From 0ec0ca749598c53a17a3b63b3699515f89a01614 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Wed, 20 Aug 2025 21:19:34 +0200
Subject: [PATCH 1/5] Config files are now specified with -c, rather than via
 filename arguments, because otherwise you get really unhelpful error messages
 when you get things wrong.

---
 build.py                    | 18 +++++++++---------
 lib/config/flags.cc         | 23 ++++++++++++++---------
 lib/config/flags.h          | 23 +++++++++++++++++++----
 scripts/encodedecodetest.sh |  8 ++++----
 4 files changed, 46 insertions(+), 26 deletions(-)

diff --git a/build.py b/build.py
index 71f5274d..9e61d692 100644
--- a/build.py
+++ b/build.py
@@ -28,7 +28,7 @@ else:
         ("acorndfs", "", "--200"),
         ("agat", "", ""),
         ("amiga", "", ""),
-        ("apple2", "", "--140 40track_drive"),
+        ("apple2", "", "--140 -c 40track_drive"),
         ("atarist", "", "--360"),
         ("atarist", "", "--370"),
         ("atarist", "", "--400"),
@@ -38,17 +38,17 @@ else:
         ("atarist", "", "--800"),
         ("atarist", "", "--820"),
         ("bk", "", ""),
-        ("brother", "", "--120 40track_drive"),
+        ("brother", "", "--120 -c 40track_drive"),
         ("brother", "", "--240"),
         (
             "commodore",
             "scripts/commodore1541_test.textpb",
-            "--171 40track_drive",
+            "--171 -c 40track_drive",
         ),
         (
             "commodore",
             "scripts/commodore1541_test.textpb",
-            "--192 40track_drive",
+            "--192 -c 40track_drive",
         ),
         ("commodore", "", "--800"),
         ("commodore", "", "--1620"),
@@ -60,17 +60,17 @@ else:
         ("ibm", "", "--1232"),
         ("ibm", "", "--1440"),
         ("ibm", "", "--1680"),
-        ("ibm", "", "--180 40track_drive"),
-        ("ibm", "", "--160 40track_drive"),
-        ("ibm", "", "--320 40track_drive"),
-        ("ibm", "", "--360 40track_drive"),
+        ("ibm", "", "--180 -c 40track_drive"),
+        ("ibm", "", "--160 -c 40track_drive"),
+        ("ibm", "", "--320 -c 40track_drive"),
+        ("ibm", "", "--360 -c 40track_drive"),
         ("ibm", "", "--720_96"),
         ("ibm", "", "--720_135"),
         ("mac", "scripts/mac400_test.textpb", "--400"),
         ("mac", "scripts/mac800_test.textpb", "--800"),
         ("n88basic", "", ""),
         ("rx50", "", ""),
-        ("tartu", "", "--390 40track_drive"),
+        ("tartu", "", "--390 -c 40track_drive"),
         ("tartu", "", "--780"),
         ("tids990", "", ""),
         ("victor9k", "", "--612"),
diff --git a/lib/config/flags.cc b/lib/config/flags.cc
index bc54262a..f474673b 100644
--- a/lib/config/flags.cc
+++ b/lib/config/flags.cc
@@ -13,17 +13,23 @@ static std::vector<Flag*> all_flags;
 static std::map<const std::string, Flag*> flags_by_name;
 
 static void doHelp();
+static void doLoadConfig(const std::string& filename);
 static void doShowConfig();
 static void doDoc();
 
 static FlagGroup helpGroup;
 static ActionFlag helpFlag = ActionFlag({"--help"}, "Shows the help.", doHelp);
 
-static ActionFlag showConfigFlag = ActionFlag({"--config", "-C"},
+static FlagGroup configGroup;
+static ActionFlag loadConfigFlag({"--config", "-c"},
+    "Reads an internal or external configuration file.",
+    doLoadConfig);
+
+static ActionFlag showConfigFlag({"--show-config", "-C"},
     "Shows the currently set configuration and halts.",
     doShowConfig);
 
-static ActionFlag docFlag = ActionFlag(
+static ActionFlag docFlag(
     {"--doc"}, "Shows the available configuration options and halts.", doDoc);
 
 FlagGroup::FlagGroup()
@@ -182,17 +188,16 @@ void FlagGroup::parseFlags(int argc,
             "non-option parameter '{}' seen (try --help)", *filenames.begin());
 }
 
