Mac OS X in a Nutshell

Name

if

Synopsis

                     if
                  

Begin a conditional statement. The simple format is:

if (expr) cmd

There are three other possible formats, shown side by side:

Example 1	Example 2	Example 3
if (expr) then cmds endif	if (expr) then cmds1 else cmds2 endif	if (expr) then cmds1 else if (expr) then cmds2 else cmds3 endif

In the simplest form, execute cmd if expr is true; otherwise do nothing (redirection still occurs; this is a bug). In the other forms, execute one or more commands. If expr is true, continue with the commands after then; if expr is false, branch to the commands after else (or branch to after the else if and continue checking). For more examples, see Section 21.5 earlier in this chapter, as well as the entries shift or while.

Example

Take a default action if no command-line arguments are given:

                     if ($#argv =  = 0) then
                      echo "No filename given. Sending to Report."
                        set outfile = Report
                     else
                        set outfile = $argv[1]
                     endif