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    <p>Edit: added timing comparisons (at end) and got rid of the <code>tr</code></p> <p>It is possible to <em>replace</em> the content of array elements using bash <em><a href="http://wiki.bash-hackers.org/syntax/pe" rel="nofollow">Parameter expansion</a></em>, ie. <code>${var[@]....}</code> but you cannot actually <em>delete</em> the elements. The best you can get with parameter expansion is to make null ("") those elements you do not want. </p> <p>Instead, you can use <code>printf</code> and <code>sed</code>, and <code>IFS</code>. This has the advantabe of allowing you to use full regular expression syntax (not just the shell globbing expressions)... and it is <em>much</em> faster than using a loop... </p> <p>This example leaves array elements which contain <code>c</code><br> <strong>Note:</strong> This method caters for spaces in data. This is achieved via <code>IFS=\n</code> </p> <pre><code>IFS=$'\n'; a=($(printf '%s\n' "${a[@]}" |sed '/c/!d')) </code></pre> <p>Here it is again with before/after dumps: </p> <pre><code>#!/bin/bash a=(one.ac two.b tree.c four.b "five b abcdefg" ) echo "======== Original array ====" printf '%s\n' "${a[@]}" echo "======== Array containing only the matched elements 'c' ====" IFS=$'\n'; a=($(printf '%s\n' "${a[@]}" |sed '/c/!d')) printf '%s\n' "${a[@]}" echo "========" </code></pre> <p>Output: </p> <pre><code>======== Original array ==== one.ac two.b tree.c four.b five b abcdefg ======== Array containing only the matched elements 'c' ==== one.ac tree.c five b abcdefg ======== </code></pre> <hr> <p>For general reference: Testing an array containing 10k elements. selecting 5k: </p> <pre><code>a=( a\ \ \ \ b{0..9999} ) </code></pre> <p> The printf method took: <code>0m0.226s</code> (results in sequential index values)<br>     The first loop method: <code>0m4.007s</code> (it leaves gaps in index values)<br> The second loop method: <code>0m7.862s</code> (results in sequential index values) </p> <p>printf method: </p> <pre><code>IFS=$'\n'; a=($(printf '%s\n' "${a[@]}" |sed '/.*[5-9]...$/!d')) </code></pre> <p>1st loop method: </p> <pre><code>iz=${#a[@]}; j=0 for ((i=0; i&lt;iz; i++)) ;do [[ ! "${a[i]}" =~ .*[5-9]...$ ]] &amp;&amp; unset a[$i] done </code></pre> <p>2nd loop method: </p> <pre><code>iz=${#a[@]}; j=0 for ((i=0; i&lt;iz; i++)) ;do if [[ ! "${a[i]}" =~ .*[5-9]...$ ]] ;then unset a[$i] else a[$j]="${a[i]}=$i=$j"; ((j!=i)) &amp;&amp; unset a[$i]; ((j+=1)); fi done </code></pre>
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