Conditionally perform a command.
if test-commands; then
[elif more-test-commands; then
fiThe test-commands list is executed, and if its return status is zero, the consequent-commands list is executed.
If test-commands returns a non-zero status, each elif list is executed in turn, and if its exit status is zero, the corresponding more-consequents is executed and the command completes.
If &qt;else alternate-consequents&qt;&qt; is present, and the final command in the final if or elif clause has a non-zero exit status, then alternate-consequents is executed.
The return status is the exit status of the last command executed, or zero if no condition tested true.