Shift
Changes the position of batch parameters in a batch file.
Syntax
shift
Parameters
none
Remarks
Using the shift command-line option with command extensions
When command extensions are enabled (that is, the default), the shift command supports the /n command-line option, which tells the command to start shifting at the nth argument, where n can be a value from zero to eight. For example,
SHIFT /2
would shift %3 to %2, %4 to %3, and so on, and leave %0 and %1 unaffected.
How the shift command works
The shift command changes the values of the batch parameters %0 through %9 by copying each parameter into the previous one. In other words, the value of %1 is copied to %0, the value of %2 is copied to %1, and so on. This is useful for writing a batch file that performs the same operation on any number of parameters.
Working with more than 10 batch parameters
You can also use the shift command to create a batch file that can accept more than 10 batch parameters. If you specify more than 10 parameters on the command line, those that appear after the tenth (%9) will be shifted one at a time into %9.
Using %* with shift
Shift has no affect on the %* batch parameter.
Shifting parameters back
There is no backward shift command. After you carry out the shift command, you cannot recover the first batch parameter (%0) that existed before the shift.
Examples
The following batch file, Mycopy.bat, shows how to use shift with any number of batch parameters. It copies a list of files to a specific directory. The batch parameters are represented by the directory and file name arguments.
@echo off rem MYCOPY.BAT copies any number of files rem to a directory. rem The command uses the following syntax: rem mycopy dir file1 file2 ... set todir=%1 :getfile shift if "%1"=="" goto end copy %1 %todir% goto getfile :end set todir= echo All done
Formatting legend
Format |
Meaning |
|---|---|
Italic |
Information that the user must supply |
Bold |
Elements that the user must type exactly as shown |
Ellipsis (...) |
Parameter that can be repeated several times in a command line |
Between brackets ([]) |
Optional items |
Between braces ({}); choices separated by pipe (|). Example: {even|odd} |
Set of choices from which the user must choose only one |
Courier font |
Code or program output |