How to split multiple line output to arguments in bash?-CodePudding

Let the output of a program to be a multiple line text:

$: some_program 
↓
line 1
line 2

Now how to use the output so each line is passed as a single argument?

$: count_arguments $(some_program)
↓
4

won't work because it split by new lines and spaces.

count_arguments "$(some_program)"
↓
1

won't work either.

With an intermediary step could the output be read into an array and then use the array as "${arr[@]}"

But I am looking for a one line solution. Is it possible?

CodePudding user response：

With Bashv4 , mapfile is one solution.

mapfile -t output < <(some_command); your_command "${output[@]}"

echo "${#output[*]}"

Counting the output of some_command, just use wc

some_command | wc -l

CodePudding user response：

You could convert the newlines to NULL characters, and use xargs -0 (the -0 tells it to use NULL as a delimiter, instead of whitespace):

some_program | tr '\n' '\0' | xargs -0 count_arguments

There is one possible caveat, though: if xargs thinks there are too many lines (arguments) or they're too big, it'll split them into reasonable-sized groups and run the utility separately on each group. OTOH if xargs thinks that, it's probably right any any method that didn't split them would just straight-up fail.