I am getting some data returned from a command line tool and would like to fill an associative array with the data. I can alter the format of the data returned, but how must it be to the associative array?
content="[key1]=val1 [key2]=val2" # How should this be formatted?
declare -A hashTable
hashTable=($content) # How to set it?
declare -p hashTable
The best way to do this (which requires bash 4.4 or later) is to have your command return a string alternating keys and values, each terminated by a null character. You can then use readArray to parse this into an indexed array, then build your associative array from that.
$ readArray -t -d '' foo < <(printf 'key1\0value1\0key2\0value2\0')
$ declare -p foo
declare -a foo=([0]="key1" [1]="value1" [2]="key2" [3]="value2")
$ for ((i=0; i < ${#foo[@]}; i+=2)); do
> hashTable[${foo[i]}]=${foo[i+1]}
> done
$ declare -p hashTable
declare -A hashTable=([key2]="value2" [key1]="value1" )
bash 4.4 is required for the -d option to readArray. In earlier 4.x releases, you can use a string with embedded newlines, but that precludes your keys or values from themselves containing newlines.
(Note that in the assignments to hashTable, you can safely leave both ${foo[i]} and ${foo[i+1]} unquoted, as neither the key nor the value will undergo word splitting or pathname expansion. It doesn't hurt to quote them if you wish, though.)
If you master content and understand well bash parsing, for example not coming from exernal input
eval "hashTable=($content)"
otherwise you have to parse it to ensure no injection (as eval reinterpret data as code, bash expression), imagine content contains echo given as example
content=');echo hey;x=('
maybe easier to split the content :
hashTable=()
tmp=$content
while [[ $tmp = *\[* ]] && tmp=${tmp#*\[} || tmp=; [[ $tmp ]]; do
cur=${tmp%%\[*};
val=${cur#*\]=};
hashTable[${cur%%\]=*}]=${val%${val##*[![:space:]]}}
done
If you accept to format the output of the first command like this
key1=value1 key2=value2
without spaces in value2 and without '=', then you can try this code:
#!/bin/bash
content="key1=val1 key2=val2"
declare -A hashTable
for pair in $content ; do
key=${pair%=*} # take the part of the string $pair before '='
value=${pair/#*=/} # take the part of the string $pair after '='
hashTable[$key]=$value
done
for K in "${!hashTable[@]}"; do echo hashTable\[$K\]=${hashTable[$K]}; done
$content is not going to be safe.