CODEWITHSUNDEEP
bashshell
Dane Jordan
Dane Jordan

Reputation: 1139

Capture command's output without translating "\n" to literal newline

cat file.json gives me what I want to capture inside of $JSON:

{ 
  key: "value\nwith\nnewline\nchars"
}

I can't do JSON=$(cat file.json) though because then the newline characters are translated and I get after echo $JSON or echo -e $JSON.

{
 key: "value
with
newline
chars"
}.

How can I preserve the newline characters inside of $JSON?

Upvotes: 1

Views: 318

Answers (1)

Charles Duffy
Charles Duffy

Reputation: 295520

Capture using command substitution doesn't perform the translation you're worried about here, but using echo (or misusing printf by substituting into the format string rather than a separate parameter) will.

To emit a variable with backslash sequences intact, use:

printf '%s\n' "$JSON"

This avoids behavior that echo can have (either explicitly with bash's noncompliant extension for echo -e, or implicitly when the xpg_echo flag is enabled in bash, or as default out-of-the-box behavior with other, POSIX+XSI-compatible /bin/sh implementations) wherein escape sequences are replaced by echo, even if the variable passed as an argument had a multi-character backslash sequence.

Upvotes: 3

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