Pack bash initialization into an installed script

Issue: #17

README.md

@@ -170,48 +170,14 @@ if you want to use the capabilities of the _ai-cli_ library, configure your syst
 to use the Homebrew commands in preference to the ones supplied with macOS.
 
 ## Shell startup configuration
-You can configure the _ai-cli_ library to be always available in your _bash_ shell by
-adding the following lines in your `.bashrc` file.
-Adjust the `AI_CLI_LIB` setting to match the _ai-cli_ library installation path;
+You can configure the _ai-cli_ library to be always available in your _bash_
+shell by adding the following lines in your `.bashrc` file
+(ideally near its beginning for performance reasons).
+Adjust the provided path match the _ai-cli_ library installation path;
 it is currently set for a local installation in your home directory.
 ```bash
-# >>> initialize the ai-cli library >>>
-
-# Location of the ai-cli shared library; adjust as needed.
-AI_CLI_LIB=("$HOME/lib/ai_cli."*)
-
-# Execute only if configured, installed, and not initialized.
-if [[ -r ~/.aicliconfig && -r $AI_CLI_LIB && "$LD_PRELOAD" != *$AI_CLI_LIB* ]]
-then
-  # Set Linux and Cygwin environment variable.
-  if [ -z "$LD_PRELOAD" ] ; then
-    export LD_PRELOAD="$AI_CLI_LIB"
-  else
-    LD_PRELOAD="$LD_PRELOAD:$AI_CLI_LIB"
-  fi
-
-  # Set macOS environment variables.
-  if [ -z "$DYLD_LIBRARY_PATH" ] ; then
-    export DYLD_LIBRARY_PATH=/opt/homebrew/lib
-  else
-    DYLD_LIBRARY_PATH="/opt/homebrew/lib:$DYLD_LIBRARY_PATH"
-  fi
-  if [ -z "$DYLD_INSERT_LIBRARIES" ] ; then
-    export DYLD_INSERT_LIBRARIES="$AI_CLI_LIB"
-  else
-    DYLD_INSERT_LIBRARIES="$LD_PRELOAD:$AI_CLI_LIB"
-  fi
-
-  # Overlay current bash with a new instance, which will include the required
-  # environment variables.
-  if shopt -q login_shell ; then
-    exec -l bash
-  else
-    exec bash
-  fi
-
-fi
-# <<< initialize the ai-cli library <<<
+# Initialize the ai-cli library
+source $HOME/share/ai-cli/ai-cli-activate-bash.sh
 ```
 
 ## Reference documentation

src/Makefile

@@ -26,6 +26,7 @@ MANPREFIX ?= "$(PREFIX)/share/man/"
 SHAREPREFIX ?= "$(PREFIX)/share/ai-cli"
 
 PROGS=rl_driver $(SHARED_LIB)
+ACTIVATION_SCRIPTS=$(wildcard ai-cli-activate-*)
 RL_SRC=ai_cli.c config.c ini.c fetch_anthropic.c fetch_hal.c fetch_openai.c \
        fetch_llamacpp.c support.c
 TEST_SRC=$(wildcard *_test.c)
@@ -113,6 +114,9 @@ install: ai_cli.$(DLL_EXTENSION) # Help: Install library and manual pages
 	install -m 644 ai_cli.5 $(DESTDIR)$(MANPREFIX)/man5
 	install -m 644 ai_cli.7 $(DESTDIR)$(MANPREFIX)/man7
 	install -m 644 ai-cli-config $(DESTDIR)$(SHAREPREFIX)/config
+	for s in $(ACTIVATION_SCRIPTS) ; do \
+	  sed -e "s|__LIBPREFIX__|$(LIBPREFIX)|" $$s >$(DESTDIR)$(SHAREPREFIX)/$$s ; \
+	done
 
 help: # Help: Show this help message
 	@echo 'The following make targets are available.'

src/ai-cli-activate-bash.sh

@@ -0,0 +1,56 @@
+#
+# ai_cli - readline wrapper to obtain a generative AI suggestion
+#
+# Bash commands to activate ai-cli
+#
+# Copyright 2023-2024 Diomidis Spinellis
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+if [ "$0" != bash -a "$0" != -bash ] ; then
+  echo 'The ai-cli-lib activation script must be sourced, not executed.' 1>&2
+  exit 1
+fi
+
+AI_CLI_LIB=("__LIBPREFIX__/ai_cli."*)
+if [[ $- == *i*                                 # Shell is interactive
+  && -r ~/.aicliconfig                          # User has configured script
+  && -r $AI_CLI_LIB                             # Library installed
+  && "$LD_PRELOAD" != *$AI_CLI_LIB* ]]          # Variable not set
+then
+  # Linux and Cygwin (is also used for checking)
+  if [ -z "$LD_PRELOAD" ] ; then
+    export LD_PRELOAD="$AI_CLI_LIB"
+  else
+    LD_PRELOAD="$LD_PRELOAD:$AI_CLI_LIB"
+  fi
+
+  # macOS
+  if [ -z "$DYLD_LIBRARY_PATH" ] ; then
+    export DYLD_LIBRARY_PATH=/opt/homebrew/lib
+  else
+    DYLD_LIBRARY_PATH="/opt/homebrew/lib:$DYLD_LIBRARY_PATH"
+  fi
+  if [ -z "$DYLD_INSERT_LIBRARIES" ] ; then
+    export DYLD_INSERT_LIBRARIES="$AI_CLI_LIB"
+  else
+    DYLD_INSERT_LIBRARIES="$LD_PRELOAD:$AI_CLI_LIB"
+  fi
+
+  if shopt -q login_shell ; then
+    exec -l bash
+  else
+    exec bash
+  fi
+fi