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| Batch display-suppression operator |
| o @ can be applied to any command as the first character on the command line in a batch program. |
| o It’s used to prevent an individual command from being displayed when it is executed. |
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| Batch file label operator |
| o : is used to identify a location in a batch file. It is not a command but a prefix of a label. |
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| o A label is a companion of the GOTO command. |
i.e. GOTO <label>
:<label> |
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| o A label is used to force MS-DOS to move to a specified location within the batch program. |
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| o Normally, when MS-DOS runs a batch program, it executes commands in the order as they appear in the program. However, when MS-DOS comes across the GOTO command (e.g. GOTO option1), it will move to the position that is identified by :option1 within the batch program. |
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| Batch replaceable parameter |
| o Consider the following commands frequently used at the DOS prompt:- |
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| ? copy autoexec.bat autoexec.bak |
| This command line creates a backup file of the autoexec.bat file. |
| copy is a command, autoexec.bat and autoexec.bak are parameters. These are required parameters. You must state both of them to make the command work. |
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| ? dir /w |
| This command line displays a directory entries of the current directory in wide screen format. dir is a command, /w is a parameter. It is an optional parameter for qualifying the output of the dir command. |
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| o Similarly, we can make use of parameters to help us achieve the same capability in executing a batch program. This way, we can execute the same batch program with different data at different time. They are called replaceable parameters. |
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| o %n and %%n are the special characters which represent the parameter in a batch program, where n is a single digit, from 1 through 9. |
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| o The replaceable parameters are positional. The digit, n, of the special characters represents the position of the parameter we type with the batch command. |
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| For example: |
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