in reply to system() and qx comparison

Remove the single quotes from around $LANG in your second form or replace them with double quotes.

qx is another form for backticks, which in perl will capture the return from the system call.

my $return = qx{echo $LANG};
say $return;

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Re^2: system() and qx comparison
by didess (Sexton) on Sep 27, 2011 at 22:28 UTC
    thanks for your answer;

    but, if replace single quotes by doubles quotes with qx, $LANG will be resolved as a Perl variable, not as a shell environment variable

    This little code will show it clearly: 
    cat essaiQX.pl
#!/usr/bin/perl 

my $LANG = "script internal";

system('echo $LANG');
system('echo','$LANG');

my @out = qx "echo $LANG";
chomp(@out);
print "out=@out\n";

my @out = qx' echo $LANG ';
chomp(@out);
print "out=@out\n";

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    it's output is : 

    ./essaiQX.pl
fr_FR.UTF-8
$LANG
out=script internal
out=fr_FR.UTF-8

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    In fact i'd like to pass parameters to the command (the "echo" program in this little example), with possibly $, *, and such characters which the shell interpretes. while avoiding a large collection of antislashes. May be, it's not possible with qx and I must use system(). That's what I'd like to know</p

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      If you want the environments LANG variable, use $ENV{LANG}.
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