What's the difference between
failed_instance=`aws deploy`
and
failed_instance=$(aws deploy)
I'm talking about ` and $(?
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Both are semantically identical, and both are mandated by the POSIX sh standard, but $() is the newer, modern syntax.
- Backslash handling is the same as usual inside
$(), but backslashes require escaping (lots of escaping if nesting) inside backticks. It nests cleanly. Compare
printf '%s\n' "$(foo "$(bar)")" # new POSIX sh syntaxto its old-style equivalent...
printf '%s\n' "`foo \"\`bar\`\"`" # legacy Bourne syntax
Charles Duffy
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Your answer is excellent, as always; however, it would be better if you marked obvious duplicates as such instead of answering them. Thanks in advance. – tripleee Dec 14 '15 at 19:25
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Didn't remember the other instance until after answering, and when I got there, Keith had beat me to it. – Charles Duffy Dec 14 '15 at 20:45
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I never find any answers that are not on the tag wiki either. I added this one there. – that other guy Dec 15 '15 at 01:04