diff --git a/scripts/codemap.py b/scripts/codemap.py
index 2ad19c30..0f66d431 100755
--- a/scripts/codemap.py
+++ b/scripts/codemap.py
@@ -897,7 +897,7 @@ def collect_ctx(obj_paths, *,
     return ctx
 
 
-def main_(f, paths, *,
+def main_(ring, paths, *,
         namespace_depth=2,
         labels=[],
         chars=[],
@@ -916,11 +916,11 @@ def main_(f, paths, *,
         label=False,
         no_label=False,
         **args):
-    # give f an writeln function
+    # give ring an writeln function
     def writeln(s=''):
-        f.write(s)
-        f.write('\n')
-    f.writeln = writeln
+        ring.write(s)
+        ring.write('\n')
+    ring.writeln = writeln
 
     # figure out what color should be
     if color == 'auto':
@@ -971,25 +971,25 @@ def main_(f, paths, *,
         # elf/callgraph files
         fs = []
         for path in paths:
-            f_ = openio(path)
-            if f_.buffer.peek(4)[:4] == b'\x7fELF':
-                for f_ in fs:
-                    f_.close()
+            f = openio(path)
+            if f.buffer.peek(4)[:4] == b'\x7fELF':
+                for f in fs:
+                    f.close()
                 raise StopIteration()
-            fs.append(f_)
+            fs.append(f)
 
-        for f_ in fs:
-            with f_:
+        for f in fs:
+            with f:
                 # csv or json? assume json starts with [
-                is_json = (f_.buffer.peek(1)[:1] == b'[')
+                is_json = (f.buffer.peek(1)[:1] == b'[')
 
                 # read csv?
                 if not is_json:
-                    results.extend(csv.DictReader(f_, restval=''))
+                    results.extend(csv.DictReader(f, restval=''))
 
                 # read json?
                 else:
-                    results.extend(json.load(f_))
+                    results.extend(json.load(f))
 
     # fall back to extracting code/stack/ctx info from elf/callgraph files
     except StopIteration:
@@ -1069,29 +1069,29 @@ def main_(f, paths, *,
 
         return f['frame'] + limit
 
-    for k, f_ in functions.items():
-        if 'stack' in f_:
-            if mt.isinf(f_['stack']):
-                f_['limit'] = limitof(k, f_)
+    for k, f in functions.items():
+        if 'stack' in f:
+            if mt.isinf(f['stack']):
+                f['limit'] = limitof(k, f)
             else:
-                f_['limit'] = f_['stack']
+                f['limit'] = f['stack']
 
     # organize into subsystems
     namespace_pattern = re.compile('_*[^_]+(?:_*$)?')
     namespace_slice = slice(namespace_depth if namespace_depth else None)
     subsystems = {}
-    for k, f_ in functions.items():
+    for k, f in functions.items():
         # ignore leading/trailing underscores
-        f_['subsystem'] = ''.join(
+        f['subsystem'] = ''.join(
                 namespace_pattern.findall(k)[
                     namespace_slice])
 
-        if f_['subsystem'] not in subsystems:
-            subsystems[f_['subsystem']] = {'name': f_['subsystem']}
+        if f['subsystem'] not in subsystems:
+            subsystems[f['subsystem']] = {'name': f['subsystem']}
 
     # include ctx in subsystems to give them different colors
-    for _, f_ in functions.items():
-        for a in f_.get('args', []):
+    for _, f in functions.items():
+        for a in f.get('args', []):
             a['subsystem'] = a['name']
 
             if a['subsystem'] not in subsystems:
@@ -1339,9 +1339,9 @@ def main_(f, paths, *,
     # print some summary info
     if not no_header:
         if title:
-            f.writeln(punescape(title, totals['attrs'] | totals))
+            ring.writeln(punescape(title, totals['attrs'] | totals))
         else:
-            f.writeln('code %d stack %s ctx %d' % (
+            ring.writeln('code %d stack %s ctx %d' % (
                         totals.get('code', 0),
                         (lambda s: '∞' if mt.isinf(s) else s)(
                             totals.get('stack', 0)),
@@ -1350,7 +1350,7 @@ def main_(f, paths, *,
     # draw canvas
     for row in range(canvas.height//canvas.yscale):
         line = canvas.draw(row)
-        f.writeln(line)
+        ring.writeln(line)
 
     if (args.get('error_on_recursion')
             and mt.isinf(totals.get('stack', 0))):
diff --git a/scripts/dbgbmap.py b/scripts/dbgbmap.py
index 2de8ac52..9eb7b3fd 100755
--- a/scripts/dbgbmap.py
+++ b/scripts/dbgbmap.py
@@ -4327,7 +4327,7 @@ class BmapBlock:
             }
 
