SC2207

Prefer mapfile or read -a to split command output (or quote to avoid splitting).

Problematic code:

array=( $(mycommand) )

Correct code:

If it outputs multiple lines, each of which should be an element:

# For bash 4.x
mapfile -t array < <(mycommand)

# For bash 3.x+
array=()
while IFS='' read -r line; do array+=("$line"); done < <(mycommand)

# For ksh
array=()
mycommand | while IFS="" read -r line; do array+=("$line"); done

If it outputs a line with multiple words (separated by spaces, other delimiters can be chosen with IFS), each of which should be an element:

# For bash
IFS=" " read -r -a array <<< "$(mycommand)"

# For ksh
IFS=" " read -r -A array <<< "$(mycommand)"

If the output should be a single element:

array=( "$(mycommand)" )

Rationale:

You are doing unquoted command expansion in an array. This will invoke the shell's sloppy word splitting and glob expansion.

Instead, prefer explicitly splitting (or not splitting):

• If you want to split the output into lines or words, use mapfile, read -ra and/or while loops as appropriate.
• If the command output should become a single array element, quote it.

This prevents the shell from doing unwanted splitting and glob expansion, and therefore avoiding problems with output containing spaces or special characters.

Exceptions:

If you have already taken care (through setting IFS and set -f) to have word splitting work the way you intend, you can ignore this warning.