+static void doLoadConfig(const std::string& filename)
+{
+    globalConfig().readBaseConfigFile(filename);
+}
+
 void FlagGroup::parseFlagsWithConfigFiles(int argc,
     const char* argv[],
     const std::map<std::string, const ConfigProto*>& configFiles)
 {
-    parseFlags(argc,
-        argv,
-        [&](const auto& filename)
-        {
-            globalConfig().readBaseConfigFile(filename);
-            return true;
-        });
+    FlagGroup({this, &configGroup}).parseFlags(argc, argv);
 }
 
 void FlagGroup::checkInitialised() const
diff --git a/lib/config/flags.h b/lib/config/flags.h
index 67be675f..d8b96af4 100644
--- a/lib/config/flags.h
+++ b/lib/config/flags.h
@@ -83,13 +83,23 @@ public:
         const std::string helptext,
         std::function<void(void)> callback):
         Flag(names, helptext),
-        _callback(callback)
+        _voidCallback(callback),
+        _hasArgument(false)
+    {
+    }
+
+    ActionFlag(const std::vector<std::string>& names,
+        const std::string helptext,
+        std::function<void(const std::string&)> callback):
+        Flag(names, helptext),
+        _callback(callback),
+        _hasArgument(true)
     {
     }
 
     bool hasArgument() const override
     {
-        return false;
+        return _hasArgument;
     }
 
     const std::string defaultValueAsString() const override
@@ -99,11 +109,16 @@ public:
 
     void set(const std::string& value) override
     {
-        _callback();
+        if (_hasArgument)
+            _callback(value);
+        else
+            _voidCallback();
     }
 
 private:
-    const std::function<void(void)> _callback;
+    const std::function<void(const std::string&)> _callback;
+    const std::function<void(void)> _voidCallback;
+    bool _hasArgument;
 };
 
 class SettableFlag : public Flag
diff --git a/scripts/encodedecodetest.sh b/scripts/encodedecodetest.sh
index 80842e24..d8cbf5b9 100755
--- a/scripts/encodedecodetest.sh
+++ b/scripts/encodedecodetest.sh
@@ -14,10 +14,10 @@ destfile=$dir/dest.img
 
 dd if=/dev/urandom of=$srcfile bs=1048576 count=2 2>&1
 
-echo $fluxengine write $format -i $srcfile -d $fluxfile --drive.rotational_period_ms=200 $flags
-$fluxengine write $format -i $srcfile -d $fluxfile --drive.rotational_period_ms=200 $flags
-echo $fluxengine read $format -s $fluxfile -o $destfile --drive.rotational_period_ms=200 $flags
-$fluxengine read $format -s $fluxfile -o $destfile --drive.rotational_period_ms=200 $flags
+echo $fluxengine write -c $format -i $srcfile -d $fluxfile --drive.rotational_period_ms=200 $flags
+$fluxengine write -c $format -i $srcfile -d $fluxfile --drive.rotational_period_ms=200 $flags
+echo $fluxengine read -c $format -s $fluxfile -o $destfile --drive.rotational_period_ms=200 $flags
+$fluxengine read -c $format -s $fluxfile -o $destfile --drive.rotational_period_ms=200 $flags
 if [ ! -s $destfile ]; then
 	echo "Zero length output file!" >&2
 	exit 1

From ec16931f3a76e11003d3a06f2a2dc6d3d25eba65 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Wed, 20 Aug 2025 21:23:02 +0200
Subject: [PATCH 2/5] Update documentation for -c.

---
 doc/disk-40track_drive.md |  2 +-
 doc/disk-acornadfs.md     | 10 +++++-----
 doc/disk-acorndfs.md      |  8 ++++----
 doc/disk-aeslanier.md     |  2 +-
 doc/disk-agat.md          |  4 ++--
 doc/disk-amiga.md         |  4 ++--
 doc/disk-ampro.md         |  4 ++--
 doc/disk-apple2.md        |  8 ++++----
 doc/disk-apple2_drive.md  |  2 +-
 doc/disk-atarist.md       | 32 ++++++++++++++---------------
 doc/disk-bk.md            |  4 ++--
 doc/disk-brother.md       |  8 ++++----
 doc/disk-commodore.md     | 18 ++++++++---------
 doc/disk-eco1.md          |  2 +-
 doc/disk-epsonpf10.md     |  2 +-
 doc/disk-f85.md           |  2 +-
 doc/disk-fb100.md         |  2 +-
 doc/disk-hplif.md         | 16 +++++++--------
 doc/disk-ibm.md           | 42 +++++++++++++++++++--------------------
 doc/disk-icl30.md         |  2 +-
 doc/disk-mac.md           |  8 ++++----
 doc/disk-micropolis.md    |  4 ++--
 doc/disk-mx.md            |  8 ++++----
 doc/disk-n88basic.md      |  4 ++--
 doc/disk-northstar.md     | 12 +++++------
 doc/disk-psos.md          |  4 ++--
 doc/disk-rolandd20.md     |  4 ++--
 doc/disk-rx50.md          |  4 ++--
 doc/disk-shugart_drive.md |  2 +-
 doc/disk-smaky6.md        |  2 +-
 doc/disk-tartu.md         |  8 ++++----
 doc/disk-tids990.md       |  4 ++--
 doc/disk-tiki.md          |  8 ++++----
 doc/disk-victor9k.md      |  8 ++++----
 doc/disk-zilogmcz.md      |  2 +-
 doc/using.md              | 16 +++++++--------
 scripts/mkdoc.cc          |  2 +-
 37 files changed, 137 insertions(+), 137 deletions(-)

diff --git a/doc/disk-40track_drive.md b/doc/disk-40track_drive.md
index 203628f8..39b65558 100644
--- a/doc/disk-40track_drive.md
+++ b/doc/disk-40track_drive.md
@@ -10,6 +10,6 @@ no way to detect this automatically.
 For example:
 
 ```
-fluxengine read ibm --180 40track_drive
+fluxengine read -c ibm --180 40track_drive
 ```
 
diff --git a/doc/disk-acornadfs.md b/doc/disk-acornadfs.md
index 2e63eff3..2b969bcc 100644
--- a/doc/disk-acornadfs.md
+++ b/doc/disk-acornadfs.md
@@ -31,9 +31,9 @@ they might require nudging as the side order can't be reliably autodetected.
 
