check for bash features

This commit is contained in:
Kay Marquardt (Gnadelwartz) 2020-09-23 10:58:18 +02:00
parent 6718d24133
commit 1153d654d8
5 changed files with 86 additions and 46 deletions

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@ -94,6 +94,7 @@ Written by Drew (@topkecleon) and Kay M (@gnadelwartz).
<p>Uses <a href="http://github.com/dominictarr/JSON.sh">JSON.sh</a> and the magic of sed.</p>
<p>Even bashbot is written in bash, it depends on commands typically available in a Unix/Linux Environment. More concrete on the common commands provided by recent versions of <a href="https://en.wikipedia.org/wiki/List_of_GNU_Core_Utilities_commands">coreutils</a>, <a href="https://en.wikipedia.org/wiki/BusyBox#Commands">busybox</a> or <a href="https://landley.net/toybox/help.html">toybox</a>, see <a href="doc/7_develop.md#common-commands">Developer Notes</a></p>
<p><em>Note for MacOS and BSD Users:</em> As bashbot heavily uses modern bash and (gnu) grep/sed features, bashbot will not run without installing additional software, see <a href="doc/0_install.md">Install Bashbot</a></p>
<p><em>Note for emmbedded systems:</em> busybox or toybox ONLY is not sufficient, you need a to install a "real" bash, see <a href="doc/0_install.md">Install Bashbot</a></p>
<p>Bashbot <a href="https://github.com/topkecleon/telegram-bot-bash">Documentation</a> and <a href="https://github.com/topkecleon/telegram-bot-bash/releases">Downloads</a> are available on www.github.com</p>
<h2>Documentation</h2>
<ul>
@ -157,9 +158,11 @@ Written by Drew (@topkecleon) and Kay M (@gnadelwartz).
<p>To install and run bashbot you need access to a linux/unix command line. If you don't know how to get access to a linux/unix command line you should stop reading here :-(</p>
<p>In addition you need a <a href="https://telegram.org">Telegram client</a> and a mobile phone to <a href="https://telegramguide.com/create-a-telegram-account/">register an account</a>. If you don't want to register for Telegram you should stop reading here ;-)</p>
<p>After you're registered to Telegram send a message to <a href="https://telegram.me/botfather">@botfather</a>, <a href="doc/1_firstbot.md">create a new Telegram Bot token</a> and write it down. You need the token to install the bot.</p>
<p>Now open a terminal and check if bash is installed: <code>which bash &amp;&amp; echo "bash installed!"</code>. If you get an error message bash is not installed.</p>
<p>Now open a terminal and check if bash is installed:</p>
<pre><code>which bash &amp;&amp; echo &quot;bash seems available...&quot;
</code></pre>
<p>Create a new directory, change to it: <code>mkdir tbb; cd tbb</code> and download the latest '*.tar.gz' file from <a href="https://github.com/topkecleon/telegram-bot-bash/releases">https://github.com/topkecleon/telegram-bot-bash/releases</a>. This can be done with the commands:</p>
<div class="sourceCode" id="cb1"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb1-1" title="1"><span class="fu">wget</span> -q https://github.com/<span class="va">$(</span><span class="fu">wget</span> -q https://github.com/topkecleon/telegram-bot-bash/releases/latest -O - <span class="kw">|</span> <span class="fu">egrep</span> <span class="st">&#39;/.*/.*/.*tar.gz&#39;</span> -o<span class="va">)</span></a></code></pre></div>
<div class="sourceCode" id="cb2"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb2-1" title="1"><span class="fu">wget</span> -q https://github.com/<span class="va">$(</span><span class="fu">wget</span> -q https://github.com/topkecleon/telegram-bot-bash/releases/latest -O - <span class="kw">|</span> <span class="fu">egrep</span> <span class="st">&#39;/.*/.*/.*tar.gz&#39;</span> -o<span class="va">)</span></a></code></pre></div>