 
-def main_(f, disk, mroots=None, *,
+def main_(ring, disk, mroots=None, *,
         trunk=None,
         block_size=None,
         block_count=None,
@@ -4357,11 +4357,11 @@ def main_(f, disk, mroots=None, *,
         title_usage=False,
         padding=0,
         **args):
-    # give f an writeln function
+    # give ring an writeln function
     def writeln(s=''):
-        f.write(s)
-        f.write('\n')
-    f.writeln = writeln
+        ring.write(s)
+        ring.write('\n')
+    ring.writeln = writeln
 
     # figure out what color should be
     if color == 'auto':
@@ -4435,14 +4435,14 @@ def main_(f, disk, mroots=None, *,
                     None))
 
     # we seek around a bunch, so just keep the disk open
-    with open(disk, 'rb') as f_:
+    with open(disk, 'rb') as f:
         # if block_size is omitted, assume the block device is one big block
         if block_size is None:
-            f_.seek(0, os.SEEK_END)
-            block_size = f_.tell()
+            f.seek(0, os.SEEK_END)
+            block_size = f.tell()
 
         # fetch the filesystem
-        bd = Bd(f_, block_size, block_count)
+        bd = Bd(f, block_size, block_count)
         lfs = Lfs.fetch(bd, mroots, trunk,
                 # don't bother to check things if we're not reporting errors
                 no_ck=not args.get('error_on_corrupt'))
@@ -4455,8 +4455,8 @@ def main_(f, disk, mroots=None, *,
             if lfs.config.geometry is not None:
                 block_count_ = lfs.config.geometry.block_count
             else:
-                f_.seek(0, os.SEEK_END)
-                block_count_ = mt.ceil(f_.tell() / block_size)
+                f.seek(0, os.SEEK_END)
+                block_count_ = mt.ceil(f.tell() / block_size)
 
         # flatten blocks, default to all blocks
         blocks_ = list(
@@ -4755,7 +4755,7 @@ def main_(f, disk, mroots=None, *,
     # print some summary info
     if not no_header:
         if title:
-            f.writeln(punescape(title, {
+            ring.writeln(punescape(title, {
                 'magic': 'littlefs%s' % (
                     '' if lfs.ckmagic() else '?'),
                 'version': 'v%s.%s' % (
@@ -4799,7 +4799,7 @@ def main_(f, disk, mroots=None, *,
                         100*data_count / max(len(bmap), 1)),
             }))
         elif title_littlefs:
-            f.writeln('littlefs%s v%s.%s %sx%s %s w%s.%s, cksum %08x%s' % (
+            ring.writeln('littlefs%s v%s.%s %sx%s %s w%s.%s, cksum %08x%s' % (
                     '' if lfs.ckmagic() else '?',
                     lfs.version.major if lfs.version is not None else '?',
                     lfs.version.minor if lfs.version is not None else '?',
@@ -4810,7 +4810,7 @@ def main_(f, disk, mroots=None, *,
                     lfs.cksum,
                     '' if lfs.ckgcksum() else '?'))
         else:
-            f.writeln('bd %sx%s, %6s mdir, %6s btree, %6s data' % (
+            ring.writeln('bd %sx%s, %6s mdir, %6s btree, %6s data' % (
                     lfs.block_size if lfs.block_size is not None else '?',
                     lfs.block_count if lfs.block_count is not None else '?',
                     '%.1f%%' % (100*mdir_count / max(len(bmap), 1)),
@@ -4820,7 +4820,7 @@ def main_(f, disk, mroots=None, *,
     # draw canvas
     for row in range(canvas.height//canvas.yscale):
         line = canvas.draw(row)
-        f.writeln(line)
+        ring.writeln(line)
 
     if args.get('error_on_corrupt') and corrupted:
         sys.exit(2)
diff --git a/scripts/plot.py b/scripts/plot.py
index 107a21e5..8df22cff 100755
--- a/scripts/plot.py
+++ b/scripts/plot.py
@@ -1152,7 +1152,7 @@ class Grid:
         return grid
 
