Export FZF_CURRENT_ITEM to child processes (#4803)

Close #4802

CHANGELOG.md

@@ -4,6 +4,7 @@ CHANGELOG
 0.73.0
 ------
 - Timer-driven `every(N)` event for `--bind`, where `N` is seconds (fractional, floored to `0.01`). Ticks that overlap an in-flight action are coalesced, so a slow `reload` cannot accumulate a backlog.
+- New `FZF_CURRENT_ITEM` environment variable exported to child processes, holding the text of the current item. Useful on shells where quoting `{}` is awkward (e.g. PowerShell on Windows). Unset when the list is empty (#4802).
 - New `FZF_IDLE_TIME` (whole seconds) and `FZF_IDLE_TIME_MS` (milliseconds) environment variables exported to child processes, holding the elapsed time since the last user activity. Pair with `every(N)` to build idle-based behavior such as auto-accept or auto-quit (#1211).
       ```sh
       # Live process list; --track --id-nth 2 keeps the cursor on the same PID across reloads

man/man1/fzf.1

@@ -1475,6 +1475,8 @@ fzf exports the following environment variables to its child processes.
 .br
 .BR FZF_POS "             Vertical position of the cursor in the list starting from 1"
 .br
+.BR FZF_CURRENT_ITEM "    Text of the current item (unset if the list is empty)"
+.br
 .BR FZF_WRAP "            The line wrapping mode (char, word) when enabled"
 .br
 .BR FZF_QUERY "           Current query string"

src/terminal.go

@@ -1438,6 +1438,9 @@ func (t *Terminal) environImpl(forPreview bool) []string {
 	env = append(env, fmt.Sprintf("FZF_LINES=%d", t.areaLines))
 	env = append(env, fmt.Sprintf("FZF_COLUMNS=%d", t.areaColumns))
 	env = append(env, fmt.Sprintf("FZF_POS=%d", min(t.merger.Length(), t.cy+1)))
+	if item := t.currentItem(); item != nil {
+		env = append(env, "FZF_CURRENT_ITEM="+item.AsString(t.ansi))
+	}
 	env = append(env, fmt.Sprintf("FZF_CLICK_HEADER_LINE=%d", t.clickHeaderLine))
 	env = append(env, fmt.Sprintf("FZF_CLICK_HEADER_COLUMN=%d", t.clickHeaderColumn))
 	env = append(env, fmt.Sprintf("FZF_CLICK_FOOTER_LINE=%d", t.clickFooterLine))

test/test_core.rb

@@ -2286,6 +2286,7 @@ class TestCore < TestInteractive
       FZF_ACTION: 'start',
       FZF_KEY: '',
       FZF_POS: '1',
+      FZF_CURRENT_ITEM: '1',
       FZF_QUERY: '',
       FZF_POINTER: '>',
       FZF_PROMPT: '> ',
@@ -2301,12 +2302,12 @@ class TestCore < TestInteractive
     end
     tmux.send_keys :Tab, :Tab
     tmux.until do
-      expected.merge!(FZF_ACTION: 'toggle-down', FZF_KEY: 'tab', FZF_POS: '3', FZF_SELECT_COUNT: '2')
+      expected.merge!(FZF_ACTION: 'toggle-down', FZF_KEY: 'tab', FZF_POS: '3', FZF_CURRENT_ITEM: '3', FZF_SELECT_COUNT: '2')
       assert_equal expected, env_vars.slice(*expected.keys)
     end
     tmux.send_keys '99'
     tmux.until do
-      expected.merge!(FZF_ACTION: 'char', FZF_KEY: '9', FZF_QUERY: '99', FZF_MATCH_COUNT: '1', FZF_POS: '1')
+      expected.merge!(FZF_ACTION: 'char', FZF_KEY: '9', FZF_QUERY: '99', FZF_MATCH_COUNT: '1', FZF_POS: '1', FZF_CURRENT_ITEM: '99')
       assert_equal expected, env_vars.slice(*expected.keys)
     end
     tmux.send_keys :Space