<p>Extract the '*.tar.gz' file and change to bashbot directory: <code>tar -xzf *.tar.gz; cd telegram-bot-bash</code>, install bashbot: <code>./bashbot.sh init</code> and enter your bot token when asked. All other questions can be answered by hitting the &lt;Return&gt; key.</p>
<p>That's all, now you can start your bot with <code>./bashbot.sh start</code> and send him messages:</p>
<pre><code>/start
@ -196,18 +199,18 @@ It features background tasks and interactive chats, and can serve as an interfac
<p>A powerful tool to improve your scripts is <code>shellcheck</code>. You can <a href="https://www.shellcheck.net/">use it online</a> or <a href="https://github.com/koalaman/shellcheck#installing">install shellcheck locally</a>. Shellcheck is used extensively in bashbot development to ensure a high code quality, e.g. it's not allowed to push changes without passing all shellcheck tests. In addition bashbot has a <a href="doc/7_develop.md">test suite</a> to check if important functionality is working as expected.</p>
<h3>Use printf whenever possible</h3>
<p>If you're writing a script and it is taking external input (from the user as arguments or file system...), you shouldn't use echo to display it. <a href="https://unix.stackexchange.com/a/6581">Use printf whenever possible</a></p>
<div class="sourceCode" id="cb4"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb4-1" title="1"> <span class="co"># very simple</span></a>
<a class="sourceLine" id="cb4-2" title="2"> <span class="bu">echo</span> <span class="st">&quot;text with variables. PWD=</span><span class="va">$PWD</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb4-3" title="3"> <span class="bu">printf</span> <span class="st">&#39;%s\n&#39;</span> <span class="st">&quot;text with variables. PWD=</span><span class="va">$PWD</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb4-4" title="4"> <span class="ex">-</span><span class="op">&gt;</span> text with variables. PWD=/home/xxx</a>
<a class="sourceLine" id="cb4-5" title="5"></a>
<a class="sourceLine" id="cb4-6" title="6"> <span class="co"># more advanced</span></a>
<a class="sourceLine" id="cb4-7" title="7"> <span class="va">FLOAT=</span><span class="st">&quot;1.2346777892864&quot;</span> <span class="va">INTEGER=</span><span class="st">&quot;12345.123&quot;</span></a>
<a class="sourceLine" id="cb4-8" title="8"> <span class="bu">echo</span> <span class="st">&quot;text with variabeles. float=</span><span class="va">$FLOAT</span><span class="st">, integer=</span><span class="va">$INTEGER</span><span class="st">, PWD=</span><span class="va">$PWD</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb4-9" title="9"> <span class="ex">-</span><span class="op">&gt;</span>text with variables. float=1.2346777892864, integer=12345.123, PWD=/home/xxx</a>
<a class="sourceLine" id="cb4-10" title="10"></a>
<a class="sourceLine" id="cb4-11" title="11"> <span class="bu">printf</span> <span class="st">&quot;text with variables. float=%.2f, integer=%d, PWD=%s\n&quot;</span> <span class="st">&quot;&quot;</span> <span class="st">&quot;</span><span class="va">$INTEGER</span><span class="st">&quot;</span> <span class="st">&quot;</span><span class="va">$PWD</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb4-12" title="12"> <span class="ex">-</span><span class="op">&gt;</span>text with variables. float=1.23, integer=12345, PWD=/home/xxx</a></code></pre></div>
<div class="sourceCode" id="cb5"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb5-1" title="1"> <span class="co"># very simple</span></a>
<a class="sourceLine" id="cb5-2" title="2"> <span class="bu">echo</span> <span class="st">&quot;text with variables. PWD=</span><span class="va">$PWD</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb5-3" title="3"> <span class="bu">printf</span> <span class="st">&#39;%s\n&#39;</span> <span class="st">&quot;text with variables. PWD=</span><span class="va">$PWD</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb5-4" title="4"> <span class="ex">-</span><span class="op">&gt;</span> text with variables. PWD=/home/xxx</a>
