Update README.md

Fix click-to-line behavior in the interactive UI (no-op without a filter,
correct row math when the log hasn't filled the screen) and add a hover
highlight, a persistent pin on the clicked line, and always-visible process
create/death separators so filtered runs stay distinguishable.

CHANGELOG.md

@@ -1,6 +1,32 @@
 Change Log
 ==========
 
+Version 2.4.0 *(2026-07-20)*
+----------------------------
+
+ * Fix: Clicking a line with no filter active was recentering the view instead of doing
+   nothing; it's now a no-op until you actually have something to unfilter.
+ * Fix: Click-to-line row math was off whenever the log hadn't filled the screen yet
+   (e.g. right after startup), so clicks could land on the wrong entry or miss entirely.
+ * New: Hovering over a line highlights it while a filter is active, hinting that it's
+   clickable.
+ * New: The line you click stays highlighted after the filter clears, so you can find
+   it in the full scrollback; the highlight clears once you start another search.
+ * New: Process create/death separators now stay visible even while a filter is active,
+   so you can tell separate app runs apart in filtered results.
+
+Version 2.3.0 *(2026-07-20)*
+----------------------------
+
+ * New: Esc quits the interactive UI. A bare Escape keypress exits; Escape sequences
+   (arrow keys, mouse reports) are still parsed normally.
+ * Fix: Scrolling the interactive UI now works. Up/Down, Page Up/Down, Home/End, and
+   the mouse wheel scroll the retained scrollback; new lines no longer yank you back
+   to the tail while you're scrolled up.
+ * New: Clicking a line in the interactive UI clears the filter, unfilters the log,
+   and scrolls to that line in the full history.
+
+
 Version 2.2.0 *(2026-07-20)*
 ----------------------------
 

CLAUDE.md

@@ -0,0 +1,82 @@
+# pidcat-repl
+
+A fork of [JakeWharton/pidcat](https://github.com/JakeWharton/pidcat) that adds an
+interactive, full-screen filter UI on top of the original package-filtered `adb logcat`
+viewer.
+
+## Layout
+
+Everything lives in a single script, `pidcat.py`. There is no build step, no test suite,
+and no dependencies beyond Python 3 and `adb` on the PATH.
+
+- `stream(emit)` parses `adb logcat` output and hands each formatted block to a callback.
+  Both output modes feed off it.
+- `InteractiveUI` is the fork's addition: alternate-screen rendering, a bottom prompt line,
+  and live filtering of the retained scrollback.
+- `--plain` bypasses `InteractiveUI` and prints blocks as they arrive, which is the
+  upstream behavior. Non-TTY stdin or stdout forces plain mode too.
+
+Run it directly during development: `./pidcat.py com.example.app`.
+
+## Homebrew distribution
+
+This fork is distributed through a personal tap, **not** homebrew-core. Two repos are
+involved:
+
+- `imcarlost/pidcat-repl` (this repo) holds the source and the version tags.
+- `imcarlost/homebrew-pidcat-repl` holds `Formula/pidcat-repl.rb`. Cloned locally at
+  `../homebrew-pidcat-repl`.
+
+The core formula named `pidcat` is upstream's, unrelated to this one. Homebrew derives the
+formula class name from the filename, so `pidcat-repl.rb` must keep the class
+`PidcatRepl`.
+
+### Publishing a new version
+
+The formula pins a tarball URL plus its sha256, so the version bump, the tag, and the
+formula must all move together. Order matters: the sha256 can only be computed after the
+tag is pushed, because it hashes GitHub's generated tarball.
+
+1. Bump `__version__` in `pidcat.py` and promote the `Unreleased` heading in
+   `CHANGELOG.md` to the new version with today's date.
+2. Commit and push to `main`.
+3. Tag and push: `git tag vX.Y.Z && git push origin vX.Y.Z`.
+4. Compute the tarball hash:
+
+   ```sh
+   curl -sL https://github.com/imcarlost/pidcat-repl/archive/refs/tags/vX.Y.Z.tar.gz \
+     | shasum -a 256
+   ```
+
+5. In `../homebrew-pidcat-repl/Formula/pidcat-repl.rb`, update both the `url` version and
+   the `sha256`. Commit and push.
+
+Keep `__version__` in sync with the tag. A mismatch is invisible until someone runs
+`pidcat --version` and sees the old number.
+
+If a tag has to be moved after it was pushed, the tarball hash changes with it, so the
+formula's `sha256` must be recomputed and pushed again or installs fail checksum
+verification.
+
+### Installing and testing the tap
+
+```sh
+brew tap imcarlost/pidcat-repl
+brew install pidcat-repl
+```
+
+Recent Homebrew versions refuse formulae from untrusted third-party taps. The install
+fails with a `Refusing to load formula ... from untrusted tap` error until the tap is
+trusted once per machine:
+
+```sh
+brew trust imcarlost/pidcat-repl
+```
+
+That is a local trust decision each user makes for themselves; there is no way to
+pre-authorize the tap from the publishing side. Getting into homebrew-core instead is not
+realistic for this fork, since core already carries upstream `pidcat` and forks rarely
+meet its notability bar.
+
+After pushing a formula change, `brew update` before reinstalling, or the tap clone under
+`$(brew --repository)/Library/Taps/` will still be on the old commit.