 To read:
 
-  - `fluxengine read acornadfs --160 -s drive:0 -o acornadfs.img`
-  - `fluxengine read acornadfs --320 -s drive:0 -o acornadfs.img`
-  - `fluxengine read acornadfs --640 -s drive:0 -o acornadfs.img`
-  - `fluxengine read acornadfs --800 -s drive:0 -o acornadfs.img`
-  - `fluxengine read acornadfs --1600 -s drive:0 -o acornadfs.img`
+  - `fluxengine read -c acornadfs --160 -s drive:0 -o acornadfs.img`
+  - `fluxengine read -c acornadfs --320 -s drive:0 -o acornadfs.img`
+  - `fluxengine read -c acornadfs --640 -s drive:0 -o acornadfs.img`
+  - `fluxengine read -c acornadfs --800 -s drive:0 -o acornadfs.img`
+  - `fluxengine read -c acornadfs --1600 -s drive:0 -o acornadfs.img`
 
diff --git a/doc/disk-acorndfs.md b/doc/disk-acorndfs.md
index a36b0ddc..6f9e42db 100644
--- a/doc/disk-acorndfs.md
+++ b/doc/disk-acorndfs.md
@@ -24,13 +24,13 @@ requires a bit of fiddling as they have the same tracks on twice.
 
 To read:
 
-  - `fluxengine read acorndfs --100 -s drive:0 -o acorndfs.img`
-  - `fluxengine read acorndfs --200 -s drive:0 -o acorndfs.img`
+  - `fluxengine read -c acorndfs --100 -s drive:0 -o acorndfs.img`
+  - `fluxengine read -c acorndfs --200 -s drive:0 -o acorndfs.img`
 
 To write:
 
-  - `fluxengine write acorndfs --100 -d drive:0 -i acorndfs.img`
-  - `fluxengine write acorndfs --200 -d drive:0 -i acorndfs.img`
+  - `fluxengine write -c acorndfs --100 -d drive:0 -i acorndfs.img`
+  - `fluxengine write -c acorndfs --200 -d drive:0 -i acorndfs.img`
 
 ## References
 
diff --git a/doc/disk-aeslanier.md b/doc/disk-aeslanier.md
index 73073fc3..7cfe2411 100644
--- a/doc/disk-aeslanier.md
+++ b/doc/disk-aeslanier.md
@@ -37,7 +37,7 @@ based on what looks right. If anyone knows _anything_ about these disks,
 
 To read:
 
-  - `fluxengine read aeslanier -s drive:0 -o aeslanier.img`
+  - `fluxengine read -c aeslanier -s drive:0 -o aeslanier.img`
 
 ## References
 
diff --git a/doc/disk-agat.md b/doc/disk-agat.md
index dc2b579d..57cf416e 100644
--- a/doc/disk-agat.md
+++ b/doc/disk-agat.md
@@ -20,11 +20,11 @@ profile.
 
 To read:
 
-  - `fluxengine read agat -s drive:0 -o agat.img`
+  - `fluxengine read -c agat -s drive:0 -o agat.img`
 
 To write:
 
-  - `fluxengine write agat -d drive:0 -i agat.img`
+  - `fluxengine write -c agat -d drive:0 -i agat.img`
 
 ## References
 
diff --git a/doc/disk-amiga.md b/doc/disk-amiga.md
index fe40ed94..5ab77d78 100644
--- a/doc/disk-amiga.md
+++ b/doc/disk-amiga.md
@@ -26,11 +26,11 @@ distinctly subpar and not particularly good at detecting errors.
 
 To read:
 
-  - `fluxengine read amiga -s drive:0 -o amiga.adf`
+  - `fluxengine read -c amiga -s drive:0 -o amiga.adf`
 
 To write:
 
-  - `fluxengine write amiga -d drive:0 -i amiga.adf`
+  - `fluxengine write -c amiga -d drive:0 -i amiga.adf`
 
 ## References
 
diff --git a/doc/disk-ampro.md b/doc/disk-ampro.md
index f1b51f32..e55076f5 100644
--- a/doc/disk-ampro.md
+++ b/doc/disk-ampro.md
@@ -43,8 +43,8 @@ kayinfo.lbr
 
 To read:
 
-  - `fluxengine read ampro --400 -s drive:0 -o ampro.img`
-  - `fluxengine read ampro --800 -s drive:0 -o ampro.img`
+  - `fluxengine read -c ampro --400 -s drive:0 -o ampro.img`
+  - `fluxengine read -c ampro --800 -s drive:0 -o ampro.img`
 
 ## References
 
diff --git a/doc/disk-apple2.md b/doc/disk-apple2.md
index d866a497..fd1eee32 100644
--- a/doc/disk-apple2.md
+++ b/doc/disk-apple2.md
@@ -58,13 +58,13 @@ volume.
 
