中国DOS联盟

I want to display all current .txt files

@FOR /F "usebackq delims= tokens=*" %i IN (*.txt) DO @ECHO %i

This is wrong because the asterisk in the parentheses after in in for /f seems not to be able to be used as a wildcard. It is okay in for /d and for /r. I don't know if my understanding is correct?

So I adopted the following method

@FOR /F "usebackq delims= tokens=*" %i IN (`dir ^| find /i ".txt"`) DO @ECHO %i

This works, but there is a problem that files like a.txt.mp3 will also be displayed. Is there a better solution?

Last edited by tianlijian on 2007-3-18 at 03:18 PM ]

for /r .\ %a in (*.txt) do @echo %a

for /r .\ %a in (*.txt) do @echo %a

Brother lxmxn used it. The official explanation seems to be enumerating the current directory

@FOR /F "usebackq delims= tokens=*"  %i IN (`dir ^| find /i ".txt"`) DO @ECHO %i

In a Windows batch file, when you are using the `dir` command inside a `for /f` loop and you want to pass the `dir` command's output to `find`, the `|` character is a special character in the command line. To escape it so that it is passed correctly to the `for /f` loop's command execution, you need to use the caret (`^`) to escape it. So the `^|` is used to escape the pipe character so that it is treated as a literal character when the command is parsed within the `for /f` construct.

The original Chinese text's question is about why the `^` is used before the `|` in the given code. The translated explanation as above explains the reason for using `^` to escape the pipe character in the batch file context.
```code
@FOR /F "usebackq delims= tokens=*" %i IN (`dir ^| find /i ".txt"`) DO @ECHO %i
```
Why is the `^` used before the `|`? In a Windows batch file, when using the `dir` command within a `for /f` loop and redirecting the output with `|` to `find`, the `|` is a special character. To properly pass it through, the `^` is used to escape the `|` so that it is interpreted as a literal pipe character during command parsing within the `for /f` construct.

Originally posted by tianlijian at 2007-3-18 15:19:

@FOR /F "usebackq delims= tokens=*"  %i IN (`dir ^| find /i ".txt"`) DO @ECHO %i
Why is the ^ used before the |? 



　　The for command specifies that the redirection operators (> \ >> \ < \ |) in the parentheses after in need to be escaped, that is, a ^ is added in front of them to achieve escaping, otherwise an error will occur.

@FOR /F "tokens=*" %i IN ('dir *.txt') DO @ECHO %i

I understand the FOR statement as follows:
FOR /F only operates on strings, commands, and single files,
for /f .....in (" ") do ...
for /f .....in (file name) do ...
for /f .....in ('command') do ...

.```
for /r. %a in (*.txt) do @echo %a
```

Can the `\` after `.` be omitted?

Originally posted by logictianjin at 2007-4-6 22:36:
for /r . \
Can the backslash after . be omitted?

Why not just try it?

Originally posted by lxmxn at 2007-4-6 11:41 PM:


Why not just try it?

I think if you use for /r and the set contains wildcards, you can completely not use .\. If there are no wildcards in the set, it seems you need to add a dot. I don't know if my understanding is correct. I'm a beginner, please give me some advice.

Last edited by logictianjin on 2007-4-10 at 07:56 AM ]

I always can't fully understand the for / f.

I think for /r .\
This is probably the same as for /r . and both mean all subdirectories under this directory...
for /r \ means all directories under this drive
I don't know if my understanding is correct, please give guidance

. \ means the current directory and all its subdirectories, for example, dir .\ and you can see it.