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POHow to get exit status of piped command from inside the pipeline?
 

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  1. POHow to get exit status of piped command from inside the pipeline?
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    <p>Consider I have following commandline: <code>do-things arg1 arg2 | progress-meter "Doing things...";</code>, where <code>progress-meter</code> is bash function I want to implement. It should print <code>Doing things...</code> before running <code>do-things arg1 arg2</code> or in parallel (so, it will be printed anyway at the very beginning), and record stdout+stderr of <code>do-things</code> command, and check it's exit status. If exit status is 0, it should print <code>[ OK ]</code>, otherwise it should print <code>[FAIL]</code> and dump recorded output.</p> <p>Currently I have things done using <code>progress-meter "Doing things..." "do-things arg1 arg2";</code>, and <code>eval</code>uating second argument inside, which is clumsy and I don't like that and believe there is better solution.</p> <p>The problem with pipe syntax is that I don't know how can I get <code>do-things</code>' exit status from <strong>inside</strong> the pipeline? <code>$PIPESTATUS</code> seems to be useful only after <strong>all</strong> commands in pipeline finished.</p> <p>Maybe process substitution like <code>progress-meter "Doing things..." &lt;(do-things arg1 arg2);</code> will be fine, but in this case I also don't know how can I get exit status of <code>do-things</code>.</p> <p>I'll be happy to hear if there is some other neat syntax possible to achieve same task without escaping command to be executed like in my example.</p> <p>I greatly hope for the help of community.</p> <p><i><strong>UPD1:</strong> As question seems not to be clear enough, I paraphrase it:</i></p> <p>I want bash function that can be fed with command, that will execute in parallel to function, and bash function will receive it's stdout+stderr, wait for completion and get its exit status.</p> <p>Example implementation using <code>eval</code>s:</p> <pre><code>progress_meter() { local output; local errcode; echo -n -e $1; output=$( { eval "${cmd}"; } 2&gt;&amp;1; ); errcode=$?; if (( errcode )); then { echo '[FAIL]'; echo "Output was: ${output}" } else { echo '[ OK ]'; }; fi; } </code></pre> <p>So this can be used as <code>progress_meter "Do things..." "do-things arg1 arg2"</code>. I want the same without eval.</p>
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      1. POHow to get exit status of piped command from inside the pipeline?
      1. USunutbu
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    1. COthanks for fixes, Emil, but using "evil" instead of "eval" was intentional though.
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