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    <p>After each command, the exit code can be found in the <code>$?</code> variable so you would have something like:</p> <pre><code>ls -al file.ext rc=$?; if [[ $rc != 0 ]]; then exit $rc; fi </code></pre> <p>You need to be careful of piped commands since the <code>$?</code> only gives you the return code of the last element in the pipe so, in the code:</p> <pre><code>ls -al file.ext | sed 's/^/xx: /" </code></pre> <p>will not return an error code if the file doesn't exist (since the <code>sed</code> part of the pipeline actually works, returning 0).</p> <p>The <code>bash</code> shell actually provides an array which can assist in that case, that being <code>PIPESTATUS</code>. This array has one element for each of the pipeline components, that you can access individually like <code>${PIPESTATUS[0]}</code>:</p> <pre><code>pax&gt; false | true ; echo ${PIPESTATUS[0]} 1 </code></pre> <p>Note that this is getting you the result of the <code>false</code> command, not the entire pipeline. You can also get the entire list to process as you see fit:</p> <pre><code>pax&gt; false | true | false; echo ${PIPESTATUS[*]} 1 0 1 </code></pre> <p>If you wanted to get the largest error code from a pipeline, you could use something like:</p> <pre><code>true | true | false | true | false rcs=${PIPESTATUS[*]}; rc=0; for i in ${rcs}; do rc=$(($i &gt; $rc ? $i : $rc)); done echo $rc </code></pre> <p>This goes through each of the <code>PIPESTATUS</code> elements in turn, storing it in <code>rc</code> if it was greater than the previous <code>rc</code> value.</p>
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    1. COSame feature in just one line of portable code: `ls -al file.ext || exit $?` ( [[ ]] is not portable )
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    2. COMarcH, I think you'll find that `[[ ]]` is pretty portable in `bash`, which is what the question is tagged :-) Strangely enough, `ls` doesn't work in `command.com` so it's not portable either, specious I know, but it's the same sort of argument you present.
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    3. COI know this is ancient, but it should be noted that you can get the exit code of commands in a pipe via the array `PIPESTATUS` (i.e., `${PIPESTATUS[0]}` for the first command, `${PIPESTATUS[1]}` for the second, or `${PIPESTATUS[*]}` for a list of all exit stati.
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