Add function os.PasteFromClipboard

And a user config to override it with a custom command.

docs/Config.md

@@ -415,9 +415,13 @@ os:
   openLinkCommand: ""
 
   # CopyToClipboardCmd is the command for copying to clipboard.
-  # See https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#custom-command-for-copying-to-clipboard
+  # See https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#custom-command-for-copying-to-and-pasting-from-clipboard
   copyToClipboardCmd: ""
 
+  # ReadFromClipboardCmd is the command for reading the clipboard.
+  # See https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#custom-command-for-copying-to-and-pasting-from-clipboard
+  readFromClipboardCmd: ""
+
 # If true, don't display introductory popups upon opening Lazygit.
 disableStartupPopups: false
 
@@ -620,7 +624,7 @@ os:
   open: 'open {{filename}}'
 ```
 
-## Custom Command for Copying to Clipboard
+## Custom Command for Copying to and Pasting from Clipboard
 ```yaml
 os:
   copyToClipboardCmd: ''
@@ -633,6 +637,12 @@ os:
   copyToClipboardCmd: printf "\033]52;c;$(printf {{text}} | base64)\a" > /dev/tty
 ```
 
+A custom command for reading from the clipboard can be set using
+```yaml
+os:
+  readFromClipboardCmd: ''
+```
+It is used, for example, when pasting a commit message into the commit message panel. The command is supposed to output the clipboard content to stdout.
 
 ## Configuring File Editing
 

pkg/commands/oscommands/os.go

@@ -302,6 +302,23 @@ func (c *OSCommand) CopyToClipboard(str string) error {
 	return clipboard.WriteAll(str)
 }
 
+func (c *OSCommand) PasteFromClipboard() (string, error) {
+	var s string
+	var err error
+	if c.UserConfig.OS.CopyToClipboardCmd != "" {
+		cmdStr := c.UserConfig.OS.ReadFromClipboardCmd
+		s, err = c.Cmd.NewShell(cmdStr).RunWithOutput()
+	} else {
+		s, err = clipboard.ReadAll()
+	}
+
+	if err != nil {
+		return "", err
+	}
+
+	return strings.ReplaceAll(s, "\r\n", "\n"), nil
+}
+
 func (c *OSCommand) RemoveFile(path string) error {
 	msg := utils.ResolvePlaceholderString(
 		c.Tr.Log.RemoveFile,

pkg/config/user_config.go

@@ -565,8 +565,12 @@ type OSConfig struct {
 	OpenLinkCommand string `yaml:"openLinkCommand,omitempty"`
 
 	// CopyToClipboardCmd is the command for copying to clipboard.
-	// See https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#custom-command-for-copying-to-clipboard
+	// See https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#custom-command-for-copying-to-and-pasting-from-clipboard
 	CopyToClipboardCmd string `yaml:"copyToClipboardCmd,omitempty"`
+
+	// ReadFromClipboardCmd is the command for reading the clipboard.
+	// See https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#custom-command-for-copying-to-and-pasting-from-clipboard
+	ReadFromClipboardCmd string `yaml:"readFromClipboardCmd,omitempty"`
 }
 
 type CustomCommandAfterHook struct {

schema/config.json

@@ -796,7 +796,11 @@
         },
         "copyToClipboardCmd": {
           "type": "string",
-          "description": "CopyToClipboardCmd is the command for copying to clipboard.\nSee https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#custom-command-for-copying-to-clipboard"
+          "description": "CopyToClipboardCmd is the command for copying to clipboard.\nSee https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#custom-command-for-copying-to-and-pasting-from-clipboard"
+        },
+        "readFromClipboardCmd": {
+          "type": "string",
+          "description": "ReadFromClipboardCmd is the command for reading the clipboard.\nSee https://github.com/jesseduffield/lazygit/blob/master/docs/Config.md#custom-command-for-copying-to-and-pasting-from-clipboard"
         }
       },
       "additionalProperties": false,