Strings command (#2505)

* added working strings command; no args

* added n, mapping_name and save-as arguments to strings command

* removed unnecessary whitespaces and imports (checked with ruff)

* simplified command function decorator and improve file handling

* accept multiple page names and improve argument handling

* Fix lint

* Update strings.py

* Fix lint

* Fix lint

* Update strings.py

---------

Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>

pwndbg/commands/__init__.py

@@ -790,6 +790,7 @@ def load_commands() -> None:
     import pwndbg.commands.sigreturn
     import pwndbg.commands.spray
     import pwndbg.commands.start
+    import pwndbg.commands.strings
     import pwndbg.commands.telescope
     import pwndbg.commands.tls
     import pwndbg.commands.valist

pwndbg/commands/strings.py

@@ -0,0 +1,62 @@
+from __future__ import annotations
+
+import argparse
+import re
+from typing import List
+
+import pwndbg
+import pwndbg.aglib.memory
+import pwndbg.commands
+from pwndbg.commands import CommandCategory
+from pwndbg.lib.memory import Page
+
+parser = argparse.ArgumentParser(
+    description="Extracts and displays ASCII strings from readable memory pages of the debugged process."
+)
+
+parser.add_argument("-n", type=int, default=4, help="Minimum length of ASCII strings to include")
+parser.add_argument(
+    "page_names",
+    type=str,
+    nargs="*",
+    default=[],
+    help="Mapping to search [e.g. libc].\nCan be used with multiple mappings [e.g libc heap stack]",
+)
+parser.add_argument(
+    "--save-as",
+    type=str,
+    default=None,
+    help="Sets the filename for the output of this command [e.g. --save-as='out.txt']",
+)
+
+
+@pwndbg.commands.ArgparsedCommand(parser, category=CommandCategory.LINUX)
+@pwndbg.commands.OnlyWhenRunning
+def strings(n: int = 4, page_names: List[str] = [], save_as: str = None):
+    # Extract pages with PROT_READ permission
+    readable_pages: List[Page] = [page for page in pwndbg.aglib.vmmap.get() if page.read]
+
+    for page in readable_pages:
+        if page_names and not any(name in page.objfile for name in page_names):
+            continue  # skip if page does not belong to any of the specified mappings
+
+        count = page.memsz
+        start_address = page.vaddr
+
+        try:
+            data = pwndbg.aglib.memory.read(addr=start_address, count=count)
+        except pwndbg.dbg_mod.Error as e:
+            print(f"Skipping inaccessible page at {start_address:#x}: {e}")
+            continue  # skip if access is denied
+
+        # all strings in the `data`
+        strings: List[bytes] = re.findall(rb"[ -~]{%d,}" % n, data)
+        decoded_strings: List[str] = [s.decode("ascii", errors="ignore") for s in strings]
+
+        if not save_as:
+            for string in decoded_strings:
+                print(string)
+            continue
+
+        with open(save_as, "w") as f:
+            f.writelines(string + "\n" for string in decoded_strings)