Print array elements on separate lines in Bash?

Question

How do I print the array element of a Bash array on separate lines? This one works, but surely there is a better way:

$ my_array=(one two three)
$ for i in ${my_array[@]}; do echo $i; done
one
two
three

Tried this one but it did not work:

$ IFS=$'\n' echo ${my_array[*]}
one two three

Answer 1

Try doing this :

$ printf '%s\n' "${my_array[@]}"

The difference between $@ and $* :

• Unquoted, the results are unspecified. In Bash, both expand to separate args and then wordsplit and globbed.

• Quoted, "$@" expands each element as a separate argument, while "$*" expands to the args merged into one argument: "$1c$2c..." (where c is the first char of IFS ).

You almost always want "$@" . Same goes for "${arr[@]}" .

Always quote them!

Answer 2

Just quote the argument to echo:

( IFS=$'\n'; echo "${my_array[*]}" )

the sub shell helps restoring the IFS after use

Answer 3

Using for :

for each in "${alpha[@]}"
do
  echo "$each"
done

Using history ; note this will fail if your values contain ! :

history -p "${alpha[@]}"

Using basename ; note this will fail if your values contain / :

basename -a "${alpha[@]}"

Using shuf ; note that results might not come out in order:

shuf -e "${alpha[@]}"

Answer 4

Another useful variant is pipe to tr :

echo "${my_array[@]}" | tr ' ' '\\n'

This looks simple and compact

Answer 5

I tried the answers here in a giant for...if loop, but didn't get any joy - so I did it like this, maybe messy but did the job:

 # EXP_LIST2 is iterated    
 # imagine a for loop
     EXP_LIST="List item"    
     EXP_LIST2="$EXP_LIST2 \n $EXP_LIST"
 done 
 echo -e $EXP_LIST2

although that added a space to the list, which is fine - I wanted it indented a bit. Also presume the "\\n" could be printed in the original $EP_LIST.

Answer 6

You could use a Bash C Style For Loop to do what you want.

my_array=(one two three)

for ((i=0; i < ${#my_array[@]}; i++ )); do echo "${my_array[$i]}"; done
one
two
three

Answer 7

I've discovered that you can use eval to avoid using a subshell. Thus:

IFS=$'\n' eval 'echo "${my_array[*]}"'