   fi
 
   printf "${BLUE}Using the Oh My Bash template file and adding it to ~/.bashrc${NORMAL}\n"
-  cp "$OSH"/templates/bashrc.osh-template ~/.bashrc
+  _omb_install_run cp "$OSH"/templates/bashrc.osh-template ~/.bashrc
   sed "/^export OSH=/ c\\
 export OSH=$OSH
   " ~/.bashrc > ~/.bashrc-ombtemp
-  mv -f ~/.bashrc-ombtemp ~/.bashrc
+  _omb_install_run mv -f ~/.bashrc-ombtemp ~/.bashrc
+
+  set +e
 
   # MOTD message :)
   printf '%s' "$GREEN"
@@ -99,8 +166,20 @@ export OSH=$OSH
   printf '%s\n' '                        /____/                            .... is now installed!'
   printf "%s\n" "Please look over the ~/.bashrc file to select plugins, themes, and options"
   printf "${BLUE}${BOLD}%s${NORMAL}\n" "To keep up on the latest news and updates, follow us on GitHub: https://github.com/ohmybash/oh-my-bash"
-  exec bash; source ~/.bashrc
+
+  if [[ :$install_opts: == *:dry-run:* ]]; then
+    printf '%s\n' "$GREEN$BOLD[dryrun]$NORMAL Sample bashrc is created at '$BOLD$HOME/.bashrc-ombtemp$NORMAL'."
+  elif [[ :$install_opts: != *:unattended:* ]]; then
+    if [[ $- == *i* ]]; then
+      # In case install.sh is sourced from the interactive Bash
+      source ~/.bashrc
+    else
+      exec bash
+    fi
+  fi
 }
 
+[[ ${BASH_EXECUTION_STRING-} && $0 == -* ]] &&
+  set -- "$0" "$@"
 
-main
+_omb_install_main "$@" 5>&2