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copied!<p>You can further modify the hput()/hget() interface so that you have named hashes as follows:</p> <pre><code>hput() { eval "$1""$2"='$3' } hget() { eval echo '${'"$1$2"'#hash}' } </code></pre> <p>and then</p> <pre><code>hput capitals France Paris hput capitals Netherlands Amsterdam hput capitals Spain Madrid echo `hget capitals France` and `hget capitals Netherlands` and `hget capitals Spain` </code></pre> <p>This lets you define other maps that don't conflict (e.g., 'rcapitals' which does country lookup by capital city). But, either way, I think you'll find that this is all pretty terrible, performance-wise.</p> <p>If you really want fast hash lookup, there's a terrible, terrible hack that actually works really well. It is this: write your key/values out to a temporary file, one-per line, then use 'grep "^$key"' to get them out, using pipes with cut or awk or sed or whatever to retrieve the values.</p> <p>Like I said, it sounds terrible, and it sounds like it ought to be slow and do all sorts of unnecessary IO, but in practice it is very fast (disk cache is awesome, ain't it?), even for very large hash tables. You have to enforce key uniqueness yourself, etc. Even if you only have a few hundred entries, the output file/grep combo is going to be quite a bit faster - in my experience several times faster. It also eats less memory.</p> <p>Here's one way to do it:</p> <pre><code>hinit() { rm -f /tmp/hashmap.$1 } hput() { echo "$2 $3" >> /tmp/hashmap.$1 } hget() { grep "^$2 " /tmp/hashmap.$1 | awk '{ print $2 };' } hinit capitals hput capitals France Paris hput capitals Netherlands Amsterdam hput capitals Spain Madrid echo `hget capitals France` and `hget capitals Netherlands` and `hget capitals Spain` </code></pre>

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