我们可以在perl脚本中创建bash实例吗？

Question

I am trying to use Perl to create a process running bash and then create a file sample.txt , but after the bash command I can't see any output on the console or any sample.txt file in the same directory structure. Can somebody help me to fix following code?

my $var = `bash -l`;
system($var);
print "Done!";

my $filename = 'sample.txt';
open(my $fh, '>', $filename) or die "Could not open file '$filename' $!";
chmod(0777, "sample.txt");
print $fh "hello";
close $fh;
print "Done 1!..";

Answer 1

Bash's -l argument is convincing it to stay interactive. Running:

perl -e 'print `bash -l`'

On its own has the bash process bound to stdin interactively, but the subprocess's output is captured by perl and printed later when bash exits, which it will only do when you press Control D , issue exit or logout etc.

You probably wanted to start with $var = 'bash -l'; . That will start bash interactively at first, and when you exit, will continue the remainder of the program. To me it's unusual to want to do this and I expect you should write something for bash that exits normally, probably with the -c argument.

Replacing your first two lines of code with:

 system("bash", "-c", "echo Hello World!");

accomplishes this and the remainder of the program executes normally. I'm unsure what you wanted bash to do for you however. These example cases would be better accomplished with just
system("echo", "Hello World!") or print "Hello World!" .