Perl one-liner Quotes help

[Anonymous Monk]

I want my Perl one-liner to print quotes. See my attempts below.

$ perl -lane "print 'hello ''  ' "
$ perl -lane 'print "hello ''  "   -- this seems to be waiting for som
+ething.
$ perl -lane 'print "hello \'\'  " -- this also seems to be waiting fo
+r something.

TIA.

[ikegami]

It helps to mention which shell you're using if you us to help with its quoting mechanism. Looks like bash or similar.

You want bash to do

system(
    q{perl},
    q{-lane},
    q{print "John's";},
);

The first two parts are no-brainers since they contain no characters that are special to bash. Let's focus on the third.

• You could escape every special character

  print\ \"John\'s\";
  

• You could use double quotes and escape the characters that are special in double quotes.

  "print \"John's\";"
  

• You can't use single quotes, at least not alone. There's no way to include single quotes in a single-quoted bash literal. What you can do is use different mechanisms for different parts of the string (as in q{print "John}.q{'}.q{s";})

  'print "John'"'"'s";'
  'print "John'\''s";'
  

So

perl -lane 'print "John'\''s";'

Note that the following is also acceptable to Perl:

system(
    q{perl},
    q{-lane}.q{print "John's";},
);

That could be written as

perl '-laneprint "John'\''s";'

but it looks better as

perl -lane'print "John'\''s";'

[johngg]

You can use hex escapes inside a double-quote quoting construct (qq{...}). Works on *nix and Windows.

$ perl -le 'print qq{hello \x27\x22  \x22\x27};'
hello '"  "'
$

C:\>perl -le "print qq{hello \x27\x22  \x22\x27};"
hello '"  "'
C:\>

I hope this is useful.

[alexbio]

In the second and third examples, you forgot a final '

If you want ' print working try

perl -e "print 'hello \'\'  ' "

or

perl -e "print \"hello \'\'  \" "

(Like the first example but with \')

The second and third, wait for something because they (with -lane) mean

BEGIN { $/ = "\n"; $\ = "\n"; }
LINE: while (defined($_ = <ARGV>)) {
    chomp $_;
    our(@F) = split(' ', $_, 0);
    print 'hello   ';
}

Update: Just inverted order of things and corrected some errors.

[mikeraz]

consider

    system("fortune"); 


wait, not those kinds of quotes

Does


    perl -e 'print "hello \"quoted name\"\n";'

do something like you want?

Generally though if you use " and then want to print a " you need to escape it by preceding it with a \ see example above. Generalize to any type of quote character.

[haoess]

% perl -E $'say q{"\'}'
"'

% echo $SHELL 
/bin/zsh

-- Frank