Wayland: Global hook to yank operations with wl-copy waits command to finish forever

[3ynm]

Steps

Copy the following to your kakrc:

# Use system's clipboard
hook global NormalKey y|d|c %{ nop %sh{
  printf %s "$kak_main_reg_dquote" | wl-copy
}}

reload the kakoune config and yank something

Outcome

kakoune says waiting for shell command to finish until you press Ctrl+C

Expected

Should not expect command to finish, because it contains the copied contents.

Related to #2325

[sam-willis]

I think this is related to wl-copy actually continuing to run in the background. On yanking kakoune freezes, and the buffer is copied to the system clipboard, but if you C-c (ending the process and unfeezing kakoune) the system clipboard clears.

[3ynm]

Yes, it is because of that. As I said my expected result is "Should not expect command to finish, because it contains the copied contents." I don't know how to do that, or if even it is feasible.

[laelath]

I don't have a wayland compositor installed to test, but I think this would work?

# Use system's clipboard
hook global NormalKey y|d|c %{ nop %sh{
  printf %s "$kak_main_reg_dquote" | wl-copy > /dev/null 2>&1 &
}}

[3ynm]

Yes it does :D!! Posted it in the wiki, thanks!

Would be great if you explain why this works... I've tried running the process in background, but not with redirecting outputs, I don't grok it really.

[Screwtapello]

The %sh{} expansion runs a shell-script and collects its output, then waits for the script to exit. To prevent Kakoune from waiting for a long-running process, you need to:

• redirect stdout with > /dev/null so that the long-running process does not inherit the shell's stdout, and therefore the stdout Kakoune reads will be closed immediately when the shell exits
• redirect stderr with 2> /dev/null (or if stdout is already redirected, 2>&1) for the same reason
• run the process in the background with & so the shell exits 0 immediately instead of waiting for the long-running process to exit