Fzf: Can fzf run with pipes as stdin/stdout?

[ShuguangSun]

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

Info

• OS
  
  
  
  • [ ] Linux
  
  
  • [ ] Mac OS X
  
  
  • [x] Windows
  
  
  • [ ] Etc.
  
  
• Shell
  
  
  
  • [ ] bash
  
  
  • [ ] zsh
  
  
  • [ ] fish
  
  
  • [x] Emacs + CMD
  
  

Problem / Steps to reproduce

I run fzf in Windows 10, and it works as expected in the cmd box for the call fzf --filter="tmp" which will give a list of findings.

When I try to use it in Emacs, it fails to capture the output. I consulted in the Emacs help maillist, and it suggested that It looks like fzf uses direct screen I/O? If so, this won't work on Windows when stdout is a pipe, which is what happens when Emacs on Windows runs a subprocess. Whether could we make fzf run with pipes as stdin/stdout?

Best Regards,

[junegunn]

I'm not an Emacs user, so I can't really answer the question, but fzf is designed to work with stdin/stdout pipes.

seq 10 | fzf | cowsay

This is possible because fzf reads from /dev/tty instead of stdin, and prints the finder to stderr instead of stdout. So make sure that stderr of the process is not captured by Emacs. On Vim, system('no-such-command') captures stderr as well, so we use built-in terminal to start fzf instead of using system().