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I am in a situation that can not find a solution for my case.

I need to run a long command in bash, say:

node -p "const db = {1:1, 2:2};Object.keys(db).sort((a, b)=> a-b).map(Number).filter((n) => {return !isNaN(n)})"

Due to this command is relative long, I tried to use \ to wrap my command. Like this:

node -p "const db = {1:1, 2:2};Object.keys(db)\
.sort((a, b)=> a-b).map(Number).filter((n) => {return !isNaN(n)})"

But it complained that

bash: !isNaN: event not found

which I find similar to this question

So I tried to replace " with ':

node -p 'const db = {1:1, 2:2};Object.keys(db)\
.sort((a, b)=> a-b).map(Number).filter((n) => {return !isNaN(n)})'

But this time, \ is considered part of the command which is actually meaningless because I just want to wrap my command.

How can I solve this delemma?

Kusalananda
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krave
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  • You can temporarily turn off history expansion with `set +o histexpand` or `set +H`. – Deathgrip Feb 13 '22 at 20:59
  • Does that code need to be passed as one line? I mean, if you use single quotes and remove the backslash, the string `node` gets would just have the newline right where it is, and you could just wrap the code in any way that works for the actual parser. – ilkkachu Feb 13 '22 at 21:10
  • @ikk The code can be passed as several lines but which means I need to enter node REPL which is another environment instead bash. – krave Feb 14 '22 at 07:13

1 Answers1

2

Use a combination of single and double quotes, or just put the \! outside the quotes. In general using single quotes causes less surprises.

node -p "const db = {1:1, 2:2};Object.keys(db)\
.sort((a, b)=> a-b).map(Number).filter((n) => {return "\!"isNaN(n)})"

node -p "const db = {1:1, 2:2};Object.keys(db)\
.sort((a, b)=> a-b).map(Number).filter((n) => {return "'!'"isNaN(n)})"

node -p 'const db = {1:1, 2:2};Object.keys(db)'\
'.sort((a, b)=> a-b).map(Number).filter((n) => {return !isNaN(n)})'
icarus
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