Beefy Boxes and Bandwidth Generously Provided by pair Networks
Come for the quick hacks, stay for the epiphanies.
 
PerlMonks  

Re^4: Having to manually escape quote character in args to "system"?

by vr (Curate)
on Sep 20, 2017 at 11:53 UTC ( [id://1199727]=note: print w/replies, xml ) Need Help??


in reply to Re^3: Having to manually escape quote character in args to "system"?
in thread Having to manually escape quote character in args to "system"?

Thank you for reporting a bug for me, in the first place. No, fix is not good (I notified the author). Similar test fails:

>perl -MShellQuote::Any::Tiny=shell_quote -E "system $^X, '-E', 'say f +or @ARGV', 1, shell_quote(qq(\x5c\x5c \x5c)), 2" 1 \\\ \ 2

According to comment in source, [we now] "escape backslash that is followed by a backslash, or the last backslash". That's not what rules 4-7 in MS guidelines say, if we 'reverse' them. 'Reverse', because they say how to parse a command line, and, of course, Perl does it OK for all test cases provided on that page:

perl -E "system $^X, '-E', 'say for @ARGV', qq(\x22abc\x22 d e)" perl -E "system $^X, '-E', 'say for @ARGV', qq(a\x5c\x5c\x5cb d\x22e f +\x22g h)" perl -E "system $^X, '-E', 'say for @ARGV', qq(a\x5c\x5c\x5c\x22b c d) +" perl -E "system $^X, '-E', 'say for @ARGV', qq(a\x5c\x5c\x5c\x5c\x22b +c\x22 d e)"

While we need the opposite: to escape arguments, so that when Perl #1 simply glues them together, another program (e.g. Perl #2) breaks the CL to the same arguments. Line 24

$arg =~ s/(\\(?!.*\\)|\\(?=\\)|")/\\$1/g;

could be replaced with

$arg =~ s/\\(?=\\*(?:"|$))/\\\\/g; $arg =~ s/"/\\"/g;

Then round-trip tests pass OK (though they are trivial, of course):

perl -MShellQuote::Any::Tiny=shell_quote -E "system $^X, '-E', 'say fo +r @ARGV', map {shell_quote $_} qw(abc d e)" perl -MShellQuote::Any::Tiny=shell_quote -E "system $^X, '-E', 'say fo +r @ARGV', map {shell_quote $_} qq(a\x5c\x5c\x5cb), 'de fg', 'h'" perl -MShellQuote::Any::Tiny=shell_quote -E "system $^X, '-E', 'say fo +r @ARGV', map {shell_quote $_} qq(a\x5c\x22b), 'c', 'd'" perl -MShellQuote::Any::Tiny=shell_quote -E "system $^X, '-E', 'say fo +r @ARGV', map {shell_quote $_} qq(a\x5c\x5cb c), 'd', 'e'"

Edit. P.S. Issue fixed (on the same day) in 0.007 version. I'm out of issues.

:-)

Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Node Status?
node history
Node Type: note [id://1199727]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others sharing their wisdom with the Monastery: (5)
As of 2024-03-29 11:02 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found