Hi.  I have a bonehead question.  I'm just trying to do a simple
cmd script using an IF statement.  Why doesn't the code below work?

                   Thanks, Alan

set retry = 0

if retry = 0 echo Hello

On Mar 10, 4:41 pm, Alan <jalantho***@verizon.net> wrote:
Type IF/? at the command prompt.  Also, don't use spaces in batch,
unless they are absolutely necessary.  For example, your SET statement
creates a variable named 'retry ' (no quotes).  That is, the name
includes the space before the equal sign.  In batch, the IF test is C-
like in that the equivalence operator is == (two equal signs).
Finally, an environment variable is indicated by enclosing its name in
percent signs.  So, the correct syntax is ...

set retry=0

if %retry%==0 echo Hello

Unfortunately, there is still a problem here, but it's not directly
related to the syntax.  Rather, the subtler than that.  The problem
will only arise in the instance that the variable RETRY fails to be
defined at teh time of the test.  In that case, the command looks like
this ...

if ==0 echo Hello

which does create a syntax error.  A common solution is to add one or
more dummy characters to both sides of the equal signs, as in ...

if [%retry%]==[0] echo Hello

then in the event RETRY is undefined (empty) the statement is
evaluated as ...

if []==[0] echo Hello

which remains syntactically correct and evaluates as a false
condition.

HTH,

Tom Lavedas
***********
http://there.is.no.more/tglbatch/

Try this:

@echo off
set retry=0
if retry==0 echo Hello

Note the absence of spaces around the = and the doubling of the = symbol.

Show quote Hide quote Or try this:

    @echo off
    set/a retry = 0
    if "%retry%" EQU "0" echo/Hello

/Al

Thank you all.  Spaces were my problem.     Alan

OK.  This is driving me nuts. . . .

     I have the following code in a large CMD file:

.. . .
set retry=0

    if [%retry%]==[1] GoTo NewName
.. . .
     This code is a fragment of code in a for loop.  It was not
working, so I wrote out to a log file.  It shows:

set retry=0
if [] == [1] GoTo NewName

I already checked the spacing.

      HOWEVER, just to be that much more irritating, when I put the
code fragment (copied from the original) as follows in a separate CMD
file, it works!

set retry=0

    if [%retry%]==[1] GoTo NewName
    echo Not retrying . . .
    set retry=1
    GoTo _ProcNames

echo Processing NEW name . . .

PAUSE
exit

     Any idea what is going on???????      Thanks in advance, Alan

On Mar 11, 8:09 pm, Alan <jalantho***@verizon.net> wrote:
Show quoteHide quoteI was stumped for a minute until I found a clue.  The clue is your
statement that this "code in a for loop"!  Then I knew what the
problem is. It is that environment variables are evaluated only once
when the code of a FOR loop is first parsed, unless a special
formulation is employed.  This is called 'delayed expansion'.  It is
explained in, of all places, the help to the SET statement, though
there is a reference in the SETLOCAL statements help (but not a word
in the help to the FOR):

quote
Delayed environment variable expansion allows you to use a different
character (the exclamation mark) to expand environment variables at
execution time.  If delayed variable expansion is enabled, the above
examples could be written as follows to work as intended:

    set VAR=before
    if "%VAR%" == "before" (
        set VAR=after
        if "!VAR!" == "after" @echo If you see this, it worked
    )

    set LIST=
    for %i in (*) do set LIST=!LIST! %i
    echo %LIST%
end quote

Invoking delayed expansion requires the following rather wordy
statement ...

setlocal enabledelayedexpansion

So try this and see if it doesn't fix things...

setlocal enabledelayedexpansion
for ... in (...) do (...
set retry=0

    if [!retry!]==[1] GoTo NewName
    echo Not retrying . . .
    set retry=1
    GoTo _ProcNames

echo Processing NEW name . . .

)

Tom Lavedas
=========

Tom,
         There is already a "setlocal enabledelayedexpansion"
statement at the beginning of the CMD file.  I just did not know it
was important.

    However, when I changed "if [%retry%]==[1] GoTo NewName" to "if [!
retry!]==[1] GoTo NewName" then it appears to work.  I thought the
output log would show something like "if [0]==[1].  However, it showed
"if [!retry!]==[1]" instead.  That appears to indicate that it is
being evaluated now.  The branching did work.

      Thank you very much.  If you know where I can buy a decoder
ring, please let me know.

Alan

SBS 2003 VB Scripting - Help Needed!
modify incremental_backup
Script to set share permissions on home directories
Change Password
LDAP query fails... because of parentheses?
Script for Thunderbird configuration
Undefined variable in login script
Scruot to check user rights on folders/subfolders
Script to find the presence of a software
startup scripting