Fish: Iterate over a string

Question

How would you iterate over a string in the fish shell?

Unfortunately iterating over a string isn't as straight forward as iterating over a list:

↪ for c in a b c
      echo $c
  end
a
b
c

↪ for c in abc
      echo $c
  end
abc

Answer 1

The for loop in fish operates on a list.

for VARNAME in [VALUES...]; COMMANDS...; end

The builtin string command (since v2.3.0) can be used to split a string into a list of characters.

↪ string split '' abc
a
b
c

The output is a list, so array operations will work.

↪ for c in (string split '' abc)
      echo $c
  end
a
b
c

A more complex example iterating over the string with an index.

↪ set --local chars (string split '' abc)
  for i in (seq (count $chars))
      echo $i: $chars[$i]
  end
1: a
2: b
3: c