shell - Bash: Passing parameters into environments of specific commands -

i know can pass parameters directly environment so:

parameter=value command

however doesn't work in case below, expect it:

func() {      char in b c             echo $char     done }  while ifs= read line     echo "char: $line" done <<< $(func) 

this has output:

char: b c 

once this:

ifs= while read line     echo "char: $line" done <<< $(func) 

it works fine. output is:

char: char: b char: c 

however have reset ifs parameter, circumvent. , i'd know reason behind this.

i use gnu bash, version 4.3.42(1)-release (x86_64-apple-darwin15.0.0)

this fixed in upcoming 4.4 release of bash.

bash-4.4$ func() > { >     char in b c >     >         echo $char >     done > } bash-4.4$ bash-4.4$ while ifs= read line > >     echo "char: $line" > done <<< $(func) char: char: b char: c 

making here strings work (i.e., documented) bit of on-going process.