The Command Combination Symbols

Windows allows you to enter multiple commands on a single command line. Furthermore, you can make later commands depend on the results of earlier commands. This feature can be particularly useful in batch programs and Doskey macros, but you might also find it convenient at the command prompt.

To simply combine commands without regard to their results, use the ampersand (&) symbol:

If the first command fails (because there is no File.dat on drive F, for example), the second command is unlikely to work as you expect. Windows provides two command symbols for better control over situations like this:

• The && symbol causes the second command to run only if the first command succeeds.
• The || symbol causes the second command to run only if the first command fails.

Consider this modified version of the earlier example:

With this command line, if the Copy command fails, the Edit command is ignored.

Sometimes you want the opposite effect-execute the second command only if the first fails:

This command line tries to copy the file from drive F. If that doesn't work, it tries to copy the file from drive G.