CODEWITHSUNDEEP
bashshellscriptingprintf
Nacho
Nacho

Reputation: 65

printf - repeating arguments by format

I've an array of strings (variable size...) like this:

arr=( "one str" "another str" "example" "last-string" )

I need the following output:

one str:one str another str:another str example:example last-string:last-string

The problem is that when i do something like:

$(printf " %s:%s" "${arr[@]}")

It iterates over the array, moving to next position of the string (without repeating!), and the result is like:

one str:another str  example:last-string

How can I achive this with printf? without any loops!

I'm using bash 3.1.0(1) in Cygwin if that helps!

Upvotes: 2

Views: 2514

Answers (2)

Candide Guevara Marino
Candide Guevara Marino

Reputation: 2352

A bit hacky but you can try this:

arr=( "one str" "another str" "example" "last-string" )
intermediate_result=`printf " %s:%%s" "${arr[@]}"`
printf "$intermediate_result" "${arr[@]}"

Upvotes: 0

Adam Rosenfield
Adam Rosenfield

Reputation: 400512

You can't do this with bash's built-in printf function. You'll either need to use a loop or an external program, e.g. Python:

# With a loop:
for x in "${arr[@]}"; do
  printf " %s:%s" "$x" "$x"
done

# With Python
python -c 'import sys; print "".join(" %s:%s" % (arg, arg) for arg in sys.argv[1:])' "${arr[@]}"

Upvotes: 1

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