Zsh - split string by spaces when using dot operator

Question

Here is my script:

#/bin/bash
list="a b c"
for i in $list; do
  echo $i
done

This works:

➜  ~  ./lol.sh 
a
b
c

This doesn't:

➜  ~  . ./lol.sh 
a b c

Why split does not work with dot command and how can I fix it?

I cannot duplicate your problem using bash 3 or bash 4. What version are you running? — jim mcnamara
– jim mcnamara, Commented Aug 24, 2015 at 15:30
...so, the dot operator isn't actually a factor in this issue, except inasmuch as it changes which shell you're actually running the code in. Straighten out which shell in your environment is which, and you'll have removed it as a factor. — Charles Duffy
– Charles Duffy, Commented Aug 24, 2015 at 15:48
I too was having the same issue - in zsh.... Using @CharlesDuffy info ... I modded my script. ```bash — Tim Seed
– Tim Seed, Commented Jan 16, 2021 at 1:16

karolba · Accepted Answer · 2020-05-03 16:56:21Z

12

Lists should never be represented as strings. Use array syntax.

list=( a b c )
for i in "${list[@]}"; do
  echo "$i"
done

There are several reasons this is preferable.

In ZSH:

ZSH breaks POSIX by not performing string-splitting at all on unquoted expansions unless they explicitly request it. You can make this request by either running setopt sh_word_split, or using the parameter expansions ${=list} or ${(ps: :)list}

In other Bourne-derived shells:

String-splitting is dependent on the value of IFS, which cannot be guaranteed to be at defaults, especially when sourced from a separate script (which may have changed it locally).
Unquoted expansion also performs globbing, which can have different results depending on which files are in the current working directory (for instance, if your list contains hello[world], this will behave in an unexpected manner if your current directory contains files named hellow, helloo, or otherwise matching the glob).
Avoiding the globbing step is not only more correct, but also more efficient.

edited May 3, 2020 at 16:56

karolba

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answered Aug 24, 2015 at 15:34

Charles Duffy

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3 Comments

lstipakov Over a year ago

Thanks, works in bash but zsh says: ./lol.sh: 2: ./lol.sh: Syntax error: "(" unexpected

Charles Duffy Over a year ago

Are you very, very sure you were testing with ZSH, not /bin/sh? "(" unexpected is exactly what you'd get from dash, ash or similar POSIX shells from that code.

Charles Duffy Over a year ago

Let us continue this discussion in chat.

Tim Seed · Accepted Answer · 2021-01-16 01:18:50Z

0

Whilst I note the comment regarding lists by Charles Duffy, this was my solution/test.

#!/bin/zsh
function three()
{
        first=$1
        second=$2
        third=$3
        echo "1: $first 2: $second 3:$third"
}

setopt sh_word_split
set "1 A 2" "2 B 3" "3 C 4" "4 D 5"
for i;do
        three $i;

 done

This will output

1: 1 2: A 3:2
1: 2 2: B 3:3
1: 3 2: C 3:4
1: 4 2: D 3:5

answered Jan 16, 2021 at 1:18

Tim Seed

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