Batch file commands display variable

Batch has poison characters. Open a cmd prompt and type your batch file name - you will see any error messages then. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually. In this tutorial, you will learn about batch file commands and how they are used in batch file scripting or programming.

As discussed in the previous tutorial, a batch file is an unformatted text file or script file which contains multiple batch file commands or instructions to achieve a certain task. It has extension of. Click here to go through the introduction of the batch file before learning batch file commands. For the ease of learning, we have listed all the batch file commands with relevant examples and explanations below.

Please click on the commands to know the details. If only ASSOC is written and executed, it will display all the file associations for every extension, instead of just. The batch command ATTRIB is used to display the file attributes or set an attribute to a file in the working directory.

Now let us suppose we have a file note. We will display its file attributes and then make it hidden and read only by adding 'ah' and 'r' attributes to it. And finally, we will remove some attributes we added as well. The batch command CD helps in navigating through different directories and changing directories or displaying current directory. The batch command COMP compares the size of two files and checks if they are different in size.

This script will ask for users permission to check the properties of disk partition and if allowed, will display following output in the console depending on disk properties. This output shows the fraction of drivers list with their properties and installed date.

The "script" in this context being a line - or block - of code, surrounded by round brackets:. In the above example, the ECHO command is evaluated as Hello when the script is read into memory, so the script will echo Hello forever, however many passes are made through the script. The way to achieve the more "traditional" variable behaviour of the variable being expanded whilst the script is running is to enable "delayed expansion". This involves adding that command into the script prior to the loop instruction usually a FOR loop, in a batch script , and using an exclamation mark!

Now, an advanced technique. Using the CALL command allows the batch command processor to expand a variable located on the same line of the script. This can deliver multilevel expansion, by repeated CALL and modifier use.

This is useful in, for example, a FOR loop. As in the following example, where we have a numbered list of variables:. Note that the variable! This is double expansion of the variable i. Thus it increases to 2 on the 2nd pass through the loop, and to 3 on the 3rd pass.