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when using $0 in my scripts, variable is replaced with whole invocation of the script with command line options and other parameters

No it's not. It's just the program name invoked.

$ cat a.pl #!/usr/bin/perl use feature qw( say ); say $0; $ pwd /home/ikegami $ perl a.pl foo a.pl $ perl ./a.pl foo ./a.pl $ perl /home/ikegami/a.pl foo /home/ikegami/a.pl $ perl "$HOME/a.pl" foo /home/ikegami/a.pl $ a.pl foo ./a.pl $ ./a.pl foo ./a.pl $ /home/ikegami/a.pl foo /home/ikegami/a.pl $ "$HOME/a.pl" foo /home/ikegami/a.pl

If you wanted to recreate the command, you could use

use String::ShellQuote qw( shell_quote ); my $cmd = shell_quote($0, @ARGV);
or
use String::ShellQuote qw( shell_quote ); my $cmd = shell_quote($^X, "--", $0, @ARGV);

Note that neither of these solutions will recreate options passed to perl rather than the script (such as -p, -C, etc.) Perl doesn't provide this information to the script.

Note that the command will be equivalent to the one used (subject to the aforementioned caveat), but it won't be a character for character match to what was used. For example, the exact quoting used may be different. There's no reliable way to get the command as entered because

  • there are multiple shells with different syntax, so there's no point in having the command as it was passed to the shell,

  • the command may have been part of larger command or used variables that are no longer accessible, so there's no point in having the command as it was passed to the shell, and

  • many programs aren't even launched from a shell!


In reply to Re: preserve quotes after $0 interpolation by ikegami
in thread preserve quotes after $0 + @ARGV interpolation by richard.sharpe

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