README.md

@@ -7,6 +7,22 @@ entries for a specific application package; this fork adds an interactive,
 full-screen filter UI on top, turning `pidcat` into more of a REPL than a
 one-shot stream.
 
+![Example screen](screen.jpeg)
+
+Install
+-------
+
+Use [Homebrew][2]:
+
+```shell
+brew tap imcarlost/pidcat-repl
+brew trust imcarlost/pidcat-repl
+brew install pidcat-repl
+```
+
+Usage
+----------
+
 During application development you often want to only display log messages
 coming from your app. Unfortunately, because the process ID changes every time
 you deploy to the phone it becomes a challenge to grep for the right thing.
@@ -22,11 +38,6 @@ If you just want the original, non-interactive `pidcat`, use the upstream
 mode](#interactive-mode) below.
 
 
-Here is an example of the output when running for the Google Plus app:
-
-![Example screen](screen.png)
-
-
 Interactive mode
 -----------------
 
@@ -37,7 +48,7 @@ case-insensitively.
 
  * `Backspace` edits the query, `Ctrl-U` clears it.
  * `Ctrl-L` forces a redraw; the view also tracks terminal resizes.
- * `Ctrl-C` or `Ctrl-D` quits and restores your scrollback.
+ * `Esc` or `Ctrl-D` quits and restores your scrollback.
 
 Pass `--plain` to get the original streaming output instead, e.g. for
 `pidcat --plain com.oprah.bees.android | grep Foo`. Piped input or output
@@ -45,26 +56,8 @@ Pass `--plain` to get the original streaming output instead, e.g. for
 uses plain streaming, since there is no terminal to draw the UI on.
 
 
-Install
+Requirements
--------
+------------
-
-This fork isn't packaged anywhere; download `pidcat.py` from this repo and
-place it on your PATH.
-
-The Homebrew and AUR packages below install the upstream, non-interactive
-`pidcat` instead:
-
- *  OS X: Use [Homebrew][2].
-
-         brew install pidcat
-
-    If you need to install the latest development version
-
-        brew unlink pidcat
-        brew install --HEAD pidcat
-
- * Arch Linux : Install the package called `pidcat-git` from the [AUR][4].
-
 
 Make sure that `adb` from the [Android SDK][3] is on your PATH. This script will
 not work unless this is that case. That means, when you type `adb` and press
@@ -92,5 +85,4 @@ sudo apt-get -t focal install coreutils
  [1]: http://jsharkey.org/blog/2009/04/22/modifying-the-android-logcat-stream-for-full-color-debugging/
  [2]: http://brew.sh
  [3]: http://developer.android.com/sdk/
- [4]: https://aur.archlinux.org/packages/pidcat-git/
  [5]: https://github.com/JakeWharton/pidcat

pidcat.py

@@ -33,7 +33,7 @@ import subprocess
 import threading
 from subprocess import PIPE
 
