1

In bash I can do:

foo() { echo bar; }
export -f foo
perl -e 'system "bash -c foo"'

I can also access the function definition:

perl -e 'print "foo".$ENV{"BASH_FUNC_foo%%"}'

How do I do the same in fish?

Edit:

With this I can get the function definition:

functions -n | perl -pe 's/,/\n/g' | while read d; functions $d; end

If I can put that in an enviroment variable accessible from Perl, I ought to be able to execute that before executing the command. So similar to:

setenv funcdefs (functions -n | perl -pe 's/,/\n/g' | while read d; functions $d; end)
perl -e 'system($ENV{"funcdefs"},"foo")'

But it seems setting funcdefs ignores the newlines: $ENV{"funcdefs"} is one horribly long line.

The odd part is that it seems fish does support environment variables containing newlines:

setenv newline 'foo
bar'
echo "$newline"

Can I encourage fish to put the output from the command into a variable, but keeping the newlines?

3
  • Variable contains newline worked fine for me in fish 2.1.0. fish disable word splitting by default.
    – cuonglm
    May 20, 2015 at 11:05
  • @cuonglm I tested with 2.1.1. This still does not work: setenv quux (echo foo;echo bar); echo "$quux". It works beautifully in Bash: quux=$(echo foo;echo bar); echo "$quux"
    – Ole Tange
    May 20, 2015 at 11:48
  • I'm not sure about that. I tried enter newline literally, set var 'foo\nbar'
    – cuonglm
    May 20, 2015 at 12:56

2 Answers 2

2

In fish, you can use funcsave to save function definition across fish session:

$ function qwerty
    echo qwerty
end
$ funcsave qwerty
$ fish -c qwerty
qwerty
$ perl -e 'system "fish -c qwerty"'
qwerty
5
  • Assume it is a function that I will never use again, can I avoid saving it?
    – Ole Tange
    May 20, 2015 at 8:59
  • @OleTange: AFAIK, you can't. You can use functions -e funcname to erase the function after using it.
    – cuonglm
    May 20, 2015 at 9:03
  • Would that not violate the first design principle for fish? fishshell.com/docs/current/design.html
    – Ole Tange
    May 20, 2015 at 10:59
  • @OleTange: I think no. funcsave can do job that export -f can do and it more powerful than that since when it can work across all fish session. It can be considered the same as what you do in .bashrc
    – cuonglm
    May 20, 2015 at 11:12
  • I respectfully disagree that forcing a function to be globally visible is more powerful than being able to keep it locally visible: I often create a throw-away function called doit. If I create a function in two different windows I do not want one definition to overwrite the other.
    – Ole Tange
    May 20, 2015 at 13:51
0

Ugly as hell, but works:

function foo
  echo bar;
end

setenv funcdefs (functions -n | perl -pe 's/,/\n/g' | while read d; functions $d; end|perl -pe 's/\n/\001/')
perl -e '$ENV{"funcdefs"}=~s/\001/\n/g;system ("fish", "-c", $ENV{funcdefs}."foo")'

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