ShellExecute

I am using the ShellExecute command in a C++ program(Visual C++). I need
to send a parameter string that can be up to 700 characters long, but it
doesn't seem to execute unless the string is less than that. Does anyone
know of a maximum on the length of the parameter string that can be passed?

[jonnin]

Taking a stab, the limit may be with command.com, not shellex.
Can you send that many args to the program from a command prompt?
Shellexecute wants a char* (under a different name) and should not have a
size limit (maybe a fake one though ...)

if it works from the command prompt, then there is a limit. and if it works
with less than 700 as you said, then the limit is 699...

everyone has been saying use shellexecutex because shellexecute is flaky.
I used it and its fine under win98, but thats code just for my use ...



<pjohnson@e3corp.com> wrote:
>
>I am using the ShellExecute command in a C++ program(Visual C++). I need
>to send a parameter string that can be up to 700 characters long, but it
>doesn't seem to execute unless the string is less than that. Does anyone
>know of a maximum on the length of the parameter string that can be passed?

[Paul Kohlmiller]

If you get stuck on this, consider using a spawn function such as _spawnl()
<pjohnson@e3corp.com> wrote:
>
>I am using the ShellExecute command in a C++ program(Visual C++). I need
>to send a parameter string that can be up to 700 characters long, but it
>doesn't seem to execute unless the string is less than that. Does anyone
>know of a maximum on the length of the parameter string that can be passed?

[Danny Kalev]

typically, the limit is 254 characters + a terminating null. This is not
a standard requirement, just common practice. Perhaps you should pass a
filename as a parameter and store the actual string in the file. There
are other techniques but they are much more complicated and depend on
the compiler and platform you're using. For example, in Linux and Unix
you can use the exec() family of functions and pass a pointer to a
process' stack.

Danny

pjohnson@e3corp.com wrote:
>
> I am using the ShellExecute command in a C++ program(Visual C++). I need
> to send a parameter string that can be up to 700 characters long, but it
> doesn't seem to execute unless the string is less than that. Does anyone
> know of a maximum on the length of the parameter string that can be passed?

[Assaf Lavie]

The command.com program doesn't use ShellExecute, it uses CreateProcess.

As far as I can recall, there's not documented limit on the length of the
lpParameters argument.

Assaf.

"jonnin" <jonnin@vol.com> wrote in message news:3a562ef3$1@news.devx.com...
>
> Taking a stab, the limit may be with command.com, not shellex.
> Can you send that many args to the program from a command prompt?
> Shellexecute wants a char* (under a different name) and should not have a
> size limit (maybe a fake one though ...)
>
> if it works from the command prompt, then there is a limit. and if it
works
> with less than 700 as you said, then the limit is 699...
>
> everyone has been saying use shellexecutex because shellexecute is flaky.
> I used it and its fine under win98, but thats code just for my use ...
>
>
>
> <pjohnson@e3corp.com> wrote:
> >
> >I am using the ShellExecute command in a C++ program(Visual C++). I need
> >to send a parameter string that can be up to 700 characters long, but it
> >doesn't seem to execute unless the string is less than that. Does anyone
> >know of a maximum on the length of the parameter string that can be
passed?
>

Thanks for your response, but due to the limitations of the executable I am
trying to run, I have to do it the way I'm doing it. I tried cutting the
number of characters I was sending in lpParameters until I hit a magic number
where it quit. It turned out to be 493. Unfortunately, that won't work
for what I'm trying to do. I will have to explore other alternatives.