new wsh command to save the scrollback

Author: sawka

cmd/wsh/cmd/wshcmd-termscrollback.go

@@ -0,0 +1,105 @@
+// Copyright 2025, Command Line Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/wavetermdev/waveterm/pkg/waveobj"
+	"github.com/wavetermdev/waveterm/pkg/wshrpc"
+	"github.com/wavetermdev/waveterm/pkg/wshrpc/wshclient"
+)
+
+var termScrollbackCmd = &cobra.Command{
+	Use:   "termscrollback",
+	Short: "Get terminal scrollback from a terminal block",
+	Long: `Get the terminal scrollback from a terminal block.
+
+By default, retrieves all lines. You can specify line ranges or get the 
+output of the last command using the --lastcommand flag.`,
+	RunE:                  termScrollbackRun,
+	PreRunE:               preRunSetupRpcClient,
+	DisableFlagsInUseLine: true,
+}
+
+var (
+	termScrollbackLineStart  int
+	termScrollbackLineEnd    int
+	termScrollbackLastCmd    bool
+	termScrollbackOutputFile string
+)
+
+func init() {
+	rootCmd.AddCommand(termScrollbackCmd)
+
+	termScrollbackCmd.Flags().IntVar(&termScrollbackLineStart, "start", 0, "starting line number (0 = beginning)")
+	termScrollbackCmd.Flags().IntVar(&termScrollbackLineEnd, "end", 0, "ending line number (0 = all lines)")
+	termScrollbackCmd.Flags().BoolVar(&termScrollbackLastCmd, "lastcommand", false, "get output of last command (requires shell integration)")
+	termScrollbackCmd.Flags().StringVarP(&termScrollbackOutputFile, "output", "o", "", "write output to file instead of stdout")
+}
+
+func termScrollbackRun(cmd *cobra.Command, args []string) (rtnErr error) {
+	defer func() {
+		sendActivity("termscrollback", rtnErr == nil)
+	}()
+
+	// Resolve the block argument
+	fullORef, err := resolveBlockArg()
+	if err != nil {
+		return err
+	}
+
+	// Get block metadata to verify it's a terminal block
+	metaData, err := wshclient.GetMetaCommand(RpcClient, wshrpc.CommandGetMetaData{
+		ORef: *fullORef,
+	}, &wshrpc.RpcOpts{Timeout: 2000})
+	if err != nil {
+		return fmt.Errorf("error getting block metadata: %w", err)
+	}
+
+	// Check if the block is a terminal block
+	viewType, ok := metaData[waveobj.MetaKey_View].(string)
+	if !ok || viewType != "term" {
+		return fmt.Errorf("block %s is not a terminal block (view type: %s)", fullORef.OID, viewType)
+	}
+
+	// Make the RPC call to get scrollback
+	scrollbackData := wshrpc.CommandTermGetScrollbackLinesData{
+		LineStart:   termScrollbackLineStart,
+		LineEnd:     termScrollbackLineEnd,
+		LastCommand: termScrollbackLastCmd,
+	}
+
+	result, err := wshclient.TermGetScrollbackLinesCommand(RpcClient, scrollbackData, &wshrpc.RpcOpts{
+		Route:   fullORef.String(),
+		Timeout: 5000,
+	})
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error getting terminal scrollback: %v\n", err)
+		return err
+	}
+
+	// Format the output
+	output := strings.Join(result.Lines, "\n")
+	if len(result.Lines) > 0 {
+		output += "\n" // Add final newline
+	}
+
+	// Write to file or stdout
+	if termScrollbackOutputFile != "" {
+		err = os.WriteFile(termScrollbackOutputFile, []byte(output), 0644)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error writing to file %s: %v\n", termScrollbackOutputFile, err)
+			return err
+		}
+		fmt.Printf("terminal scrollback written to %s (%d lines)\n", termScrollbackOutputFile, len(result.Lines))
+	} else {
+		fmt.Print(output)
+	}
+
+	return nil
+}

docs/docs/wsh-reference.mdx

@@ -792,6 +792,57 @@ wsh setvar -b client MYVAR=value
 
 Variables set with these commands persist across sessions and can be used to store configuration values, secrets, or any other string data that needs to be accessible across blocks or tabs.
 
+---
+
+## termscrollback
+
+Get the terminal scrollback from a terminal block. This is useful for capturing terminal output for processing or archiving.
+
+```sh
+wsh termscrollback [-b blockid] [flags]
+```
+
+By default, retrieves all lines from the current terminal block. You can specify line ranges or get only the output of the last command.
+
+Flags:
+
+- `-b, --block <blockid>` - specify target terminal block (default: current block)
+- `--start <line>` - starting line number (0 = beginning, default: 0)
+- `--end <line>` - ending line number (0 = all lines, default: 0)
+- `--lastcommand` - get output of last command (requires shell integration)
+- `-o, --output <file>` - write output to file instead of stdout
+
+Examples:
+
+```sh
+# Get all scrollback from current terminal
+wsh termscrollback
+
+# Get scrollback from a specific terminal block
+wsh termscrollback -b 2
+
+# Get only the last command's output
+wsh termscrollback --lastcommand
+
+# Get a specific line range (lines 100-200)
+wsh termscrollback --start 100 --end 200
+
+# Save scrollback to a file
+wsh termscrollback -o terminal-log.txt
+
+# Save last command output to a file
+wsh termscrollback --lastcommand -o last-output.txt
+
+# Process last command output with grep
+wsh termscrollback --lastcommand | grep "ERROR"
+```
+
+:::note
+The `--lastcommand` flag requires shell integration to be enabled. This feature allows you to capture just the output from the most recent command, which is particularly useful for scripting and automation.
+:::
+
+---
+
 ## wavepath
 
 The `wavepath` command lets you get the paths to various Wave Terminal directories and files, including configuration, data storage, and logs.