In addition to backticks `command`, command substitution can be done with $(command) or "$(command)", which I find easier to read, and allows for nesting.
OUTPUT="$(ls -1)" echo "${OUTPUT}" MULTILINE=$(ls \ -1) echo "${MULTILINE}" Quoting (") does matter to preserve multi-line values; it is optional on the right-hand side of an assignment, as word splitting is not performed, so OUTPUT=$(ls -1) would work fine.
