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    copied!<p>A Bash function can't return a string directly like you want it to. You can do three things:</p> <ol> <li>Echo a string</li> <li>Return an exit status, which is a number, not a string</li> <li>Share a variable</li> </ol> <p>This is also true for some other shells.</p> <p>Here's how to do each of those options:</p> <h2>1. Echo strings</h2> <pre><code>lockdir="somedir" testlock(){ retval="" if mkdir "$lockdir" then # Directory did not exist, but it was created successfully echo &gt;&amp;2 "successfully acquired lock: $lockdir" retval="true" else echo &gt;&amp;2 "cannot acquire lock, giving up on $lockdir" retval="false" fi echo "$retval" } retval=$( testlock ) if [ "$retval" == "true" ] then echo "directory not created" else echo "directory already created" fi </code></pre> <h2>2. Return exit status</h2> <pre><code>lockdir="somedir" testlock(){ if mkdir "$lockdir" then # Directory did not exist, but was created successfully echo &gt;&amp;2 "successfully acquired lock: $lockdir" retval=0 else echo &gt;&amp;2 "cannot acquire lock, giving up on $lockdir" retval=1 fi return "$retval" } testlock retval=$? if [ "$retval" == 0 ] then echo "directory not created" else echo "directory already created" fi </code></pre> <h2>3. Share variable</h2> <pre><code>lockdir="somedir" retval=-1 testlock(){ if mkdir "$lockdir" then # Directory did not exist, but it was created successfully echo &gt;&amp;2 "successfully acquired lock: $lockdir" retval=0 else echo &gt;&amp;2 "cannot acquire lock, giving up on $lockdir" retval=1 fi } testlock if [ "$retval" == 0 ] then echo "directory not created" else echo "directory already created" fi </code></pre>
 

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