[CentOS] Assitance with perl

Orion Poplawski
Mon, 31 Jan 2022 04:00:58 -0000

On 1/30/22 18:12, H wrote:
> I am writing a long bash script under CentOS 7 where perl is used for
manipulating some external files. So far I am using perl one-liners to do so but
ran into a problem when I need to append text to an external file.
>
> Here is a simplified example in the bash script where txt is a bash
variable which I built containing a longish text with multiple newlines:
>
> txt="a b$'\n'cd ef$'\n'g h$'\n'ij kl"
>
> A simplified perl one-liner to append the text in the variable above to
some file in the bash script would be:
>
> perl -pe 'eof && do{print $_'"${txt}"';
exit}' someexternalfile.txt
>
> This works when fine when $txt does /not/ contain any spaces but falls
apart when it does.
>
> I would like to keep the above structure, ie using bash variables to build
text strings and one-liners to do the text manipulation. Hopefully there is a
"simple" solution to do this, I have tried many variations and failed
miserably... Note that I also want to use a similar pattern to do substitutions
in external files, I would thus like to use the same code pattern.

I don't understand why:

echo -e $txt >> someexternalfile.txt

doesn't do what you want, or if perl is absolutely what you need:

perl -e "print \"${txt}\";" >> someexternalfile.txt

I have no idea if you are trying to output literal $'s or 's or not.

--
Orion Poplawski
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