Shell commands (#547)

* Implement shell interaction commands

* Use slice instead of iterator for shell invocation

* Default to `sh` instead of `$SHELL` for shell commands

* Enforce trailing comma in `commands` macro

* Use `|` register for shell commands

* Move shell config to `editor` and use in command

* Update shell command prompts

* Remove clone of shell config

* Change shell function names to match prompts

* Log stderr contents upon external command error

* Remove `unwrap` calls on potential common errors

`shell` will no longer panic if:
  * The user-configured shell cannot be found
  * The shell command does not output UTF-8

* Remove redundant `pipe` parameter

* Rename `ShellBehavior::None` to `Ignore`

* Display error when shell command is used and `shell = []`

* Document shell commands in `keymap.md`

1 files changed, 7 insertions, 0 deletions

diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 18cb9106..e5ff93ad 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -33,6 +33,8 @@ pub struct Config {
     pub scroll_lines: isize,
     /// Mouse support. Defaults to true.
     pub mouse: bool,
+    /// Shell to use for shell commands. Defaults to ["cmd", "/C"] on Windows and ["sh", "-c"] otherwise.
+    pub shell: Vec<String>,
     /// Line number mode.
     pub line_number: LineNumber,
     /// Middle click paste support. Defaults to true
@@ -55,6 +57,11 @@ impl Default for Config {
             scrolloff: 5,
             scroll_lines: 3,
             mouse: true,
+            shell: if cfg!(windows) {
+                vec!["cmd".to_owned(), "/C".to_owned()]
+            } else {
+                vec!["sh".to_owned(), "-c".to_owned()]
+            },
             line_number: LineNumber::Absolute,
             middle_click_paste: true,
         }