CODEWITHSUNDEEP
bashlistfor-loop
juststuck
juststuck

Reputation: 656

How to create a string list from the loop in bash?

I have a following loop:

for chr in {1..3};
do
futureList="${variable1} ${variable2}"
done

I would like to modify it so that futureList appends new set of variables in each consecutive cycle. Expected outcome should look something like this:

echo $futureList

string1 string2, string3 string4, string5 string6 etc

Upvotes: 2

Views: 3622

Answers (2)

Jetchisel
Jetchisel

Reputation: 7791

Here is how I would do it.

n=1
for chr in {1..3}; do
  array1+=("string$n") array2+=("string$((n+3))")
  ((n++))
done

Save the formatted output in the variable futurelist.

printf -v futurelist '%s %s, ' "${array1[@]}" "${array2[@]}"

Check the output

echo "$futurelist"

Output

string1 string2, string3 string4, string5 string6,

I'm pretty sure someone will come up with more ways to do better.

Upvotes: 1

anubhava
anubhava

Reputation: 785128

This is good usecase to use arrays:

var1='string1'
var2='string2'

futureList=() # declare an array

for i in {1..5}; do
   futureList+=("$var1 $var2") # inside loop append value to array
done

# check array content
# decclare -p futureList
# or use printf
printf '%s\n' "${futureList[@]}"


string1 string2
string1 string2
string1 string2
string1 string2
string1 string2

Upvotes: 2

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