 To read:
 
-  - `fluxengine read apple2 --140 -s drive:0 -o apple2.img`
-  - `fluxengine read apple2 --640 -s drive:0 -o apple2.img`
+  - `fluxengine read -c apple2 --140 -s drive:0 -o apple2.img`
+  - `fluxengine read -c apple2 --640 -s drive:0 -o apple2.img`
 
 To write:
 
-  - `fluxengine write apple2 --140 -d drive:0 -i apple2.img`
-  - `fluxengine write apple2 --640 -d drive:0 -i apple2.img`
+  - `fluxengine write -c apple2 --140 -d drive:0 -i apple2.img`
+  - `fluxengine write -c apple2 --640 -d drive:0 -i apple2.img`
 
 ## References
 
diff --git a/doc/disk-apple2_drive.md b/doc/disk-apple2_drive.md
index e631d138..6fa952e4 100644
--- a/doc/disk-apple2_drive.md
+++ b/doc/disk-apple2_drive.md
@@ -11,6 +11,6 @@ connector.
 For example:
 
 ```
-fluxengine read apple2 --160 apple2_drive
+fluxengine read -c apple2 --160 apple2_drive
 ```
 
diff --git a/doc/disk-atarist.md b/doc/disk-atarist.md
index 25f3e11e..76aa1ef2 100644
--- a/doc/disk-atarist.md
+++ b/doc/disk-atarist.md
@@ -29,25 +29,25 @@ Be aware that many PC drives (including mine) won't do the 82 track formats.
 
 To read:
 
-  - `fluxengine read atarist --360 -s drive:0 -o atarist.img`
-  - `fluxengine read atarist --370 -s drive:0 -o atarist.img`
-  - `fluxengine read atarist --400 -s drive:0 -o atarist.img`
-  - `fluxengine read atarist --410 -s drive:0 -o atarist.img`
-  - `fluxengine read atarist --720 -s drive:0 -o atarist.img`
-  - `fluxengine read atarist --740 -s drive:0 -o atarist.img`
-  - `fluxengine read atarist --800 -s drive:0 -o atarist.img`
-  - `fluxengine read atarist --820 -s drive:0 -o atarist.img`
+  - `fluxengine read -c atarist --360 -s drive:0 -o atarist.img`
+  - `fluxengine read -c atarist --370 -s drive:0 -o atarist.img`
+  - `fluxengine read -c atarist --400 -s drive:0 -o atarist.img`
+  - `fluxengine read -c atarist --410 -s drive:0 -o atarist.img`
+  - `fluxengine read -c atarist --720 -s drive:0 -o atarist.img`
+  - `fluxengine read -c atarist --740 -s drive:0 -o atarist.img`
+  - `fluxengine read -c atarist --800 -s drive:0 -o atarist.img`
+  - `fluxengine read -c atarist --820 -s drive:0 -o atarist.img`
 
 To write:
 
-  - `fluxengine write atarist --360 -d drive:0 -i atarist.img`
-  - `fluxengine write atarist --370 -d drive:0 -i atarist.img`
-  - `fluxengine write atarist --400 -d drive:0 -i atarist.img`
-  - `fluxengine write atarist --410 -d drive:0 -i atarist.img`
-  - `fluxengine write atarist --720 -d drive:0 -i atarist.img`
-  - `fluxengine write atarist --740 -d drive:0 -i atarist.img`
-  - `fluxengine write atarist --800 -d drive:0 -i atarist.img`
-  - `fluxengine write atarist --820 -d drive:0 -i atarist.img`
+  - `fluxengine write -c atarist --360 -d drive:0 -i atarist.img`
+  - `fluxengine write -c atarist --370 -d drive:0 -i atarist.img`
+  - `fluxengine write -c atarist --400 -d drive:0 -i atarist.img`
+  - `fluxengine write -c atarist --410 -d drive:0 -i atarist.img`
+  - `fluxengine write -c atarist --720 -d drive:0 -i atarist.img`
+  - `fluxengine write -c atarist --740 -d drive:0 -i atarist.img`
+  - `fluxengine write -c atarist --800 -d drive:0 -i atarist.img`
+  - `fluxengine write -c atarist --820 -d drive:0 -i atarist.img`
 
 ## References
 
diff --git a/doc/disk-bk.md b/doc/disk-bk.md
index fa18d96a..e26bfd12 100644
--- a/doc/disk-bk.md
+++ b/doc/disk-bk.md
@@ -22,9 +22,9 @@ on what was available at the time, with the same format on both.
 