<a class="sourceLine" id="cb5-5" title="5"></a>
<a class="sourceLine" id="cb5-6" title="6"> <span class="co"># more advanced</span></a>
<a class="sourceLine" id="cb5-7" title="7"> <span class="va">FLOAT=</span><span class="st">&quot;1.2346777892864&quot;</span> <span class="va">INTEGER=</span><span class="st">&quot;12345.123&quot;</span></a>
<a class="sourceLine" id="cb5-8" title="8"> <span class="bu">echo</span> <span class="st">&quot;text with variabeles. float=</span><span class="va">$FLOAT</span><span class="st">, integer=</span><span class="va">$INTEGER</span><span class="st">, PWD=</span><span class="va">$PWD</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb5-9" title="9"> <span class="ex">-</span><span class="op">&gt;</span>text with variables. float=1.2346777892864, integer=12345.123, PWD=/home/xxx</a>
<a class="sourceLine" id="cb5-10" title="10"></a>
<a class="sourceLine" id="cb5-11" title="11"> <span class="bu">printf</span> <span class="st">&quot;text with variables. float=%.2f, integer=%d, PWD=%s\n&quot;</span> <span class="st">&quot;&quot;</span> <span class="st">&quot;</span><span class="va">$INTEGER</span><span class="st">&quot;</span> <span class="st">&quot;</span><span class="va">$PWD</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb5-12" title="12"> <span class="ex">-</span><span class="op">&gt;</span>text with variables. float=1.23, integer=12345, PWD=/home/xxx</a></code></pre></div>
<h3>Do not use #!/usr/bin/env bash</h3>
<p><strong>We stay with /bin/bash shebang, because it's more save from security perspective.</strong></p>
<p>Use of a fixed path to the system provided bash makes it harder for attackers or users to place alternative versions of bash and avoids using a possibly broken, mangled or compromised bash executable.</p>
@ -237,38 +240,38 @@ It features background tasks and interactive chats, and can serve as an interfac
<h3>Can I send messages from CLI and scripts?</h3>
<p>Of course, you can send messages from CLI and scripts, simply install bashbot as <a href="#Your-really-first-bashbot-in-a-nutshell">described here</a>, send the message '/start' to set yourself as botadmin and stop the bot with <code>./bashbot.sh stop</code>.</p>
<p>Run the following commands in your bash shell or script while you are in the installation directory:</p>
<div class="sourceCode" id="cb5"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb5-1" title="1"><span class="co"># prepare bash / script to send commands</span></a>
<a class="sourceLine" id="cb5-2" title="2"><span class="bu">export</span> <span class="va">BASHBOT_HOME=</span><span class="st">&quot;</span><span class="va">$(</span><span class="bu">pwd</span><span class="va">)</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb5-3" title="3"><span class="bu">source</span> ./bashbot.sh source</a>
<a class="sourceLine" id="cb5-4" title="4"></a>
<a class="sourceLine" id="cb5-5" title="5"><span class="co"># send me a test message</span></a>
<a class="sourceLine" id="cb5-6" title="6"><span class="ex">send_message</span> <span class="st">&quot;</span><span class="va">$(</span><span class="ex">getConfigKey</span> <span class="st">&quot;botadmin&quot;</span><span class="va">)</span><span class="st">&quot;</span> <span class="st">&quot;test&quot;</span></a>
<a class="sourceLine" id="cb5-7" title="7"></a>
<a class="sourceLine" id="cb5-8" title="8"><span class="co"># send me output of a system command</span></a>
<a class="sourceLine" id="cb5-9" title="9"><span class="ex">send_message</span> <span class="st">&quot;</span><span class="va">$(</span><span class="ex">getConfigKey</span> <span class="st">&quot;botadmin&quot;</span><span class="va">)</span><span class="st">&quot;</span> <span class="st">&quot;</span><span class="va">$(</span><span class="fu">df</span> -h<span class="va">)</span><span class="st">&quot;</span></a></code></pre></div>
