Unable to acces "$?" environment variable

[Yevgen Reznichenko]

Hello,

i want to use kdialog from my perl script. The return code of kdialog is
stored in the variable $?, but i an unable to access this:

my $result = $ENV{'\?'};
print "--> $result";

cause following warning:

Use of uninitialized value in concatenation (.) or string at
programs/mails_pop3.pl line 49, <FILE> line 1.
-->

if i print all available env variables, with:

foreach $key (sort(keys %ENV)) {
print "$key = $ENV{$key}\n";
}

so $? will not be listed. Do you know how i can get access to this variable?

Regards,

Yevgen

 

[Tony Curtis]

Hello, i want to use kdialog from my perl script. The
return code of kdialog is stored in the variable $?, but
i an unable to access this:

my $result = $ENV{'\?'}; print "--> $result";

$? is not an environment variable. It's a variable
maintained by various shells to record the exit behaviour
of sub-processes.

You want to fork into the command and then examine the
exit status of the child process.

perldoc -f system

shows you how.

hth
t

 

[Steve Grazzini]

i want to use kdialog from my perl script. The return code of
kdialog is stored in the variable $?, but i an unable to access
this:

my $result = $ENV{'\?'};
print "--> $result";

It's not an environment variable.

print "--> $?";

Check "perlvar" and the docs for system() or backticks or whatever
you were using to invoke kdialog.

 

[Yevgen Reznichenko]

Am 01.11.2003 19:09 schrieb Steve Grazzini:

It's not an environment variable.

print "--> $?";

Many thanks, it works now fine.

Regards,

Yevgen

 

[Eric J. Roode]

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Hash: SHA1

Hello,

i want to use kdialog from my perl script. The return code of kdialog
is stored in the variable $?, but i an unable to access this:

my $result = $ENV{'\?'};
print "--> $result";

Others have explained to you that $? is not an environment variable as
such, and therefore cannot be accessed via %ENV.

However: Why did you put a backslash before the question mark above?
That, combined with the single quotes, means you were trying to look up an
environment variable called \? -- two characters, a backslash and a
question mark.

- --
Eric
$_ = reverse sort $ /. r , qw p ekca lre uJ reh
ts p , map $ _. $ " , qw e p h tona e and print

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[Yevgen Reznichenko]

Am 01.11.2003 20:52 schrieb Eric J. Roode:

my $result = $ENV{'\?'};
print "--> $result";

[...]
However: Why did you put a backslash before the question mark above?

It was an error, i was trying to escape "?" in the hope that it will
then works, but i doesn't and i forgot to delete them.

Regards,

Yevgen