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From: Ray Andrews <rayandrews@eastlink.ca>
To: Zsh Users <zsh-users@zsh.org>
Subject: array with newlines preserved as literal text
Date: Tue, 2 Feb 2021 11:16:27 -0800	[thread overview]
Message-ID: <52dba8e4-2538-7c96-ecd5-66e017ab2b8e@eastlink.ca> (raw)

I create some nasty output involving a grep search, save to to a 
variable, send it to a function which ends up calling 'eval' which 
receives the input and executes it like this:

     @ eval "$@"
     echo "\nYou (hard return)
     will\\nregret'\x0a'\nthe day you '\n' were born."

... I can save the output to a file perfectly:
     $ eval "$@" >! junk

     $ cat junk
     echo "\nYou (hard return)
     will\\nregret'\x0a'\nthe day you '\n' were born."   # Perfectly 
identical.

... and I can recapture that text from the file to a variable like this:

     $ typeset -a array1=( "${(q+)$(<junk)}" )

     $ print -l $array1
     $'    echo "\nYou (hard return)
     will\\nregret'\x0a'\nthe day you '\n' were born."'

... pretty good.  And there's probably a way of stripping off the outer: 
$'...'.
But if I try to capture the output to a variable directly:

     $ array2=$(eval "$@")

... the results are spectacularly  bad no matter how I dress it up with 
' ${(f)....}' or quotes  any other invocation I can think of. But 
surely  there's a way.   I understand newlines are hard to ignore.  
Various ideas would treat the text: ' \n ' as text alright but also 
ignore the 'real' newline that is invisible in an editor but must of 
course be there in the real string so everything would end up on one 
line.  Instead of using '(q+)' I tried '(F)' and stripped out the 
newlines like this: 'array2=${array2//'\n'/-NL-}' and it sorta works but 
it's vulgar.  The ' \x0a' is forgivable. Note that the input of all this 
is grep searches in code, so the lines found are bound to contain all 
sorts of rotten stuff, but I want literal output.
How do I pull this off?  There will be a way.



             reply	other threads:[~2021-02-02 19:17 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-02 19:16 Ray Andrews [this message]
2021-02-02 19:26 ` Roman Perepelitsa
2021-02-03  1:10   ` Ray Andrews
2021-02-02 20:25 ` Bart Schaefer
2021-02-02 23:31   ` Ray Andrews
2021-02-03  2:21     ` Bart Schaefer
2021-02-03 19:29       ` Ray Andrews
2021-02-03 21:19         ` Bart Schaefer
2021-02-04  2:07           ` Ray Andrews
2021-02-05  2:57             ` Bart Schaefer
2021-02-04 21:55           ` Ray Andrews
2021-02-05  3:22             ` Bart Schaefer
2021-02-05  4:17               ` Ray Andrews
2021-02-05  4:24                 ` Bart Schaefer

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