Shell: How to append a prefix while looping through an array?
I'm trying t开发者_开发百科o loop through an array and append a prefix to each value in the array. Simplified version of the code:
#!/bin/sh
databases=( db1 db2 db3 )
for i in live_${databases[@]} stage_${databases[@]}
do
....
done
However, it only prepends the prefix to the first value in the array - the values it loops through are:
live_db1 db2 db3 stage_db1 db2 db3
Any thoughts? Thanks.
databases=( db1 db2 db3 )
for i in ${databases[@]/#/live_} ${databases[@]/#/stage_}
do
....
done
Try something like this:
#!/bin/sh
databases="db1 db2 db3"
for i in $databases
do
x="live_$i"
y="stage_$i"
echo "$x $y"
done
for i in $( for d in ${databases[@]}; do echo "live_$d stage_$d"; done )
do
....
done
Just adding to John Kugelman's answer. Details can be found in:
bash man page -> Parameter Expansion -> Pattern substitution
... If pattern begins with #, it must match at the beginning of the expanded value of parameter. ...
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