bash-在新行上输出每个数组元素

Question

I am trying to create a TSV file from an array that I build inside a loop. I do get the values on each line to be tab separated, but I am not able to export each element of the array on a new line. This is an example:

OUTPUT=()
#header
OUTPUT+=$(printf "col_1\tcol_2\tcol_3")

param_1="bla"
param_2="tra"
param_3="meh"

for i in 1 .. 3
  do
    OUTPUT+=$(printf "$param_1\t$param_2\t$param_3")
done
#export
printf '%s\n' "${OUTPUT[@]}" > test.tsv

I have also tried to put \\n at the end of each string that I insert in the array, but it did not work. Any idea what I am doing wrong? Thank you

Answer 1

To append to an array you should use this syntax:

array+=(content)

Also there is no need to use printf for appending the static text.

Here is a working script:

OUTPUT=()
#header
OUTPUT+=("col_1\tcol_2\tcol_3")

param_1="bla"
param_2="tra"
param_3="meh"

for i in {1..3}
do
    OUTPUT+=("$param_1\t$param_2\t$param_3")
done
#export
printf '%b\n' "${OUTPUT[@]}" > test.tsv

Note use of %b in printf so that escape sequences are interpreted correctly.

Output:

cat test.tsv

col_1   col_2   col_3
bla     tra     meh
bla     tra     meh
bla     tra     meh