I know I can solve this problem several ways, but I'm wondering if there is a way to do it using only bash built-ins, and if not, what is the most efficient way to do it.
I have a file with contents like
AAA
B C DDD
FOO BAR
by which I only mean it has several lines and each line may or may not have spaces. I want to run a command like
cmd AAA "B C DDD" "FOO BAR"
If I use cmd $(< file)
I get
cmd AAA B C DDD FOO BAR
and if I use cmd "$(< file)"
I get
cmd "AAA B C DDD FOO BAR"
How do I get each line treated a exactly one parameter?
Best Answer
Portably:
Or using a subshell to make the
IFS
and option changes local:The shell performs field splitting and filename generation on the result of a variable or command substitution that is not in double quotes. So you need to turn off filename generation with
set -f
, and configure field splitting withIFS
to make only newlines separate fields.There's not much to be gained with bash or ksh constructs. You can make
IFS
local to a function, but notset -f
.In bash or ksh93, you can store the fields in an array, if you need to pass them to multiple commands. You need to control expansion at the time you build the array. Then
"${a[@]}"
expands to the elements of the array, one per word.