 To read:
 
-  - `fluxengine read bk -s drive:0 -o bk800.img`
+  - `fluxengine read -c bk -s drive:0 -o bk800.img`
 
 To write:
 
-  - `fluxengine write bk -d drive:0 -i bk800.img`
+  - `fluxengine write -c bk -d drive:0 -i bk800.img`
 
diff --git a/doc/disk-brother.md b/doc/disk-brother.md
index 6e12dced..ba041e56 100644
--- a/doc/disk-brother.md
+++ b/doc/disk-brother.md
@@ -44,13 +44,13 @@ investigate.
 
 To read:
 
-  - `fluxengine read brother --120 -s drive:0 -o brother.img`
-  - `fluxengine read brother --240 -s drive:0 -o brother.img`
+  - `fluxengine read -c brother --120 -s drive:0 -o brother.img`
+  - `fluxengine read -c brother --240 -s drive:0 -o brother.img`
 
 To write:
 
-  - `fluxengine write brother --120 -d drive:0 -i brother.img`
-  - `fluxengine write brother --240 -d drive:0 -i brother.img`
+  - `fluxengine write -c brother --120 -d drive:0 -i brother.img`
+  - `fluxengine write -c brother --240 -d drive:0 -i brother.img`
 
 Dealing with misaligned disks
 -----------------------------
diff --git a/doc/disk-commodore.md b/doc/disk-commodore.md
index c2ad45f9..98021111 100644
--- a/doc/disk-commodore.md
+++ b/doc/disk-commodore.md
@@ -54,18 +54,18 @@ A CMD FD2000 disk (a popular third-party Commodore disk drive)
 
 To read:
 
-  - `fluxengine read commodore --171 -s drive:0 -o commodore.d64`
-  - `fluxengine read commodore --192 -s drive:0 -o commodore.d64`
-  - `fluxengine read commodore --800 -s drive:0 -o commodore.d64`
-  - `fluxengine read commodore --1042 -s drive:0 -o commodore.d64`
-  - `fluxengine read commodore --1620 -s drive:0 -o commodore.d64`
+  - `fluxengine read -c commodore --171 -s drive:0 -o commodore.d64`
+  - `fluxengine read -c commodore --192 -s drive:0 -o commodore.d64`
+  - `fluxengine read -c commodore --800 -s drive:0 -o commodore.d64`
+  - `fluxengine read -c commodore --1042 -s drive:0 -o commodore.d64`
+  - `fluxengine read -c commodore --1620 -s drive:0 -o commodore.d64`
 
 To write:
 
-  - `fluxengine write commodore --171 -d drive:0 -i commodore.d64`
-  - `fluxengine write commodore --192 -d drive:0 -i commodore.d64`
-  - `fluxengine write commodore --800 -d drive:0 -i commodore.d64`
-  - `fluxengine write commodore --1620 -d drive:0 -i commodore.d64`
+  - `fluxengine write -c commodore --171 -d drive:0 -i commodore.d64`
+  - `fluxengine write -c commodore --192 -d drive:0 -i commodore.d64`
+  - `fluxengine write -c commodore --800 -d drive:0 -i commodore.d64`
+  - `fluxengine write -c commodore --1620 -d drive:0 -i commodore.d64`
 
 ## References
 
diff --git a/doc/disk-eco1.md b/doc/disk-eco1.md
index f31ca3a1..8159611a 100644
--- a/doc/disk-eco1.md
+++ b/doc/disk-eco1.md
@@ -33,7 +33,7 @@ images.
 
 To read:
 
-  - `fluxengine read eco1 -s drive:0 -o eco1.img`
+  - `fluxengine read -c eco1 -s drive:0 -o eco1.img`
 
 ## References
 
diff --git a/doc/disk-epsonpf10.md b/doc/disk-epsonpf10.md
index 4f272f09..772001ab 100644
--- a/doc/disk-epsonpf10.md
+++ b/doc/disk-epsonpf10.md
@@ -15,5 +15,5 @@ format itself is yet another IBM scheme variant.
 
 To read:
 
-  - `fluxengine read epsonpf10 -s drive:0 -o epsonpf10.img`
+  - `fluxengine read -c epsonpf10 -s drive:0 -o epsonpf10.img`
 
diff --git a/doc/disk-f85.md b/doc/disk-f85.md
index 3f99b343..b4041f86 100644
--- a/doc/disk-f85.md
+++ b/doc/disk-f85.md
@@ -36,7 +36,7 @@ touch](https://github.com/davidgiven/fluxengine/issues/new).
 
 To read:
 
-  - `fluxengine read f85 -s drive:0 -o f85.img`
+  - `fluxengine read -c f85 -s drive:0 -o f85.img`
 
 ## References
 
diff --git a/doc/disk-fb100.md b/doc/disk-fb100.md
index 2ba81422..8d788758 100644
--- a/doc/disk-fb100.md
+++ b/doc/disk-fb100.md
@@ -30,7 +30,7 @@ I don't have access to one of those disks.
 