-__version__ = '2.2.0'
+__version__ = '2.4.0'
 
 LOG_LEVELS = 'VDIWEF'
 LOG_LEVELS_MAP = dict([(LOG_LEVELS[i], i) for i in range(len(LOG_LEVELS))])
@@ -321,7 +321,7 @@ def stream(emit):
         linebuf += colorize(' ' * (header_size - 1), bg=WHITE)
         linebuf += ' PID: %s   UID: %s   GIDs: %s' % (line_pid, line_uid, line_gids)
         linebuf += '\n'
-        emit('Process %s created for %s PID: %s' % (line_package, target, line_pid), linebuf)
+        emit('Process %s created for %s PID: %s' % (line_package, target, line_pid), linebuf, is_separator=True)
         last_tag = None # Ensure next log gets a tag printed
 
     dead_pid, dead_pname = parse_death(tag, message)
@@ -331,7 +331,7 @@ def stream(emit):
       linebuf += colorize(' ' * (header_size - 1), bg=RED)
       linebuf += ' Process %s (PID: %s) ended' % (dead_pname, dead_pid)
       linebuf += '\n'
-      emit('Process %s (PID: %s) ended' % (dead_pname, dead_pid), linebuf)
+      emit('Process %s (PID: %s) ended' % (dead_pname, dead_pid), linebuf, is_separator=True)
       last_tag = None # Ensure next log gets a tag printed
 
     # Make sure the backtrace is printed after a native crash
@@ -385,18 +385,24 @@ def stream(emit):
 class InteractiveUI:
   '''Full-screen filter UI: log lines render above a bottom prompt line, and the
   typed query live-filters the scrollback. Every whitespace-separated word must
-  appear in a block's plain text (case-insensitive) for it to be shown.'''
+  appear in a block's plain text (case-insensitive) for it to be shown, except
+  process create/death separators, which always stay visible so filtered runs
+  can still be told apart.'''
 
   MAX_ENTRIES = 10000  # (search_text, block) pairs kept for re-filtering
   MAX_VISIBLE = 5000   # rendered lines kept for the current query
 
   def __init__(self):
     self.lock = threading.Lock()
-    self.entries = collections.deque(maxlen=self.MAX_ENTRIES)
+    self.entries = collections.deque(maxlen=self.MAX_ENTRIES)  # (entry_id, search_lower, block, is_separator)
-    self.visible = []
+    self.visible = []  # (entry_id, line_text)
+    self.next_entry_id = 0
     self.query = ''
     self.status = ''
     self.resized = False
+    self.scroll_offset = 0  # lines scrolled up from the tail; 0 == following the live tail
+    self.hover_row = None      # 0-based screen row the pointer is over, or None
+    self.selected_index = None  # index into self.visible pinned by the last click, or None
     self.rows, self.cols = self._term_size()
 
   def _term_size(self):
@@ -412,26 +418,46 @@ class InteractiveUI:
   def _matches(self, search_lower):
     return all(token in search_lower for token in self.query.lower().split())
 
-  def _append_visible(self, block):
+  def _included(self, search_lower, is_separator):
-    self.visible.extend(block.split('\n'))
+    # Process create/death separators ignore the filter so a run boundary is
-    if len(self.visible) > self.MAX_VISIBLE:
+    # never hidden by an unrelated search.
-      del self.visible[:len(self.visible) - self.MAX_VISIBLE]
+    return is_separator or self._matches(search_lower)
 
-  def emit(self, search_text, block):
+  def _append_visible(self, entry_id, block):
+    new_lines = [(entry_id, line) for line in block.split('\n')]
+    self.visible.extend(new_lines)
+    if self.scroll_offset > 0:
+      # Keep whatever the user is currently looking at in place instead of
+      # letting newly-arrived lines push it down and out of view.
+      self.scroll_offset += len(new_lines)
+    overflow = len(self.visible) - self.MAX_VISIBLE
+    if overflow > 0:
+      del self.visible[:overflow]
+      self.scroll_offset = max(0, self.scroll_offset - overflow)
+      if self.selected_index is not None:
+        self.selected_index -= overflow
+        if self.selected_index < 0:
+          self.selected_index = None
+
+  def emit(self, search_text, block, is_separator=False):
     with self.lock:
+      entry_id = self.next_entry_id
+      self.next_entry_id += 1
       search_lower = search_text.lower()
-      self.entries.append((search_lower, block))
+      self.entries.append((entry_id, search_lower, block, is_separator))
-      if self._matches(search_lower):
+      if self._included(search_lower, is_separator):
-        self._append_visible(block)
+        self._append_visible(entry_id, block)
       self._render()
 
