"Backticks considered deprecated" question

genss · 05-19-2015, 01:00 PM

i use backtics as it's much easier to write
for nested id use $()

last i checked ` is still in POSIX

millgates · 05-19-2015, 01:26 PM

Usage of the $() is generally recommended in bash, but I wouldn't go as far as calling backticks deprecated.
Regarding compatibility issues, $() is a part of POSIX, so I wouldn't wory about anything but very old systems.
Personally, I prefer $() and usually recommend it over the backticks. Now both can do the same, so if anyone prefers backticks, I'm fine with that.
In addition to the advantages already mentioned, Here's a few other things I like about the "new" syntax:

1/ Consistent syntax with the other "variable-like" expressions:

Code:

$foo     # a variable
${foo,,} # a variable obtained from string manipulation
$((foo)) # a variable obtained from an arithmetic expression
$(foo)   # a variable obtained from a command
$(<foo)  # a variable obtained from a file

2/ Most of the times you use command substitution, you should put it within double quotes, and (in my opinion)

Code:

"$(foo "a b")"

is nicer and more readable than

Code:

"`foo "a b"'"

3/ most text editors will highlight matching pairs of parentheses, but not backticks.

Keith Hedger · 05-19-2015, 07:18 PM

Back when I was using OSX and starting to use the shell, I found that when typing some examples they didn't work but copying and pasting did, it took me ages to realize that there is a difference between ' and `. It can be confusing to a newb so I would always use $() especially when posting code examples on this forum, $() has been in POSIX for ages now so I don't see the point of using bacticks when $() is much easier to read, depending on your font ' and ` can be almost indistinguishable, especially for those ( like me ) that have bad eysight.

MensaWater · 05-21-2015, 10:12 AM

Quote:

Originally Posted by rnturn

I think Coherent had a Korn variant (pdksh?) but I never used it.

In RHEL4 they had pdksh rather than ksh available and it worked well enough. Starting with RHEL5 they have true ksh.