What is enabledelayedexpansion

Can be used to create subprograms: see Functions. Furthermore, can be used to enable delayed expansion like this: "setlocal EnableDelayedExpansion". Delayed expansion consists in the names of variables enclosed in exclamation marks being replaced with their values only after the execution reaches the location of their use rather than at an earlier point. The following is an example of using delayed expansion in a script that prints the specified number of first lines of a file, providing some of the function of the command "head" known from other operating systems:.

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BartoszKP Anthony Miller Anthony Miller Highly recommend it. Add a comment. Active Oldest Votes. This prints x2 and y2 : every 1 gets replaced by a 2. Improve this answer. Michel de Ruiter Michel de Ruiter 5, 5 5 gold badges 42 42 silver badges 62 62 bronze badges. To be clear, delayed expansion does nothing if no exclamation marks are present in your commands, right?

Exclamation marks do have other, subtle effects. Thanks again for the in depth explanation! Alex K. Well it would only have an adverse effect if you enabled it, then wrote some code that behaved differently were it not on — Alex K. And it seems that unfortunately there is no way to enable delayed expansion without invoking setlocal, even though these control what ought to be separate features.

We programmer just loves to keep it short Aacini Aacini With EnableDelayedExpansion you got even problems if your text contains only a single! Notice that within the for loop we use! Example of replacing one variable with values from another:.

If DelayedExpansion is processing a file with a! When DelayedExpansion is used inside a code block one or several commands grouped between parentheses whose output is Piped , the variable expansion will be skipped.