====== Parameter Expansion ======

Apart from this page, we do now have pageset that discusses parameter expansion
in more detail. Please refer to [[scripting:paramexp|Scripting:Parameter Expansion]].

Substitutions tips

1. Use a variable name as reference to other variable\\ 
1.1 Numeric content

<code>
var1=5
tmp=var1
echo $((tmp))
</code>

1.2 All content

<code>
var=toto
tmp=var
echo ${(P)tmp}
</code>

Remove spaces from file names in the current directory (I replace them with underscores)

<code>
for file in *; do
  mv $file ${file:gs/\ /_/}
done
</code>

previous can also be done with zmv
<code>
zmv '(*)' '${1//\ /_/}'
</code>

Change filenames in current directory to lowercase

<code>
for file in *; do
  mv $file ${file//(#m)[A-Z]/${(L)MATCH}}
done
</code>

previous using zmv 
<code>
zmv '(*)' '${1:l}'
</code>