Written by Barry Dysert (last updated December 20, 2021)
As you get more comfortable typing at the command prompt, you may want to explore what the For loop can do for you. Fundamentally, the For loop lets you execute commands over a set of items like files or directories. So, for example, if you want to perform the same activity over a set of files, using a For loop can provide tremendous time savings.
The general form of a For loop is:
FOR %variable IN (set) DO command [command-parameters]
Where "%variable" can be anything from "%a" through "%z"; the "set" is the list of space-separated file names on which you want to perform the "command"; and the "command-parameters" are an optional list of parameters to accompany the "command".
As an example, if you wanted to display to the screen the contents of files a.txt, b.txt, and c.txt you could do so using the following For loop:
FOR %i IN (a.txt b.txt c.txt) DO TYPE %i
If you have command extensions enabled, there are some additional forms of the For loop:
FOR /D %variable IN (set) DO command [command-parameters]
In this form, if "set" contains a wildcard character then it represents directories instead of files.
FOR /R [[drive:]path] %variable IN (set) DO command [parameters]
In this form, the loop walks the directory tree specified by "[[drive:]path]", executing the FOR statement in each directory along the path.
FOR /L %variable IN (start,stop,end) DO command [parameters]
In this form, the set is a sequence of numbers from "start" to "end", by "step" amount.
FOR /F ["options"] %variable IN (set) DO command [parameters]
In this form, "set" is one or more file names. Each file is opened, read, and processed before going on to the next file in "set". This particular form is quite powerful when "options" are specified. Details and examples can be found by typing "FOR /?" at the command line.
This tip (13118) applies to Windows 7, 8, and 10.
There are times when you might need to know how many files or subfolders are in a folder. Using the command prompt, you ...Discover More
If your computer is set up in crowded environment, it may be helpful to establish times that an account can be used. You ...Discover More
If you have Wi-Fi connection problems, Windows 10 can provide a report to help diagnose possible issues. Using Command ...Discover More
There are currently no comments for this tip. (Be the first to leave your comment—just use the simple form above!)