 To read:
 
-  - `fluxengine read fb100 -s drive:0 -o fb100.img`
+  - `fluxengine read -c fb100 -s drive:0 -o fb100.img`
 
 ## References
 
diff --git a/doc/disk-hplif.md b/doc/disk-hplif.md
index f5cf22f6..c59720d1 100644
--- a/doc/disk-hplif.md
+++ b/doc/disk-hplif.md
@@ -23,17 +23,17 @@ encoding scheme.
 
 To read:
 
-  - `fluxengine read hplif --264 -s drive:0 -o hplif.img`
-  - `fluxengine read hplif --608 -s drive:0 -o hplif.img`
-  - `fluxengine read hplif --616 -s drive:0 -o hplif.img`
-  - `fluxengine read hplif --770 -s drive:0 -o hplif.img`
+  - `fluxengine read -c hplif --264 -s drive:0 -o hplif.img`
+  - `fluxengine read -c hplif --608 -s drive:0 -o hplif.img`
+  - `fluxengine read -c hplif --616 -s drive:0 -o hplif.img`
+  - `fluxengine read -c hplif --770 -s drive:0 -o hplif.img`
 
 To write:
 
-  - `fluxengine write hplif --264 -d drive:0 -i hplif.img`
-  - `fluxengine write hplif --608 -d drive:0 -i hplif.img`
-  - `fluxengine write hplif --616 -d drive:0 -i hplif.img`
-  - `fluxengine write hplif --770 -d drive:0 -i hplif.img`
+  - `fluxengine write -c hplif --264 -d drive:0 -i hplif.img`
+  - `fluxengine write -c hplif --608 -d drive:0 -i hplif.img`
+  - `fluxengine write -c hplif --616 -d drive:0 -i hplif.img`
+  - `fluxengine write -c hplif --770 -d drive:0 -i hplif.img`
 
 ## References
 
diff --git a/doc/disk-ibm.md b/doc/disk-ibm.md
index 742be528..bd83f6cd 100644
--- a/doc/disk-ibm.md
+++ b/doc/disk-ibm.md
@@ -55,30 +55,30 @@ image format. FluxEngine will use these parameters.
 
 To read:
 
-  - `fluxengine read ibm --auto -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --160 -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --180 -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --320 -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --360 -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --720_96 -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --720_135 -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --1200 -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --1232 -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --1440 -s drive:0 -o ibm.img`
-  - `fluxengine read ibm --1680 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --auto -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --160 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --180 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --320 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --360 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --720_96 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --720_135 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --1200 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --1232 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --1440 -s drive:0 -o ibm.img`
+  - `fluxengine read -c ibm --1680 -s drive:0 -o ibm.img`
 
 To write:
 
-  - `fluxengine write ibm --160 -d drive:0 -i ibm.img`
-  - `fluxengine write ibm --180 -d drive:0 -i ibm.img`
-  - `fluxengine write ibm --320 -d drive:0 -i ibm.img`
-  - `fluxengine write ibm --360 -d drive:0 -i ibm.img`
-  - `fluxengine write ibm --720_96 -d drive:0 -i ibm.img`
-  - `fluxengine write ibm --720_135 -d drive:0 -i ibm.img`
-  - `fluxengine write ibm --1200 -d drive:0 -i ibm.img`
-  - `fluxengine write ibm --1232 -d drive:0 -i ibm.img`
-  - `fluxengine write ibm --1440 -d drive:0 -i ibm.img`
-  - `fluxengine write ibm --1680 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --160 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --180 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --320 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --360 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --720_96 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --720_135 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --1200 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --1232 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --1440 -d drive:0 -i ibm.img`
+  - `fluxengine write -c ibm --1680 -d drive:0 -i ibm.img`
 
 Mixed-format disks
 ------------------
diff --git a/doc/disk-icl30.md b/doc/disk-icl30.md
index a5333a8d..237fb1f5 100644
--- a/doc/disk-icl30.md
+++ b/doc/disk-icl30.md
@@ -15,5 +15,5 @@ track! Other than that it's another IBM scheme variation.
 
 To read:
 
-  - `fluxengine read icl30 -s drive:0 -o icl30.img`
+  - `fluxengine read -c icl30 -s drive:0 -o icl30.img`
 
diff --git a/doc/disk-mac.md b/doc/disk-mac.md
index 655c5175..459aadb4 100644
--- a/doc/disk-mac.md
+++ b/doc/disk-mac.md
@@ -47,13 +47,13 @@ standard for disk images is to omit it. If you want them, specify that you want
 
 To read:
 
-  - `fluxengine read mac --400 -s drive:0 -o mac.dsk`
-  - `fluxengine read mac --800 -s drive:0 -o mac.dsk`
+  - `fluxengine read -c mac --400 -s drive:0 -o mac.dsk`
+  - `fluxengine read -c mac --800 -s drive:0 -o mac.dsk`
 
 To write:
 
-  - `fluxengine write mac --400 -d drive:0 -i mac.dsk`
-  - `fluxengine write mac --800 -d drive:0 -i mac.dsk`
+  - `fluxengine write -c mac --400 -d drive:0 -i mac.dsk`
+  - `fluxengine write -c mac --800 -d drive:0 -i mac.dsk`
 
 ## References
 
diff --git a/doc/disk-micropolis.md b/doc/disk-micropolis.md
index a5c2576f..f7e59151 100644
--- a/doc/disk-micropolis.md
+++ b/doc/disk-micropolis.md
@@ -63,11 +63,11 @@ need to apply extra options to change the format if desired.
 
