Add support for dumping data to file

Author: Your Name

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "frida-cshell",
-  "version": "1.8.5",
+  "version": "1.8.6",
   "description": "Frida's CShell",
   "scripts": {
     "prepare": "npm run version && npm run build && npm run package && npm run copy",

package.json

@@ -0,0 +1,48 @@
+import { CmdLetBase } from '../../commands/cmdlet.js';
+import { Output } from '../../io/output.js';
+import { Format } from '../../misc/format.js';
+import { Token } from '../../io/token.js';
+import { Var } from '../../vars/var.js';
+import { Mem } from '../../memory/mem.js';
+
+export class DumpFileCmdLet extends CmdLetBase {
+  name = 'df';
+  category = 'data';
+  help = 'dump data to file';
+
+  private static readonly USAGE: string = `Usage: df
+
+df filename address bytes - show data
+  filename the name of the file to dump to
+  adress   the address/symbol to dump from
+  count    the count of fields to dump`;
+
+  public runSync(tokens: Token[]): Var {
+    const vars = this.transform(tokens, [
+      this.parseString,
+      this.parseVar,
+      this.parseVar,
+    ]);
+    if (vars === null) return this.usage();
+    const [filename, address, length] = vars as [string, Var, Var];
+    this.dump(filename, address.toPointer(), length.toU64().toNumber());
+    return new Var(filename);
+  }
+
+  private dump(filename: string, address: NativePointer, length: number) {
+    try {
+      const bytes = Mem.readBytes(address, length);
+      Output.debug(`writing ${length} bytes from ${address} to ${filename}`);
+      File.writeAllBytes(filename, bytes.buffer as ArrayBuffer);
+    } catch (error) {
+      throw new Error(
+        `failed to dump ${Format.toHexString(length)} bytes from ${Format.toHexString(address)} to ${filename}, ${error}`,
+      );
+    }
+  }
+
+  public usage(): Var {
+    Output.writeln(DumpFileCmdLet.USAGE);
+    return Var.ZERO;
+  }
+}

src/cmdlets/data/dumpfile.ts

@@ -86,6 +86,7 @@ import { ErrnoCmdLet } from '../misc/errno.js';
 import { SzCmdLet } from '../files/sz.js';
 import { TlsCmdLet } from '../thread/tls.js';
 import { TmpCmdLet } from '../files/tmp.js';
+import { DumpFileCmdLet } from '../data/dumpfile.js';
 
 export class JsCmdLet extends CmdLetBase {
   name = 'js';
@@ -124,6 +125,7 @@ js path - load commandlet JS script
       CoverageBpCmdLet: CoverageBpCmdLet,
       DivCmdLet: DivCmdLet,
       DumpCmdLet: DumpCmdLet,
+      DumpFileCmdLet: DumpFileCmdLet,
       EchoCmdLet: EchoCmdLet,
       EqCmdLet: EqCmdLet,
       ErrnoCmdLet: ErrnoCmdLet,

src/cmdlets/development/js.ts

@@ -73,6 +73,7 @@ import { ErrnoCmdLet } from '../cmdlets/misc/errno.js';
 import { SzCmdLet } from '../cmdlets/files/sz.js';
 import { TlsCmdLet } from '../cmdlets/thread/tls.js';
 import { TmpCmdLet } from '../cmdlets/files/tmp.js';
+import { DumpFileCmdLet } from '../cmdlets/data/dumpfile.js';
 
 export class CmdLets {
   private static byName: Map<string, CmdLet> = new Map<string, CmdLet>();
@@ -91,6 +92,7 @@ export class CmdLets {
     this.registerCmdletType(CoverageBpCmdLet);
     this.registerCmdletType(DivCmdLet);
     this.registerCmdletType(DumpCmdLet);
+    this.registerCmdletType(DumpFileCmdLet);
     this.registerCmdletType(DumpStringCmdLet);
     this.registerCmdletType(EchoCmdLet);
     this.registerCmdletType(EndianCmdLet);