Commodore PC - Page 185

Batch Processing 113 |
n
[\
' '
if
Purpose:
Performs a command based on the result of a condition.
Syntax:
if [NOT] error level number command
or
if [NOT] stringl = = string2 command
or
if [NOT] exist filename command
Comments:
The if statement allows conditional execution of commands.
When the condition is true, ms-dos executes the command, other
wise it ignores the command.
The conditions are described as follows:
errorlevel number
True if, and only if, the previous program executed by
command.com had an exit code of number or higher. (When a
program finishes, it returns an exit code via ms-dos.) You can use
this condition to perform other tasks that are based on the previ
ous program's exit code.
stringl = = string2
True if, and only if, stringl and string2 are identical after parame
ter substitution. Strings may not contain separators, such as com
mas, semicolons, equal signs, or spaces.
exist filename
True if, and only if, filename exists.
If you specify the NOT parameter, ms-dos executes the command
when the condition is false.
Example:
The following example prints the message "can't find datafile"
if the file productdat does not exist on the disk:
if
i
Displaying a
conditional message
if not exist product.dat echo can't find datafile