<div class="sourceCode" id="cb6"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb6-1" title="1"><span class="co"># prepare bash / script to send commands</span></a>
<a class="sourceLine" id="cb6-2" title="2"><span class="bu">export</span> <span class="va">BASHBOT_HOME=</span><span class="st">&quot;</span><span class="va">$(</span><span class="bu">pwd</span><span class="va">)</span><span class="st">&quot;</span></a>
<a class="sourceLine" id="cb6-3" title="3"><span class="bu">source</span> ./bashbot.sh source</a>
<a class="sourceLine" id="cb6-4" title="4"></a>
<a class="sourceLine" id="cb6-5" title="5"><span class="co"># send me a test message</span></a>
<a class="sourceLine" id="cb6-6" title="6"><span class="ex">send_message</span> <span class="st">&quot;</span><span class="va">$(</span><span class="ex">getConfigKey</span> <span class="st">&quot;botadmin&quot;</span><span class="va">)</span><span class="st">&quot;</span> <span class="st">&quot;test&quot;</span></a>
<a class="sourceLine" id="cb6-7" title="7"></a>
<a class="sourceLine" id="cb6-8" title="8"><span class="co"># send me output of a system command</span></a>
<a class="sourceLine" id="cb6-9" title="9"><span class="ex">send_message</span> <span class="st">&quot;</span><span class="va">$(</span><span class="ex">getConfigKey</span> <span class="st">&quot;botadmin&quot;</span><span class="va">)</span><span class="st">&quot;</span> <span class="st">&quot;</span><span class="va">$(</span><span class="fu">df</span> -h<span class="va">)</span><span class="st">&quot;</span></a></code></pre></div>
<p>For more information see <a href="doc/8_custom.md">Expert Use</a></p>
<h3>Blocked by telegram?</h3>
<p>This may happen if to many or wrong requests are sent to api.telegram.org, e.g. using a invalid token or not existing API calls. If the block stay for longer time you can ask telegram service to unblock your IP-Adress.</p>
<p>You can check with curl or wget if you are blocked by Telegram:</p>
<div class="sourceCode" id="cb6"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb6-1" title="1"><span class="ex">curl</span> -m 10 https://api.telegram.org/bot</a>
<a class="sourceLine" id="cb6-2" title="2"><span class="co">#curl: (28) Connection timed out after 10001 milliseconds</span></a>
<a class="sourceLine" id="cb6-3" title="3"></a>
<a class="sourceLine" id="cb6-4" title="4"><span class="fu">wget</span> -t 1 -T 10 https://api.telegram.org/bot</a>
<a class="sourceLine" id="cb6-5" title="5"><span class="co">#Connecting to api.telegram.org (api.telegram.org)|46.38.243.234|:443... failed: Connection timed out.</span></a></code></pre></div>
<div class="sourceCode" id="cb7"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb7-1" title="1"><span class="ex">curl</span> -m 10 https://api.telegram.org/bot</a>
<a class="sourceLine" id="cb7-2" title="2"><span class="co">#curl: (28) Connection timed out after 10001 milliseconds</span></a>
<a class="sourceLine" id="cb7-3" title="3"></a>
<a class="sourceLine" id="cb7-4" title="4"><span class="fu">wget</span> -t 1 -T 10 https://api.telegram.org/bot</a>
<a class="sourceLine" id="cb7-5" title="5"><span class="co">#Connecting to api.telegram.org (api.telegram.org)|46.38.243.234|:443... failed: Connection timed out.</span></a></code></pre></div>
<p>Since Version 0.96 bashbot offers the option to recover from broken connections (aka blocked). Therefore you can provide a function named <code>bashbotBlockRecover()</code> in <code>mycommands.sh</code>. If the function exists it is called every time when a broken connection is detected.</p>
<p>Possible actions are: Check if network is working, change IP-Adress or simply wait some time.</p>
<p>If everything seems OK return 0 for retry or any non 0 value to give up.</p>
