Thread: EDB installer should check for valid %COMSPEC%

Hi folks

Some recent discussion on Stack Overflow has revealed another exciting
way for Windows computers to be subtly broken.

For as yet unknown reasons - probably related to security/virus scanner
software, since everything else seems to be - some Windows machines have
an invalid COMSPEC environment variable.

Two variants have been sighted in the wild:

    %SystemRoot%\system32\cmd.exe;

(note the trailing semicolon), and:

    C:\Windows\System32

Both will produce the delightfully helpful initdb failure:

    initdb: could not execute command ""C:/Program
Files/PostgreSQL/9.2/bin/postgres.exe" --boot -x1 -F ": No error

while running:

    cscript //NoLogo "C:\Program
Files\PostgreSQL\9.2/installer/server/initcluster.vbs" "NT
AUTHORITY\NetworkService" "postgres" "****" "C:\Program
Files\PostgreSQL\9.2" "C:\Program Files\PostgreSQL\9.2\data" 5432 "DEFAULT"

which will exit with:

    Script exit code: 1

In the one I was looking into, fixing COMSPEC in the System control
panel's Environment Variables page by removing the trailing semicolon
corrected the issue. It can be verified as correct by opening a new
command prompt after you've changed the variable (not just re-using an
existing already-open one) and running:

    "%COMSPEC%" /C "echo test ok"

which should print:

    test ok

not something like:

    '"C:\Windows\System32\cmd.exe;"' is not recognized as an internal or
external command,
operable program or batch file."



Since I can find several reports of this spanning over a couple of
years, I'd love to see a test for this integrated into the EDB
installer. Just verify that popen() actually works before running the
initdb script, and if it doesn't, check %COMSPEC% to see if it really
points to cmd.exe .

--
 Craig Ringer                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Hi

On Mon, Nov 19, 2012 at 4:29 AM, Craig Ringer <craig@2ndquadrant.com> wrote:
> Hi folks
>
> Some recent discussion on Stack Overflow has revealed another exciting
> way for Windows computers to be subtly broken.
>
> For as yet unknown reasons - probably related to security/virus scanner
> software, since everything else seems to be - some Windows machines have
> an invalid COMSPEC environment variable.
>
> Two variants have been sighted in the wild:
>
>     %SystemRoot%\system32\cmd.exe;
>
> (note the trailing semicolon), and:
>
>     C:\Windows\System32
>
> Both will produce the delightfully helpful initdb failure:
>
>     initdb: could not execute command ""C:/Program
> Files/PostgreSQL/9.2/bin/postgres.exe" --boot -x1 -F ": No error
>
> while running:
>
>     cscript //NoLogo "C:\Program
> Files\PostgreSQL\9.2/installer/server/initcluster.vbs" "NT
> AUTHORITY\NetworkService" "postgres" "****" "C:\Program
> Files\PostgreSQL\9.2" "C:\Program Files\PostgreSQL\9.2\data" 5432 "DEFAULT"
>
> which will exit with:
>
>     Script exit code: 1
>
> In the one I was looking into, fixing COMSPEC in the System control
> panel's Environment Variables page by removing the trailing semicolon
> corrected the issue. It can be verified as correct by opening a new
> command prompt after you've changed the variable (not just re-using an
> existing already-open one) and running:
>
>     "%COMSPEC%" /C "echo test ok"
>
> which should print:
>
>     test ok
>
> not something like:
>
>     '"C:\Windows\System32\cmd.exe;"' is not recognized as an internal or
> external command,
> operable program or batch file."
>
>
>
> Since I can find several reports of this spanning over a couple of
> years, I'd love to see a test for this integrated into the EDB
> installer. Just verify that popen() actually works before running the
> initdb script, and if it doesn't, check %COMSPEC% to see if it really
> points to cmd.exe .

Interesting - thanks for the info Craig. Sandeep; can you please look
into adding such a check to the installer. We already test the
VBscript interpreter, so this should go in the same place.

--
Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

check %COMSPEC% to see if it really
> points to cmd.exe .

Interesting - thanks for the info Craig. Sandeep; can you please look
into adding such a check to the installer. We already test the
VBscript interpreter, so this should go in the same place.

-- Craig Ringer                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services