China DOS Union

For example, to run a software on a removable disk, but the drive letter will be different on different machines!

```
set a=%0
echo %a:~0,2%>temp.txt
```

It still doesn't seem to work!

Try again: (Write the following content into a BAT file to execute)
set a=%~0
echo %a:~0,2%>temp.txt
Or use the following code:
echo %~d0>temp.txt

Thanks, moderator. It's already okay.

Regarding the acquisition of the current drive letter, there are generally the following three schemes:

1. cd command:
@echo off echo Current path is: %cd% echo Current drive letter is: %cd:~0,1% pause

2. for statement extension:
@echo off for %%i in (.) do set var=%%~di echo Current drive letter is: %var:~0,1% pause

3. Parameter %~0 scheme:
@echo off set a=%~0 echo Current drive letter is: %a:~0,1% pause

Of course, there are other schemes. Generally, they all use the for statement to extract the characters at the specific position of the return value, and without exception, they all need to be implemented by intercepting characters (The statement in blue is not completely accurate. For specific situations, please refer to the example in 11F).

[ Last edited by namejm on 2006-11-24 at 08:58 PM ]

%~0 does not get the current path with quotes

Originally posted by Must Love at 2006-11-17 18:38:
%~0 doesn't get the quoted current path啊

　　Hehe, sorry, I made a mistake, I was missing a ~ symbol.

Of course, there are other solutions. Generally, for statements are used to extract characters at specific positions in the return value, and without exception, they all need to be implemented by intercepting characters.

It seems there can be an exception. I don't know if this works?

@echo off set a=%~d0 echo Current drive letter is: %a::=% pause

The %a::=% statement is to achieve by removing the colon in the display result, essentially it is still intercepting the characters at specific positions.

Inspired by the following post, another method to get the current drive letter was discovered.
Asking willsort and all brothers about prompt _$T$_

The code is as follows:

1. @echo off
   
2. for /f "usebackq skip=1 eol=;" %%i in (`"echo exit|%comspec% /k prompt $N$_;"`) do set "d=%%i"
   
3. echo The current drive letter is: %d%
   
4. pause
   

hxuan?表ｰ： 2006-11-24 15:13

There are also the following codes, which can output the current drive letter, current path, current date, current time, and version number, and can also output your personalized DOS prompt.

1. @echo off
   
2. for /f "usebackq skip=1 eol=; delims=" %%i in (`"echo exit|%comspec% /k prompt $N$_;"`) do set "aaa=%%i"
   
3. echo %aaa%
   
4. for /f "usebackq skip=1 eol=; delims=" %%i in (`"echo exit|%comspec% /k prompt $D$_;"`) do set "aaa=%%i"
   
5. echo %aaa%
   
6. for /f "usebackq skip=1 eol=; delims=" %%i in (`"echo exit|%comspec% /k prompt $E$_;"`) do set "aaa=%%i"
   
7. echo %aaa%
   
8. for /f "usebackq skip=1 eol=; delims=" %%i in (`"echo exit|%comspec% /k prompt $P$_;"`) do set "aaa=%%i"
   
9. echo %aaa%
   
10. for /f "usebackq skip=1 eol=; delims=" %%i in (`"echo exit|%comspec% /k prompt $T$_;"`) do set "aaa=%%i"
    
11. echo %aaa%
    
12. for /f "usebackq skip=1 eol=; delims=" %%i in (`"echo exit|%comspec% /k prompt $V$_;"`) do set "aaa=%%i"
    
13. echo %aaa%
    
14. pause
    

hxuan?表ｰ： 2006-11-24 15:19

[ Last edited by hxuan999 on 2006-12-13 at 11:40 AM ]

The `prompt` is a relatively niche command, but it has such a powerful function, which is worthy of attention from everyone. Nice nice, give hxuan999 plus points reward.

Appreciate it~~
Brother hxuan999 has really rich imagination~ : )

The `prompt` command is relatively niche, yet it has such powerful functions, which is worthy of everyone's attention. Not bad, give hxuan999 a bonus.

Sweat, think about the DOS/9x batch processing in the past, almost all were dominated by `prompt`, and there were tons of related skills

You can also start a new special thread for discussing Prompt techniques, which can not only carry forward the techniques but also earn more points~ Haha...