 To read:
 
-  - `fluxengine read micropolis -s drive:0 -o micropolis.img`
+  - `fluxengine read -c micropolis -s drive:0 -o micropolis.img`
 
 To write:
 
-  - `fluxengine write micropolis -d drive:0 -i micropolis.img`
+  - `fluxengine write -c micropolis -d drive:0 -i micropolis.img`
 
 ## References
 
diff --git a/doc/disk-mx.md b/doc/disk-mx.md
index 0e3102e9..d881f370 100644
--- a/doc/disk-mx.md
+++ b/doc/disk-mx.md
@@ -52,10 +52,10 @@ Words are all stored little-endian.
 
 To read:
 
-  - `fluxengine read mx --110 -s drive:0 -o mx.img`
-  - `fluxengine read mx --220ds -s drive:0 -o mx.img`
-  - `fluxengine read mx --220ss -s drive:0 -o mx.img`
-  - `fluxengine read mx --440 -s drive:0 -o mx.img`
+  - `fluxengine read -c mx --110 -s drive:0 -o mx.img`
+  - `fluxengine read -c mx --220ds -s drive:0 -o mx.img`
+  - `fluxengine read -c mx --220ss -s drive:0 -o mx.img`
+  - `fluxengine read -c mx --440 -s drive:0 -o mx.img`
 
 ## References
 
diff --git a/doc/disk-n88basic.md b/doc/disk-n88basic.md
index 749b256c..5538f368 100644
--- a/doc/disk-n88basic.md
+++ b/doc/disk-n88basic.md
@@ -18,9 +18,9 @@ boot ROM could only read single density data.)
 
 To read:
 
-  - `fluxengine read n88basic -s drive:0 -o n88basic.img`
+  - `fluxengine read -c n88basic -s drive:0 -o n88basic.img`
 
 To write:
 
-  - `fluxengine write n88basic -d drive:0 -i n88basic.img`
+  - `fluxengine write -c n88basic -d drive:0 -i n88basic.img`
 
diff --git a/doc/disk-northstar.md b/doc/disk-northstar.md
index 26386574..dfc4d471 100644
--- a/doc/disk-northstar.md
+++ b/doc/disk-northstar.md
@@ -31,15 +31,15 @@ equivalent to .img images.
 
 To read:
 
-  - `fluxengine read northstar --87 -s drive:0 -o northstar.nsi`
-  - `fluxengine read northstar --175 -s drive:0 -o northstar.nsi`
-  - `fluxengine read northstar --350 -s drive:0 -o northstar.nsi`
+  - `fluxengine read -c northstar --87 -s drive:0 -o northstar.nsi`
+  - `fluxengine read -c northstar --175 -s drive:0 -o northstar.nsi`
+  - `fluxengine read -c northstar --350 -s drive:0 -o northstar.nsi`
 
 To write:
 
-  - `fluxengine write northstar --87 -d drive:0 -i northstar.nsi`
-  - `fluxengine write northstar --175 -d drive:0 -i northstar.nsi`
-  - `fluxengine write northstar --350 -d drive:0 -i northstar.nsi`
+  - `fluxengine write -c northstar --87 -d drive:0 -i northstar.nsi`
+  - `fluxengine write -c northstar --175 -d drive:0 -i northstar.nsi`
+  - `fluxengine write -c northstar --350 -d drive:0 -i northstar.nsi`
 
 ## References
 
diff --git a/doc/disk-psos.md b/doc/disk-psos.md
index 27df0224..66933130 100644
--- a/doc/disk-psos.md
+++ b/doc/disk-psos.md
@@ -24,9 +24,9 @@ and, oddly, swapped sides.
 
 To read:
 
-  - `fluxengine read psos -s drive:0 -o pme.img`
+  - `fluxengine read -c psos -s drive:0 -o pme.img`
 
 To write:
 
-  - `fluxengine write psos -d drive:0 -i pme.img`
+  - `fluxengine write -c psos -d drive:0 -i pme.img`
 
diff --git a/doc/disk-rolandd20.md b/doc/disk-rolandd20.md
index 92eaa1dc..b8ad4040 100644
--- a/doc/disk-rolandd20.md
+++ b/doc/disk-rolandd20.md
@@ -40,9 +40,9 @@ for assistance with this!
 
 To read:
 
-  - `fluxengine read rolandd20 -s drive:0 -o rolandd20.img`
+  - `fluxengine read -c rolandd20 -s drive:0 -o rolandd20.img`
 
 To write:
 
-  - `fluxengine write rolandd20 -d drive:0 -i rolandd20.img`
+  - `fluxengine write -c rolandd20 -d drive:0 -i rolandd20.img`
 
diff --git a/doc/disk-rx50.md b/doc/disk-rx50.md
index d39a5ca2..888feaec 100644
--- a/doc/disk-rx50.md
+++ b/doc/disk-rx50.md
@@ -15,9 +15,9 @@ vanilla single-sided IBM scheme variation.
 