   def set_query(self, query):
     with self.lock:
       self.query = query
       self.visible = []
-      for search_lower, block in self.entries:
+      self.scroll_offset = 0
-        if self._matches(search_lower):
+      self.selected_index = None  # a new search replaces whatever was pinned
-          self._append_visible(block)
+      for entry_id, search_lower, block, is_separator in self.entries:
+        if self._included(search_lower, is_separator):
+          self._append_visible(entry_id, block)
       self._render()
 
   def refresh(self):
@@ -441,42 +467,186 @@ class InteractiveUI:
       width = self.cols  # future indent_wrap calls track the new size
       self._render()
 
+  def _window_bounds(self):
+    '''Returns (start, end, pad): the self.visible slice currently on screen and
+    how many blank padding rows precede it (when there isn't enough content yet
+    to fill the log area).'''
+    log_rows = max(1, self.rows - 2)
+    max_offset = max(0, len(self.visible) - log_rows)
+    if self.scroll_offset > max_offset:
+      self.scroll_offset = max_offset
+    end = len(self.visible) - self.scroll_offset
+    start = max(0, end - log_rows)
+    pad = log_rows - (end - start)
+    return start, end, pad
+
   def _render(self):
     log_rows = max(1, self.rows - 2)
-    lines = self.visible[-log_rows:]
+    start, end, pad = self._window_bounds()
+    window = self.visible[start:end]
     out = ['\x1b[H']
     # Pad above so the log content hugs the prompt, like a terminal.
-    for _ in range(log_rows - len(lines)):
+    for _ in range(pad):
       out.append('\x1b[K\n')
-    for line in lines:
+    for i, (_, line) in enumerate(window):
-      out.append(line + '\x1b[K\n')
+      # Only hint clickability when a filter is active; with no filter a
+      # click is a no-op, so there's nothing to invite the user to click.
+      hovered = self.query and self.hover_row == pad + i
+      selected = self.selected_index == start + i
+      if hovered or selected:
+        out.append('\x1b[7m' + line.replace(RESET, RESET + '\x1b[7m') + RESET + '\x1b[K\n')
+      else:
+        out.append(line + '\x1b[K\n')
     if self.query:
       state = '%d matching lines of %d blocks' % (len(self.visible), len(self.entries))
     else:
       state = '%d blocks' % len(self.entries)
+    if self.scroll_offset > 0:
+      state += ' \xb7 scrolled (End to jump to latest)'
     if self.status:
       state += ' \xb7 ' + self.status
-    separator = ' %s \xb7 type to filter \xb7 ctrl-u clear \xb7 ctrl-c quit' % state
+    hint = ' \xb7 click a line to unfilter' if self.query else ''
+    separator = ' %s \xb7 type to filter \xb7 ctrl-u clear%s \xb7 esc/ctrl-c quit' % (state, hint)
     out.append('\x1b[2m' + separator[:max(0, self.cols - 1)] + '\x1b[0m\x1b[K\n')
     out.append('\x1b[36m❯\x1b[0m ' + self.query + '\x1b[K')
     sys.stdout.write(''.join(out))
     sys.stdout.flush()
 
