result of system call
 

Hi there,

I'm using the system() function to call a program but would like to
get the result of this operation.

system returns an int depending on weather the command was executed
successfully of not.

How can I get a string -- or array of strings with the output of the
camming line application instead?

Thanks

Karl

Re: result of system call
 

"budgie" <larrylarrigan@yahoo.com> wrote in message
news:75511ff7.0310090143.1cafb322@posting.google.c om...
> [...]
> How can I get a string -- or array of strings with the output of
> the camming line application instead?

You would need to redirect the output of the application.
On many systems, there is a fork() function, or something
similar. In this way, your program can call another process
and control several features, such as the I/O.

Dave



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Re: result of system call
 

Hi,

Use
popen( "command", "r" );

then read from the returned descriptor. This method is one way either you
read or write, but it is less code than fork.

Regards, Ron AF Greve.



"budgie" <larrylarrigan@yahoo.com> wrote in message
news:75511ff7.0310090143.1cafb322@posting.google.c om...
> Hi there,
>
> I'm using the system() function to call a program but would like to
> get the result of this operation.
>
> system returns an int depending on weather the command was executed
> successfully of not.
>
> How can I get a string -- or array of strings with the output of the
> camming line application instead?
>
> Thanks
>
> Karl

Re: result of system call
 

Moonlit wrote:
> Hi,
>
> Use
> popen( "command", "r" );
>
> then read from the returned descriptor. This method is one way either
> you read or write, but it is less code than fork.

Neither popen, nor fork is a standard C or C++ function. They are POSIX
functions, off-topic here. But that is not the point: since they aren't C
and C++ functions it is nice to mention that fact once you post them into a
C++ newsgroup.

--
WW aka Attila

Re: result of system call
 

budgie wrote:
> Hi there,
>
> I'm using the system() function to call a program but would like to
> get the result of this operation.
>
> system returns an int depending on weather the command was executed
> successfully of not.
>
> How can I get a string -- or array of strings with the output of the
> camming line application instead?
>
> Thanks
>
> Karl
maybe
char * d << system("yukk.exe");
might work
but then it probably will not
but you could make it work with:
my_string x << system("yukk.exe");
but probably not, because standard out is standard out

Re: result of system call
 

"klaas" <jan@zonnet.ru> wrote in message news:UKihb.11381$732.1216351@zonnet-reader-1...

> maybe
> char * d << system("yukk.exe");
> might work
> but then it probably will not
> but you could make it work with:
> my_string x << system("yukk.exe");
> but probably not, because standard out is standard out

System doesn't return strings. System returns a single int.
If the argument is other than a null pointer, the value of this
single int is implementation-defined.

It's not a bunch of strings reflecting the output of the command
invoked in any case.

You will have to do this in a system dependent fashion. If you
are on a UNIX/POSIX system, try popen.