Replace text with values from array in Bash

Question

I'm trying to replace words with values from an array with "sed". The problem is that the array has a different length for each file, 0, 1 or 9 values. When replacing, the values should be separated with a comma. For example:

array = (one two three)
sed -e "s | value = " text to replace  "| value = " $ {array (*)}  "| g"
the result should look like this: value = one, two, three
and if array = (one) => value = one

Can someone help me please? thank you in advance!

question from:https://stackoverflow.com/questions/65902779/replace-text-with-values-from-array-in-bash

Answer 1

bash variable assignments must not have spaces around the =

array=(one two three)

To join using a single character, IFS is your friend:

IFS=,

# .....v.......................................v.............v...v
sed -e 's/value = " text to replace "/value = "'"${array[*]}"'"/g'
# ..............................................^^^^^^^^^^^^^

My quoting is very deliberate there. I've marked where the single quotes start and stop, and the array expansion must be enclosed in double quotes.

Overall, you were pretty close. Have to be careful with the whitespace, bash can be very sensitive to it.

---

IFS is the shell's "internal field separator" -- it is used to

• split a string into fields

  line="foo,bar:baz"
  IFS=':,'
  read first second third <<<"$line"
  declare -p first second third
  

• join array elements into a single string

  set -- a b c d
  IFS=':,'
  echo "$*"     # _must_ be quoted