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This article mainly introduces what are the variables in the FOR command in DOS batch processing. It is very detailed and has a certain reference value. Friends who are interested must read it!

First, list all the variables in FOR:

~ I-remove any quotation marks ("), extend% I

% ~ fI-extends% I to a fully qualified pathname

% ~ dI-extends% I to only one drive letter

% ~ pI-extends% I to only one path

% ~ nI-extends% I to only one file name

% ~ xI-extends% I to only one file extension

% ~ sI-the extended path contains only short names

% ~ aI-extends% I to the file attributes of the file

% ~ tI-extends% I to the date / time of the file

% ~ zI-extends% I to the size of the file

% ~ $PATH:I-find the directory listed in the path environment variable and extend% I to the first fully qualified name found. If the environment variable name is not defined, or if the file is not found, this key combination is extended to an empty string

We can see that each line has an uppercase letter "I". This I is actually the variable we brought in in FOR. We will write here what the variable name is in our FOR statement.

For example: FOR / F% z IN ('set') DO @ echo% z

The name of the variable we substituted here is z, then we have to change that I to z, for example,% ~ fI to% ~ fz

As for the previous% ~ p, this kind of content is grammar!

Okay, let's start with:

1. ~ I-remove any quotation marks (") and extend% I

The function of this variable is just as he explained, delete the quotation marks!

Let's look at this example:

First, set up a temporary file temp.txt, which is as follows

"1111

"2222"

3333 "

"4444" 44

"55" 55

You can create a BAT file with the following code:

@ echo offecho ^ "1111 > temp.txtecho" 2222 "> temp.txtecho 3333 ^" > temp.txtecho "4444" 44 > > temp.txtecho ^ "55" 55 "55 > temp.txtrem creates a temporary file. Note that unpaired quotation marks should be escaped ^. Do not leave spaces FOR / F" delims= "% I IN (temp.txt) DO echo% ~ ipausedel temp.txt before redirection.

After execution, we see the echo of CMD as follows:

The quotation marks before the # string have been deleted

The quotation marks at the beginning and end of the # string have been deleted

3333 "# string is preceded by quotation marks, followed by quotation marks reserved

The quotation marks before the 4444 "44 # string are deleted, while the quotation marks in the middle are retained.

The quotation marks before the 55 "55" 55 # string are deleted, while the quotation marks in the middle are retained.

Please press any key to continue. . .

Compared with the previous temp.txt, we will find that the quotation marks on lines 1, 2, and 5 have disappeared, which is the purpose of deleting quotation marks ~ I!

The rules for deleting quotation marks are as follows (added by brother BAT!)

1. If there are quotation marks at the beginning and end of the string, delete the quotation marks at the beginning and the end of the string

2. If there are no quotation marks at the end of the string, delete the quotation marks at the beginning of the string

3. If there are quotation marks in the middle of the string, or if there are only quotation marks at the end, they are not deleted.

2.% ~ fI-extends% I to a fully qualified pathname

Look at the example:

Save the code anywhere, and I'll put it on the desktop here.

FOR / F "delims=="% I IN ('dir / b') DO @ echo% ~ fipause

After execution, the following is displayed:

Test.bat

Test.vbs

By comparison, we can easily see that there is no path, which is the function of "extending% I to a fully qualified path name", that is, if the content of the% I variable is a file name, he will print out the absolute path where the file is located, instead of just printing a file name, you will know under your own hands-on experiment!

3.% ~ dI-extend% I to only one drive letter

Look at the example:

The code is as follows, I will put it on the desktop for execution!

FOR / F "delims=="% I IN ('dir / b') DO @ echo% ~ dipause

After execution, my CMD shows the following

C:

C:

There are only two files on my desktop test.bat,test.vbs,%%~di function is that if the content of the variable% I is a file or directory name, he will put his file

Or the disk symbol where the directory is located is printed out!

4.% ~ pI-extend% I to only one path

This usage is the same as above, it only prints the path, not the file name.

FOR / F "delims=="% I IN ('dir / b') DO @ echo% ~ pipause

I will not play the results, you see the results, the following several are such a usage, the code is given, you see the results!

5.% ~ nI-extends% I to only one file name

Print only the file name

FOR / F "delims=="% I IN ('dir / b') DO @ echo% ~ nipause

6.% ~ xI-extend% I to only one file extension

Print only the file extension

FOR / F "delims=="% I IN ('dir / b') DO @ echo% ~ xipause

7.% ~ sI-the extended path contains only short names

Print an absolutely short file name

FOR / F "delims=="% I IN ('dir / b') DO @ echo% ~ sipause

8.% ~ aI-extends% I to the file attributes of the file

Properties of the print file

FOR / F "delims=="% I IN ('dir / b') DO @ echo% ~ aipause

9.% ~ tI-extends% I to the date / time of the file

Date on which the print file was created

FOR / F "delims=="% I IN ('dir / b') DO @ echo% ~ tipause

10.% ~ zI-extends% I to the size of the file

The size of the print file

FOR / F "delims=="% I IN ('dir / b') DO @ echo% ~ zipause

The "delims==" in the above example can be changed to "delims=", that is, no delimiter

% ~ $PATH:I-find the directory listed in the path environment variable and extend% I to the first fully qualified name found. If the environment variable name is not defined, or if the file is not found, this key combination is extended to an empty string

This is the last one, which is different from the ones above. I'll talk about it alone!

Then save the code as a batch and put it on the desktop.

@ echo offFOR / F "delims="% I IN ("notepad.exe") DO echo% ~ $PATH:ipause

Add: the above code shows the result as C:\ WINDOWS\ system32\ notepad.exe

He means to search the notepad.exe file in the path specified in the PATH variable, and if there is a notepad.exe, it will print out his absolute path, and if not, print an error!

All right, that's all for FOR's variables!

These are all the contents of the article "what are the variables in the FOR command in DOS batches?" Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

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