<div class="sourceCode" id="cb7"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb7-1" title="1"><span class="co"># called when bashbot sedn command failed because we can not connect to telegram</span></a>
<a class="sourceLine" id="cb7-2" title="2"><span class="co"># return 0 to retry, return non 0 to give up</span></a>
<a class="sourceLine" id="cb7-3" title="3"><span class="fu">bashbotBlockRecover()</span> <span class="kw">{</span></a>
<a class="sourceLine" id="cb7-4" title="4"> <span class="co"># place your commands to unblock here, e.g. change IP-Adess or simply wait</span></a>
<a class="sourceLine" id="cb7-5" title="5"> <span class="fu">sleep</span> 60 <span class="kw">&amp;&amp;</span> <span class="bu">return</span> 0 <span class="co"># may be temporary</span></a>
<a class="sourceLine" id="cb7-6" title="6"> <span class="bu">return</span> 1 </a>
<a class="sourceLine" id="cb7-7" title="7"> <span class="kw">}</span></a>
<a class="sourceLine" id="cb7-8" title="8"></a></code></pre></div>
<div class="sourceCode" id="cb8"><pre class="sourceCode bash"><code class="sourceCode bash"><a class="sourceLine" id="cb8-1" title="1"><span class="co"># called when bashbot sedn command failed because we can not connect to telegram</span></a>
<a class="sourceLine" id="cb8-2" title="2"><span class="co"># return 0 to retry, return non 0 to give up</span></a>
<a class="sourceLine" id="cb8-3" title="3"><span class="fu">bashbotBlockRecover()</span> <span class="kw">{</span></a>
<a class="sourceLine" id="cb8-4" title="4"> <span class="co"># place your commands to unblock here, e.g. change IP-Adess or simply wait</span></a>
<a class="sourceLine" id="cb8-5" title="5"> <span class="fu">sleep</span> 60 <span class="kw">&amp;&amp;</span> <span class="bu">return</span> 0 <span class="co"># may be temporary</span></a>
<a class="sourceLine" id="cb8-6" title="6"> <span class="bu">return</span> 1 </a>
<a class="sourceLine" id="cb8-7" title="7"> <span class="kw">}</span></a>
<a class="sourceLine" id="cb8-8" title="8"></a></code></pre></div>
<p>@Gnadelwartz</p>
<h2>That's it!</h2>
<p>If you feel that there's something missing or if you found a bug, feel free to submit a pull request!</p>
<h4>$$VERSION$$ v1.0-18-g9b3d689</h4>
<h4>$$VERSION$$ v1.0-21-g6718d24</h4>
</body>
</html>

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@ -18,6 +18,7 @@ More concrete on the common commands provided by recent versions of [coreutils](
*Note for MacOS and BSD Users:* As bashbot heavily uses modern bash and (gnu) grep/sed features, bashbot will not run without installing additional software, see [Install Bashbot](doc/0_install.md)
*Note for emmbedded systems:* busybox or toybox ONLY is not sufficient, you need a to install a "real" bash, see [Install Bashbot](doc/0_install.md)
Bashbot [Documentation](https://github.com/topkecleon/telegram-bot-bash) and [Downloads](https://github.com/topkecleon/telegram-bot-bash/releases) are available on www.github.com
@ -74,8 +75,11 @@ If you don't want to register for Telegram you should stop reading here ;-)
After you're registered to Telegram send a message to [@botfather](https://telegram.me/botfather),
[create a new Telegram Bot token](doc/1_firstbot.md) and write it down. You need the token to install the bot.
Now open a terminal and check if bash is installed: ```which bash && echo "bash installed!"```.
If you get an error message bash is not installed.
Now open a terminal and check if bash is installed:
```
which bash && echo "bash seems available..."
```
Create a new directory, change to it: ```mkdir tbb; cd tbb``` and download the latest '*.tar.gz' file from
[https://github.com/topkecleon/telegram-bot-bash/releases](https://github.com/topkecleon/telegram-bot-bash/releases). This can be done with the commands:
@ -261,4 +265,4 @@ bashbotBlockRecover() {
If you feel that there's something missing or if you found a bug, feel free to submit a pull request!
