如何在双引号内使用双引号

Question

Consider the following:

var child = require('child_process');
var res = child.execSync("df -l | awk '{t += $2} END {printf "%d G\n", t / 2^20 + 0.5}'");

I'm getting a syntax error (the " in printf are at fault here).

I tried to escape using \\" , to no avail.

Using: "df -l | awk '{t += $2} END {printf \\"%d G\\n\\", t / 2^20 + 0.5}'" .

I get:

awk: cmd. line:1: {t += $2} END {printf "%d G
awk: cmd. line:1:                       ^ unterminated string

What is the syntactically correct way to proceed here?

Answer 1

var res = child.execSync("df -l | awk \\'{t += $2} END {printf \\"%d G\\\\n\\", t / 2^20 + 0.5}\\'");

works, tested.

The problem was with \\n . It should be \\\\n . You can debug any shell task like this: console.log(SHELL_COMMAND) and then mannually run output string.

For example, this:

var child = require('child_process');
var cmd = "df -l | awk '{t += $2} END {printf \"%d G\n\", t / 2^20 + 0.5}'";
console.log(cmd)
var res = child.execSync(cmd);

will output in console and try to run this:

df -l | awk '{t += $2} END {printf "%d G
", t / 2^20 + 0.5}'

which makes no sense.