How to set PATH to another variable value with spaces in Windows batch file

Question

I've got a Windows batch script issue that I'm bashing my head against (no pun intended). The problematic script looks like this:

if defined _OLD_VIRTUAL_PATH (
    set PATH=%_OLD_VIRTUAL_PATH%
)

When I run it and _OLD_VIRTUAL_PATH is set I get:

\Microsoft was unexpected at this time.

_OLD_VIRTUAL_PATH is a variable that was originally set from PATH and it contains spaces - I'm pretty sure that's the problem. But what's the solution? It runs successfully if I enclose it in quotes, but I don't think the entire value of the PATH variable is supposed to be in quotes.

Answer 1

Your problem here are not the spaces but rather a closing parenthesis. You are probably running a 64-bit system where the Program Files directory for 32-bit applications is Program Files (x86). In a parenthesized block in a batch file, the closing parenthesis ends the block, so the rest of the line causes a syntax error.

You have two ways to fix this:

1) Put the complete set argument in quotes. This causes the closing paren to not be recognized as end of block:

if defined _OLD_VIRTUAL_PATH (
    set "PATH=%_OLD_VIRTUAL_PATH%"
)

2) Don't use a block:

if defined _OLD_VIRTUAL_PATH set PATH=%_OLD_VIRTUAL_PATH%