If you are new to Bot development read [Bots: An introduction for developers](https://core.telegram.org/bots) and consult [Telegram Bot API Documentation](https://core.telegram.org/bots/api/).
In addition you should know about [BotFather, the one bot to rule them all](https://core.telegram.org/bots#3-how-do-i-create-a-bot). It will help you create new bots and change settings for existing ones. [Commands known by Botfather](https://core.telegram.org/bots#generating-an-authorization-token)
If you dont't have a github account, it may time to [sepup a free account now](https://github.com/pricing)
### Add commands to mycommands.sh only
To ease updates never change ```bashbot.sh```, instead your commands and functions must go to ```mycommands.sh``` . Insert your Bot commands in the ```case ... esac``` block of the 'mycommands()' function:
```bash
# file: mycommands.sh
# your additional bahsbot commands
# uncomment the following lines to overwrite info and help messages
bashbot_info='This is *MY* variant of _bashbot_, the Telegram bot written entirely in bash.
'
bashbot_help='*Available commands*:
/echo message - _echo the given messsage_
'
# NOTE: command can have @botname attached, you must add * in case tests...
mycommands() {
case "$MESSAGE" in
'/echo'*) # example echo command
send_normal_message "${CHAT[ID]}" "$MESSAGE"
;;
# .....
esac
}
```
### Reuse or disable global commands
If you want to disable or reuse a global bashbot command comment it out in 'commands.sh' by placing a '#' in front of
every line from ```'/command')``` to ```;;```.
**Learn more about [Bot commands](https://core.telegram.org/bots#commands).**
**Note: Never disable the catchall command ```*)``` in 'commands.sh'!!**
```bash
# file: commands.sh
case "$MESSAGE" in
################################################
# GLOBAL commands start here, edit messages only
#'/start'*)
# send_action "${CHAT[ID]}" "typing"
# _is_botadmin && _markdown_message "You are *BOTADMIN*."
# if _is_allowed "start" ; then
# _markdown_message "${bot_help}"
# else
# _message "You are not allowed to start Bot."
# fi
# ;;
*) # forward other messages to optional dispatcher
If a command need more than 2-3 lines of code, you should use a function to seperate logic from command. Place your functions in ```mycommands.sh``` and call the from your command. Example:
```bash
# file: mycommands.sh
# your additional bahsbot commands
mycommands() {
case "$MESSAGE" in
'/process'*) # logic for /process is done in process_message
result="$(process_message "$MESSAGE")"
send_normal_message "${CHAT[ID]}" "$result"
;;
esac
}
# place your functions here
process_message() {
local ARGS="${1#/* }" # remove command
local TEXT OUTPUT=""
# process every word in MESSAGE, avoid globbing
set -f
for WORD in $ARGS
do
# process links
if [[ "$WORD" == "https://"* ]]; then
REPORT="$(dosomething_with_link "$WORD")"
# no link, add as text
else
TEXT="$(echo "${TEXT} $WORD")"
continue
fi
# compose result
OUTPUT="* ${REPORT} ${WORD} ${TEXT}"
TEXT=""
done
# return result, reset globbing in case we had no ARGS
echo "${OUTPUT}${TEXT}"
}
```
### Test your Bot with shellcheck
Shellcheck is a static linter for shell scripts providing excellent tips and hints for shell coding pittfalls. You can [use it online](https://www.shellcheck.net/) or [install it on your system](https://github.com/koalaman/shellcheck#installing).
All bashbot scripts are linted by shellcheck.
Shellcheck examples:
```bash
$ shellcheck -x mybotcommands.inc.sh
Line 17:
TEXT="$(echo "${TEXT} $WORD")"
^-- SC2116: Useless echo? Instead of 'cmd $(echo foo)', just use 'cmd foo'.
```
As you can see my ```mybotcommands.inc.sh``` contains an useless echo command in 'TEXT=' assigment and can be replaced by ```TEXT="${TEXT}${WORD}"```
```bash
$ shellcheck -x examples/notify
OK
$ shellcheck -x examples/question
OK
$ shellcheck -x commands.sh
OK
$ shellcheck -x bashbot.sh
In bashbot.sh line 123:
text="$(echo "$text" | sed 's/ mynewlinestartshere /\r\n/g')" # hack for linebreaks in startproc scripts
^-- SC2001: See if you can use ${variable//search/replace} instead.
^-- SC2034: CONTACT appears unused. Verify it or export it.
```
The example show two warnings in bashbots scripts. The first is a hint you may use shell substitions instead of sed, this is fixed and much faster as the "echo | sed" solution.
The second warning is about an unused variable, this is true because in our examples CONTACT is not used but assigned in case you want to use it :-)
