Reload command does not use the SHELL

[avdv]

• I have read through the manual page (man fzf)
• I have the latest version of fzf (0.42.0 (d471067))
• I have searched through the existing issues

Info

• OS
  • Linux
  • Mac OS X
  • Windows
  • Etc.
• Shell
  • bash
  • zsh
  • fish

Problem / Steps to reproduce

From reading the man page and looking at #1750 I got the idea that one could use FZF_DEFAULT_COMMAND in the reload action, but that does not work like advertised:

export FZF_DEFAULT_COMMAND='echo "test"' SHELL=bash

fzf  --bind 'ctrl-r:reload:$FZF_DEFAULT_COMMAND' --preview 'echo $FZF_DEFAULT_COMMAND'

When run, this displays test in the result list. When hitting ctrl-r it displays "test" (including the quotes).

So in order to use the FZF_DEFAULT_COMMAND in reload you would have to pass it to the SHELL explicitly:

export FZF_DEFAULT_COMMAND='echo "test"' SHELL=bash

fzf  --bind 'ctrl-r:reload:$SHELL -c "$FZF_DEFAULT_COMMAND"' --preview 'echo $FZF_DEFAULT_COMMAND'

[LangLangBart]

When run, this displays test in the result list. When hitting ctrl-r it displays "test" (including the quotes).

• try with eval
  • ref: bash manual - eval
  • ref: "[Command failed: $FZF_DEFAULT_COMMAND]" when reloading and the variable contains spaces #2887 (comment) (29/Jul/22)

fzf  --bind 'ctrl-r:reload:eval $FZF_DEFAULT_COMMAND'

---

So in order to use the FZF_DEFAULT_COMMAND in reload you would have to pass it to the SHELL explicitly:

export FZF_DEFAULT_COMMAND='echo "test"' SHELL=bash

fzf  --bind 'ctrl-r:reload:$SHELL -c "$FZF_DEFAULT_COMMAND"' --preview 'echo $FZF_DEFAULT_COMMAND'

• seems to be superfluous, because fzf already does that by using $SHELL -c COMMAND

man fzf
# FZF_DEFAULT_COMMAND
#   Default command to use when input is tty. On *nix  systems,  fzf runs the command
#   with $SHELL -c if SHELL is set, otherwise with sh -c, so in this case make sure
#   that the command is POSIX-compliant.

[junegunn]

fzf does use $SHELL.

When run, this displays test in the result list. When hitting ctrl-r it displays "test" (including the quotes).

You'll get the same result if you do the same on bash

bash

$ export FZF_DEFAULT_COMMAND='echo "test"'
$ $FZF_DEFAULT_COMMAND
"test"

So, use eval as suggested by @LangLangBart

$ eval "$FZF_DEFAULT_COMMAND"
test

[avdv]

Thank you. Yes, you are right. I quickly run fzf with strace and didn't spot the bash -c call somehow (probably because I was looking for the wrong thing).

The confusion (and different behavior) just comes from the fact that when setting FZF_DEFAULT_COMMAND fzf already gets the value of the variable and then calls $SHELL -c <value> whereas inside the reload command it literally calls $SHELL -c $FZF_DEFAULT_COMMAND.

The example from #1750 makes it look like those two things should be identical:

FZF_DEFAULT_COMMAND='find . -type f' fzf \
  --bind 'ctrl-d:reload(find . -type d),ctrl-f:reload($FZF_DEFAULT_COMMAND)'

It would help to call this out more explicitly.

That one needs to evaluate the variable manually, either by using bash -c $FZF_DEFAULT_COMMAND or eval $FZF_DEFAULT_COMMAND or just letting the shell expand the variable in the --bind call directly.