 
-def main_(f, csv_paths, *,
+def main_(ring, csv_paths, *,
         by=None,
         x=None,
         y=None,
@@ -1187,11 +1187,11 @@ def main_(f, csv_paths, *,
         subplot={},
         subplots=[],
         **args):
-    # give f an writeln function
+    # give ring an writeln function
     def writeln(s=''):
-        f.write(s)
-        f.write('\n')
-    f.writeln = writeln
+        ring.write(s)
+        ring.write('\n')
+    ring.writeln = writeln
 
     # figure out what color should be
     if color == 'auto':
@@ -1643,14 +1643,14 @@ def main_(f, csv_paths, *,
 
     # draw title?
     for line in title_:
-        f.writeln('%*s%s' % (
+        ring.writeln('%*s%s' % (
                 sum(xmargin[:2]), '',
                 line.center(width_-xmargin[1])))
 
     # draw legend_above?
     if legend_above and legend_:
         for i in range(0, len(legend_), legend_cols):
-            f.writeln('%*s%s' % (
+            ring.writeln('%*s%s' % (
                     max(
                         sum(xmargin[:2])
                             + (width_-xmargin[1]
@@ -1665,7 +1665,7 @@ def main_(f, csv_paths, *,
 
     for row in range(height_):
         # draw ylabel?
-        f.write('%s ' % ''.join(
+        ring.write('%s ' % ''.join(
                     ('%*s%s%*s' % (
                             ymargin[-1], '',
                             line.center(height_-sum(ymargin)),
@@ -1688,11 +1688,11 @@ def main_(f, csv_paths, *,
             if subrow < s.ymargin[-1]:
                 # draw subtitle?
                 if subrow < len(s.title_):
-                    f.write('%*s%s' % (
+                    ring.write('%*s%s' % (
                             sum(s.xmargin[:2]), '',
                             s.title_[subrow].center(s.width_)))
                 else:
-                    f.write('%*s%*s' % (
+                    ring.write('%*s%*s' % (
                             sum(s.xmargin[:2]), '',
                             s.width_, ''))
             # draw plot?
@@ -1700,7 +1700,7 @@ def main_(f, csv_paths, *,
                 subrow = subrow-s.ymargin[-1]
 
                 # draw ysublabel?
-                f.write('%-*s' % (
+                ring.write('%-*s' % (
                         s.xmargin[0],
                         '%s ' % ''.join(
                             line.center(s.height_)[subrow]
@@ -1709,25 +1709,25 @@ def main_(f, csv_paths, *,
 
                 # draw yunits?
                 if subrow == 0 and s.yticklabels_ != []:
-                    f.write('%*s' % (
+                    ring.write('%*s' % (
                             s.xmargin[1],
                             ((si2 if s.y2 else si)(s.ylim_[1]) + s.yunits
                                     if s.yticklabels_ is None
                                     else s.yticklabels_[1])
                                 + ' '))
                 elif subrow == s.height_-1 and s.yticklabels_ != []:
-                    f.write('%*s' % (
+                    ring.write('%*s' % (
                             s.xmargin[1],
                             ((si2 if s.y2 else si)(s.ylim_[0]) + s.yunits
                                     if s.yticklabels_ is None
                                     else s.yticklabels_[0])
                                 + ' '))
                 else:
-                    f.write('%*s' % (
+                    ring.write('%*s' % (
                             s.xmargin[1], ''))
 
