"[Command failed: $FZF_DEFAULT_COMMAND]" when reloading and the variable contains spaces

[matatk]

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

Info

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

I found #1830 and #1408 but this seems to be a different issue.

I'm running on macOS with zsh, and fzf 0.31.0 (brew). I have run the install script and sourced ~/.fzf.zsh.

Summary: when using reload() in conjunction with the $FZF_DEFAULT_COMMAND variable, I get an error if the command contains spaces. However, I can use commands that contain spaces inside reload() if I hard code them. I accept this may be a config issue on my end, though I am not aware of having changed any settings that might cause this to break. I also tried running these examples using /bin/sh and had the same problem.

I've just discovered fzf and it looks awesome so far; thanks!

---

When FZF_DEFAULT_COMMAND contains spaces, I get the "[Command failed: $FZF_DEFAULT_COMMAND]" when I try to reload. The ps example fails with that error message:

FZF_DEFAULT_COMMAND='ps -ef' \
  fzf --bind 'ctrl-r:reload($FZF_DEFAULT_COMMAND)' \
      --header 'Press CTRL-R to reload' --header-lines=1 \
      --height=50% --layout=reverse

But if I take out the -ef part, it works (in the output from ps I can see the time creep up for the fzf command, so it really is re-running the command):

FZF_DEFAULT_COMMAND='ps' \
  fzf --bind 'ctrl-r:reload($FZF_DEFAULT_COMMAND)' \
      --header 'Press CTRL-R to reload' --header-lines=1 \
      --height=50% --layout=reverse

I tried the same thing with ls just to check the problem relates to the space characters in the variable. This causes the "[Command failed: $FZF_DEFAULT_COMMAND]" error on reload:

FZF_DEFAULT_COMMAND='ls -a' \
  fzf --bind 'ctrl-r:reload($FZF_DEFAULT_COMMAND)' \
      --header 'Press CTRL-R to reload' \
      --height=50% --layout=reverse

...but this works:

FZF_DEFAULT_COMMAND='ls' \
  fzf --bind 'ctrl-r:reload($FZF_DEFAULT_COMMAND)' \
      --header 'Press CTRL-R to reload' \
      --height=50% --layout=reverse

In the man page, the invocation example for reload takes the form <key|event>:reload: as opposed to <key|event>:reload() and I'm not entirely clear on why, but trying the colon syntax didn't affect the behaviour. However the docs there referred me to this example, from #1750:

ps -ef | fzf --bind 'ctrl-r:reload(ps -ef)' --header 'Press CTRL-R to reload' \
             --header-lines=1 --layout=reverse

...and this one worked fine! So it must be something to do with variable expansion?

Please let me know if you need any more info.

[junegunn]

I'm a bash user, and I didn't realize that the example only works on bash.

# Works
SHELL=bash FZF_DEFAULT_COMMAND='ps -ef' \
  fzf --bind 'ctrl-r:reload($FZF_DEFAULT_COMMAND)' \
      --header 'Press CTRL-R to reload' --header-lines=1 \
      --height=50% --layout=reverse

# Fails
SHELL=zsh FZF_DEFAULT_COMMAND='ps -ef' \
  fzf --bind 'ctrl-r:reload($FZF_DEFAULT_COMMAND)' \
      --header 'Press CTRL-R to reload' --header-lines=1 \
      --height=50% --layout=reverse

So it boils down to

# On bash
SOME_COMMAND='echo foo'
$SOME_COMMAND
  # foo

vs.

# On zsh
SOME_COMMAND='echo foo'
$SOME_COMMAND
  # zsh: command not found: echo foo

The solution is simple; use eval.

eval $SOME_COMMAND
  # foo

So you can do this:

FZF_DEFAULT_COMMAND='ps -ef' \
  fzf --bind 'ctrl-r:reload(eval "$FZF_DEFAULT_COMMAND")' \
      --header 'Press CTRL-R to reload' --header-lines=1 \
      --height=50% --layout=reverse

I'll consider updating the examples.