#### $$VERSION$$ v1.0-18-g9b3d689
#### $$VERSION$$ v1.0-21-g6718d24

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@ -29,6 +29,8 @@ Notes](doc/7_develop.md#common-commands)
grep/sed features, bashbot will not run without installing additional software,
see [Install Bashbot](doc/0_install.md)
*Note for emmbedded systems:* busybox or toybox ONLY is not sufficient, you
need a to install a "real" bash, see [Install Bashbot](doc/0_install.md)
Bashbot [Documentation](https://github.com/topkecleon/telegram-bot-bash) and
[Downloads](https://github.com/topkecleon/telegram-bot-bash/releases) are
@ -93,9 +95,11 @@ After you're registered to Telegram send a message to
[create a new Telegram Bot token](doc/1_firstbot.md) and write it down. You
need the token to install the bot.
Now open a terminal and check if bash is installed: ```which bash && echo "bash
installed!"```.
If you get an error message bash is not installed.
Now open a terminal and check if bash is installed:
```
which bash && echo "bash seems available..."
```
Create a new directory, change to it: ```mkdir tbb; cd tbb``` and download the
latest '*.tar.gz' file from
@ -351,4 +355,4 @@ wait
If you feel that there's something missing or if you found a bug, feel free to
submit a pull request!
#### $$VERSION$$ v1.0-18-g9b3d689
#### $$VERSION$$ v1.0-21-g6718d24

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@ -11,7 +11,7 @@
# This file is public domain in the USA and all free countries.
# Elsewhere, consider it to be WTFPLv2. (wtfpl.net/txt/copying)
#
#### $$VERSION$$ v1.0-18-g9b3d689
#### $$VERSION$$ v1.0-21-g6718d24
#
# Exit Codes:
# - 0 success (hopefully)
@ -22,8 +22,16 @@
# - 5 cannot connect to telegram bot
# - 6 mandatory module not found
# - 6 can't get bottoken
# - 10 not bash!
# shellcheck disable=SC2140,SC2031,SC2120,SC1091
# emmbeded system may claim bash but it is not
# check for bash like ARRAY handlung
if ! (unset a; set -A a a; eval "a=(a b)"; eval '[ -n "${a[1]}" ]'; ) > /dev/null 2>&1; then
echo "iError: Current shell does not support ARRAY's, may be busbox ash shell. pls install a real bash!";
exit 10
fi
# are we running in a terminal?
if [ -t 1 ] && [ -n "$TERM" ]; then
CLEAR='clear'
@ -34,6 +42,11 @@ if [ -t 1 ] && [ -n "$TERM" ]; then
NC='\e[0m'
fi
# we need some bash 4+ features, check for old bash by feature
if [ "$(echo -e "\u1111")" == "\u1111" ]; then
echo -e "${ORANGE}Warning: Unicode '\uxxxx' seems not supported, install a more current bash.${NC}"
fi
# some important helper functions
# returns true if command exist
_exists() {

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@ -1,5 +1,21 @@
#### [Home](../README.md)
## Check bash installation
There may be systems where bash seems to be installed but it is not, e.g. emmbedded systems, or the bash version is to old.
Run the following commands to see if your bash looks ok ...
```bash
# does the system say bash is there?
which bash && echo "bash seems available..."
# real bash supports ARRAY
bash -c 'eval "a=(1)" && echo "Shell supports ARRAY..."'
# check for ok version by feature
[ "$(echo "\u1111")" == "\u1111" ] && echo "Bash version may to old..."
```
## Install bashbot
1. Go to the directory you want to install bashbot, e.g.
@ -153,5 +169,5 @@ The old format is supported for backward compatibility, but may fail for corner
#### [Next Create Bot](1_firstbot.md)
#### $$VERSION$$ v1.0-20-gc292292
#### $$VERSION$$ v1.0-21-g6718d24