-  def _drain_pending(self, fd):
+  MOUSE_RE = re.compile(r'^\[<(\d+);(\d+);(\d+)([Mm])$')
-    # Swallow the rest of an escape sequence (arrow keys etc.) we do not handle.
+
-    while select.select([fd], [], [], 0)[0]:
+  def _scroll(self, delta):
-      if not os.read(fd, 64):
+    with self.lock:
+      log_rows = max(1, self.rows - 2)
+      max_offset = max(0, len(self.visible) - log_rows)
+      self.scroll_offset = max(0, min(max_offset, self.scroll_offset + delta))
+      self._render()
+
+  def _handle_click(self, row):
+    with self.lock:
+      if not self.query:  # nothing to unfilter, so clicking is a no-op
+        return
+      log_rows = max(1, self.rows - 2)
+      start, _end, pad = self._window_bounds()
+      if row < 1 or row > log_rows or row <= pad:
+        return
+      idx = start + (row - 1 - pad)
+      if idx < 0 or idx >= len(self.visible):
+        return
+      entry_id = self.visible[idx][0]
+    self._jump_to_entry(entry_id)
+
+  def _handle_hover(self, row):
+    with self.lock:
+      log_rows = max(1, self.rows - 2)
+      _start, _end, pad = self._window_bounds()
+      new_hover = (row - 1) if (1 <= row <= log_rows and row > pad) else None
+      if new_hover == self.hover_row:
+        return
+      self.hover_row = new_hover
+      self._render()
+
+  def _jump_to_entry(self, entry_id):
+    '''Clears the filter, rebuilds the full unfiltered scrollback, and scrolls
+    so the clicked entry is in view with a bit of context above it. The entry's
+    line stays pinned/highlighted until another search starts.'''
+    with self.lock:
+      self.query = ''
+      self.visible = []
+      self.scroll_offset = 0
+      target_index = None
+      for eid, _search_lower, block, _is_separator in self.entries:
+        for line in block.split('\n'):
+          if target_index is None and eid == entry_id:
+            target_index = len(self.visible)
+          self.visible.append((eid, line))
+      overflow = len(self.visible) - self.MAX_VISIBLE
+      if overflow > 0:
+        del self.visible[:overflow]
+        if target_index is not None:
+          target_index -= overflow
+      if target_index is not None and target_index >= 0:
+        self.selected_index = target_index
+        log_rows = max(1, self.rows - 2)
+        max_offset = max(0, len(self.visible) - log_rows)
+        desired_end = target_index + max(1, log_rows // 3)
+        self.scroll_offset = max(0, min(max_offset, len(self.visible) - desired_end))
+      else:
+        self.selected_index = None
+      self._render()
+
+  def _handle_escape(self, seq):
+    m = self.MOUSE_RE.match(seq)
+    if m:
+      button, _col, row, kind = m.groups()
+      if kind != 'M':  # ignore button-release reports
+        return
+      button = int(button)
+      if button == 0:  # left click
+        self._handle_click(int(row))
+      elif button == 35:  # pointer moved, no button held
+        self._handle_hover(int(row))
+      elif button == 64:  # wheel up
+        self._scroll(3)
+      elif button == 65:  # wheel down
+        self._scroll(-3)
+      return
+    log_rows = max(1, self.rows - 2)
+    if seq in ('[A', 'OA'):  # up
+      self._scroll(1)
+    elif seq in ('[B', 'OB'):  # down
+      self._scroll(-1)
+    elif seq == '[5~':  # page up
+      self._scroll(log_rows)
+    elif seq == '[6~':  # page down
+      self._scroll(-log_rows)
+    elif seq in ('[H', '[1~'):  # home
+      self._scroll(10 ** 9)
+    elif seq in ('[F', '[4~'):  # end
+      self._scroll(-(10 ** 9))
+
+  def _read_escape(self, pending, fd, decoder):
+    '''Consumes the sequence following an ESC already pulled from `pending`.
+    Returns (seq, rest_of_pending). seq is None for a standalone Escape
+    keypress (nothing followed it within the grace window), '' when ESC was
+    followed by something unrelated, or the sequence body (e.g. '[A')
+    otherwise.'''
+    if not pending:
+      # Give a fast terminal-generated sequence (arrow keys, mouse reports)
+      # a brief window to arrive before treating this as a lone Escape.
+      if select.select([fd], [], [], 0.01)[0]:
+        data = os.read(fd, 64)
+        if data:
+          pending = decoder.decode(data)
+    if not pending:
+      return None, pending
+    introducer = pending[0]
+    if introducer not in ('[', 'O'):
+      return '', pending
+    seq = introducer
+    pending = pending[1:]
+    while not (seq[-1].isalpha() or seq[-1] == '~'):
+      if not pending:
+        if select.select([fd], [], [], 0.01)[0]:
+          data = os.read(fd, 64)
+          if data:
+            pending += decoder.decode(data)
+            continue
         break
+      seq += pending[0]
+      pending = pending[1:]
+    return seq, pending
 
