Performs conditional processing in batch programs. IF NOT ERRORLEVEL number command IF NOT string1=string2 command IF NOT ...

Performs conditional processing in batch programs.  IF [NOT] ERRORLEVEL number command IF [NOT] string1==string2 command IF [NOT] EXIST filename command    NOT               Specifies that Windows should carry out                     the command only if the condition is false.    ERRORLEVEL number Specifies a true condition if the last program run                     returned an exit code equal to or greater than the number                     specified.    string1==string2  Specifies a true condition if the specified text strings                     match.    EXIST filename    Specifies a true condition if the specified filename                     exists.    command           Specifies the command to carry out if the condition is                     met.  Command can be followed by ELSE command which                     will execute the command after the ELSE keyword if the                     specified condition is FALSE  The ELSE clause must occur on the same line as the command after the IF.  For example:      IF EXIST filename. (         del filename.     ) ELSE (         echo filename. missing.     )  The following would NOT work because the del command needs to be terminated by a newline:      IF EXIST filename. del filename. ELSE echo filename. missing  Nor would the following work, since the ELSE command must be on the same line as the end of the IF command:      IF EXIST filename. del filename.     ELSE echo filename. missing  The following would work if you want it all on one line:      IF EXIST filename. (del filename.) ELSE echo filename. missing