if-Linux Command

if

Conditionally perform a command.

SYNTAX
      if test-commands; then
      consequent-commands;
      [elif more-test-commands; then
      more-consequents;]
      [else alternate-consequents;]
      fi

The 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 `else alternate-consequents' 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.

Related commands:

case - Conditionally perform a command
eval - Evaluate several commands/arguments
expr - Evaluate expressions
for - Expand words, and execute commands
test - Evaluate a conditional expression
until - Execute commands (until error)
while - Execute commands