                 # draw plot!
-                f.write(s.plot_.draw(subrow))
+                ring.write(s.plot_.draw(subrow))
 
             # footer
             else:
@@ -1735,7 +1735,7 @@ def main_(f, csv_paths, *,
 
                 # draw xunits?
                 if subrow < (1 if s.xticklabels_ != [] else 0):
-                    f.write('%*s%-*s%*s%*s' % (
+                    ring.write('%*s%-*s%*s%*s' % (
                             sum(s.xmargin[:2]), '',
                             (5 if s.x2 else 4) + len(s.xunits)
                                 if s.xticklabels_ is None
@@ -1756,11 +1756,11 @@ def main_(f, csv_paths, *,
                 # draw xsublabel?
                 elif (subrow < s.ymargin[1]
                         or subrow-s.ymargin[1] >= len(s.xlabel_)):
-                    f.write('%*s%*s' % (
+                    ring.write('%*s%*s' % (
                             sum(s.xmargin[:2]), '',
                             s.width_, ''))
                 else:
-                    f.write('%*s%s' % (
+                    ring.write('%*s%s' % (
                             sum(s.xmargin[:2]), '',
                             s.xlabel_[subrow-s.ymargin[1]]
                                 .center(s.width_)))
@@ -1770,23 +1770,23 @@ def main_(f, csv_paths, *,
                 and row >= ymargin[-1]
                 and row-ymargin[-1] < len(legend_)):
             j = row-ymargin[-1]
-            f.write(' %s%s%s' % (
+            ring.write(' %s%s%s' % (
                     '\x1b[%sm' % legend_[j][1] if color else '',
                     legend_[j][0],
                     '\x1b[m' if color else ''))
 
-        f.writeln()
+        ring.writeln()
 
     # draw xlabel?
     for line in xlabel_:
-        f.writeln('%*s%s' % (
+        ring.writeln('%*s%s' % (
                 sum(xmargin[:2]), '',
                 line.center(width_-xmargin[1])))
 
     # draw legend below?
     if legend_below and legend_:
         for i in range(0, len(legend_), legend_cols):
-            f.writeln('%*s%s' % (
+            ring.writeln('%*s%s' % (
                     max(
                         sum(xmargin[:2])
                             + (width_-xmargin[1]
diff --git a/scripts/tailpipe.py b/scripts/tailpipe.py
index 8e33afaa..ebceed67 100755
--- a/scripts/tailpipe.py
+++ b/scripts/tailpipe.py
@@ -134,7 +134,6 @@ def main(path='-', *,
     lock = th.Lock()
     event = th.Event()
 
-    # TODO adopt f -> ring name in all scripts?
     def main_(ring):
         try:
             while True:
diff --git a/scripts/tracebd.py b/scripts/tracebd.py
index 9252a862..d5789836 100755
--- a/scripts/tracebd.py
+++ b/scripts/tracebd.py
@@ -1697,7 +1697,6 @@ def main(path='-', *,
     else:
         curve = ft.lru_cache(16)(lambda w, h: list(naive_curve(w, h)))
 
-    # TODO adopt f -> ring name in all scripts?
     def draw__(ring, width, height):
         nonlocal bmap
         # still waiting on bd init
diff --git a/scripts/treemap.py b/scripts/treemap.py
index 5d2f3131..439355aa 100755
--- a/scripts/treemap.py
+++ b/scripts/treemap.py
@@ -908,7 +908,7 @@ def partition_squarify(children, total, x, y, width, height, *,
         i = j
 
 
-def main_(f, csv_paths, *,
+def main_(ring, csv_paths, *,
         by=None,
         fields=None,
         defines=[],
@@ -930,11 +930,11 @@ def main_(f, csv_paths, *,
         label=False,
         no_label=False,
         **args):
-    # give f an writeln function
+    # give ring an writeln function
     def writeln(s=''):
-        f.write(s)
-        f.write('\n')
-    f.writeln = writeln
+        ring.write(s)
+        ring.write('\n')
+    ring.writeln = writeln
 
     # figure out what color should be
     if color == 'auto':
@@ -1215,19 +1215,19 @@ def main_(f, csv_paths, *,
                     stat['mean'], stat['stddev'],
                     stat['min'], stat['max'])
         if title and not no_stats:
-            f.writeln('%s%*s%s' % (
+            ring.writeln('%s%*s%s' % (
                     title_,
                     max(width_-len(stat_)-len(title_), 0), ' ',
                     stat_))
         elif title:
-            f.writeln(title_)
+            ring.writeln(title_)
         elif not no_stats:
-            f.writeln(stat_)
+            ring.writeln(stat_)
 
     # draw canvas
     for row in range(canvas.height//canvas.yscale):
         line = canvas.draw(row)
-        f.writeln(line)
+        ring.writeln(line)
 
 
 def main(csv_paths, *,