Windows echo command can't echo a user-set variable

What did I do to开发者_运维技巧 screw up my CMD shell? Windows XP Pro, open a cmd window and do:

C:\>set tt = name

C:\>set tt
tt = name

C:\>echo %tt%
%tt%

C:\>echo %time%
14:13:28.67

The echo command doesn't work for some reason. I can echo the built-in variables just fine. Tried it on another computer and that works as expected

The set command does not take spaces. The proper syntax would be:

set tt=name

What you have done in your example is set an environment variable tt<space>. With that in mind, you can try this:

echo %tt %

and see your output.

The most upvoted answer here, accepted far ago, claims that:

"The set command does not take spaces."

But that is not correct: The %tt % variable actually works: It can be set and referenced. (Despite it is confusing.)

Problem reproduced:

Indeed, on my Win7:

C:\>set os
OS=Windows_NT

C:\>set tt = name
C:\>set tt2= name
C:\>set tt3=name
C:\>set tt
tt = name
tt2= name
tt3=name

I tried and got:

C:\>echo "%os%"
"Windows_NT"

C:\>echo "%tt3%"
"name"
C:\>echo "%tt2%"
" name"
C:\>echo "%tt%"
"%tt%"

Resolved cases:

The intuitively expected variable %tt% is not set. But %tt % is set instead:

C:\>echo "%tt %"
" name"

Even more, with a space at the end of the value, set tt4 = name :

C:\>echo "%tt4 %"
" name "

Conclusions:

The set command does not trim():

• The space before "=" is included to the var_name .
• The space after "=" is included to the var_value.
• The space at the end of the var_value is included to it.

On the other hand:

• The space at the beginning of the var_name is not included to it, which is rather normal for command line arguments in general.

Have you tried setting the variable with no space between the equals? (set tt=name)