   def run(self, reader_thread):
     fd = sys.stdin.fileno()
     old_attrs = termios.tcgetattr(fd)
     decoder = codecs.getincrementaldecoder('utf-8')('replace')
     signal.signal(signal.SIGWINCH, lambda *_: setattr(self, 'resized', True))
-    sys.stdout.write('\x1b[?1049h\x1b[?7l\x1b[2J\x1b[H')  # alt screen, no autowrap
+    # Alt screen, no autowrap, mouse click/wheel/motion reporting (SGR encoding).
+    sys.stdout.write('\x1b[?1049h\x1b[?7l\x1b[2J\x1b[H\x1b[?1000h\x1b[?1003h\x1b[?1006h')
     sys.stdout.flush()
     tty.setcbreak(fd)
     reader_thread.start()
+    pending = ''  # decoded characters carried over between reads
     try:
       with self.lock:
         self._render()
@@ -488,35 +658,41 @@ class InteractiveUI:
           self.status = 'adb ended, scrollback still filterable'
           with self.lock:
             self._render()
-        if not select.select([fd], [], [], 0.2)[0]:
+        if not pending:
-          continue
+          if not select.select([fd], [], [], 0.2)[0]:
-        data = os.read(fd, 64)
+            continue
-        if not data:
+          data = os.read(fd, 64)
-          break
+          if not data:
-        for ch in decoder.decode(data):
-          if ch in ('\x7f', '\x08'):  # backspace
-            if self.query:
-              self.set_query(self.query[:-1])
-          elif ch == '\x15':  # ctrl-u
-            if self.query:
-              self.set_query('')
-          elif ch == '\x04':  # ctrl-d
-            return
-          elif ch == '\x0c':  # ctrl-l
-            self.refresh()
-          elif ch == '\x1b':
-            decoder.reset()
-            self._drain_pending(fd)
             break
-          elif ch in ('\r', '\n', '\t'):
+          pending = decoder.decode(data)
-            pass
+          if not pending:
-          elif ch >= ' ':
+            continue
-            self.set_query(self.query + ch)
+        ch, pending = pending[0], pending[1:]
+        if ch in ('\x7f', '\x08'):  # backspace
+          if self.query:
+            self.set_query(self.query[:-1])
+        elif ch == '\x15':  # ctrl-u
+          if self.query:
+            self.set_query('')
+        elif ch == '\x04':  # ctrl-d
+          return
+        elif ch == '\x0c':  # ctrl-l
+          self.refresh()
+        elif ch == '\x1b':
+          seq, pending = self._read_escape(pending, fd, decoder)
+          if seq is None:  # standalone Escape keypress
+            return
+          if seq:
+            self._handle_escape(seq)
+        elif ch in ('\r', '\n', '\t'):
+          pass
+        elif ch >= ' ':
+          self.set_query(self.query + ch)
     except KeyboardInterrupt:
       pass
     finally:
       termios.tcsetattr(fd, termios.TCSADRAIN, old_attrs)
-      sys.stdout.write('\x1b[?7h\x1b[?1049l')
+      sys.stdout.write('\x1b[?1006l\x1b[?1003l\x1b[?1000l\x1b[?7h\x1b[?1049l')
       sys.stdout.flush()
 
 
@@ -537,4 +713,4 @@ else:
     # Die quietly like other unix filters when the downstream reader closes,
     # e.g. `pidcat --plain <pkg> | head`.
     signal.signal(signal.SIGPIPE, signal.SIG_DFL)
-  stream(lambda search_text, block: print(block))
+  stream(lambda search_text, block, is_separator=False: print(block))