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Re: [PATCH] Fix parameter passing containing quote/equal to Windows batch command


On 1/20/2014 1:02 AM, Daniel Dai wrote:
We notice one issue when running a Windows batch command inside
cygwin. Here is one example.

Simple batch file:
a.bat:
echo %1

Run it under cygwin:
./a.bat a=b
a

./a.bat "a=b"
a

If we pass additional \"
./a.bat "\"a=b\""
"\"a

There seems no way to pass a=b into bat.

This is how batch files work, and likely not a problem with Cygwin:
http://support.microsoft.com/kb/35938
Excerpt: "it is not possible to include an equal sign as an argument to a batch file"

Be careful to note that cmd.exe and .bat files naturally split a=b into two arguments and strip out the equals sign:

(Run from cmd.exe)
C:\>Argecho.bat a=b
FIRST a
SECOND b
THIRD

I did notice that adding double quotes (in cmd.exe) will make will it arrive as one argument, and note that the double quotes are still there:

(Run from cmd.exe)
C:\>Argecho.bat "a=b"
FIRST "a=b"
SECOND
THIRD

There is a problem getting Cygwin the above test case, however.

The test script was:
C:\>type Argecho.bat
@echo off
echo FIRST %1
echo SECOND %2
echo THIRD %3

When run from Cygwin bash, and you force the double quotes by surrounding double quotes "a=b" with single quotes '"a=b"', you seem to get too *many* quotes in the batch file:

(Run from bash, the batch file behaves correctly as if run from cmd.exe)
$ Argecho.bat a=b
FIRST a
SECOND b
THIRD

(Run from bash, same as above since bash removes the double quotes prior to passing to program):
$ Argecho.bat "a=b"
FIRST a
SECOND b
THIRD

(Run from bash, this is what is surprising double surrounded with single)
$ Argecho.bat '"a=b"'
FIRST "\"a
SECOND b\""
THIRD

It seems that only the final test case above doesn't behave as expected.


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