 To read:
 
-  - `fluxengine read rx50 -s drive:0 -o rx50.img`
+  - `fluxengine read -c rx50 -s drive:0 -o rx50.img`
 
 To write:
 
-  - `fluxengine write rx50 -d drive:0 -i rx50.img`
+  - `fluxengine write -c rx50 -d drive:0 -i rx50.img`
 
diff --git a/doc/disk-shugart_drive.md b/doc/disk-shugart_drive.md
index 086e1d39..a1f8685a 100644
--- a/doc/disk-shugart_drive.md
+++ b/doc/disk-shugart_drive.md
@@ -10,6 +10,6 @@ on Greaseweazle hardware.
 For example:
 
 ```
-fluxengine read ibm --720 shugart_drive
+fluxengine read -c ibm --720 shugart_drive
 ```
 
diff --git a/doc/disk-smaky6.md b/doc/disk-smaky6.md
index 03dec9f8..4f3ccfc6 100644
--- a/doc/disk-smaky6.md
+++ b/doc/disk-smaky6.md
@@ -26,7 +26,7 @@ this is completely correct, so don't trust it!
 
 To read:
 
-  - `fluxengine read smaky6 -s drive:0 -o smaky6.img`
+  - `fluxengine read -c smaky6 -s drive:0 -o smaky6.img`
 
 ## References
 
diff --git a/doc/disk-tartu.md b/doc/disk-tartu.md
index 4831d4db..5fb0d049 100644
--- a/doc/disk-tartu.md
+++ b/doc/disk-tartu.md
@@ -34,13 +34,13 @@ FluxEngine supports reading and writing Tartu disks with CP/M filesystem access.
 
 To read:
 
-  - `fluxengine read tartu --390 -s drive:0 -o tartu.img`
-  - `fluxengine read tartu --780 -s drive:0 -o tartu.img`
+  - `fluxengine read -c tartu --390 -s drive:0 -o tartu.img`
+  - `fluxengine read -c tartu --780 -s drive:0 -o tartu.img`
 
 To write:
 
-  - `fluxengine write tartu --390 -d drive:0 -i tartu.img`
-  - `fluxengine write tartu --780 -d drive:0 -i tartu.img`
+  - `fluxengine write -c tartu --390 -d drive:0 -i tartu.img`
+  - `fluxengine write -c tartu --780 -d drive:0 -i tartu.img`
 
 ## References
 
diff --git a/doc/disk-tids990.md b/doc/disk-tids990.md
index e25dea48..c429b674 100644
--- a/doc/disk-tids990.md
+++ b/doc/disk-tids990.md
@@ -26,11 +26,11 @@ FluxEngine will read and write these (but only the DSDD MFM variant).
 
 To read:
 
-  - `fluxengine read tids990 -s drive:0 -o tids990.img`
+  - `fluxengine read -c tids990 -s drive:0 -o tids990.img`
 
 To write:
 
-  - `fluxengine write tids990 -d drive:0 -i tids990.img`
+  - `fluxengine write -c tids990 -d drive:0 -i tids990.img`
 
 ## References
 
diff --git a/doc/disk-tiki.md b/doc/disk-tiki.md
index bcf4cf89..6f92e19e 100644
--- a/doc/disk-tiki.md
+++ b/doc/disk-tiki.md
@@ -20,8 +20,8 @@ on the precise format.
 
 To read:
 
-  - `fluxengine read tiki --90 -s drive:0 -o tiki.img`
-  - `fluxengine read tiki --200 -s drive:0 -o tiki.img`
-  - `fluxengine read tiki --400 -s drive:0 -o tiki.img`
-  - `fluxengine read tiki --800 -s drive:0 -o tiki.img`
+  - `fluxengine read -c tiki --90 -s drive:0 -o tiki.img`
+  - `fluxengine read -c tiki --200 -s drive:0 -o tiki.img`
+  - `fluxengine read -c tiki --400 -s drive:0 -o tiki.img`
+  - `fluxengine read -c tiki --800 -s drive:0 -o tiki.img`
 
diff --git a/doc/disk-victor9k.md b/doc/disk-victor9k.md
index 82e69814..47e98e15 100644
--- a/doc/disk-victor9k.md
+++ b/doc/disk-victor9k.md
@@ -46,13 +46,13 @@ FluxEngine can read and write both the single-sided and double-sided variants.
 
 To read:
 
-  - `fluxengine read victor9k --612 -s drive:0 -o victor9k.img`
-  - `fluxengine read victor9k --1224 -s drive:0 -o victor9k.img`
+  - `fluxengine read -c victor9k --612 -s drive:0 -o victor9k.img`
+  - `fluxengine read -c victor9k --1224 -s drive:0 -o victor9k.img`
 
 To write:
 
-  - `fluxengine write victor9k --612 -d drive:0 -i victor9k.img`
-  - `fluxengine write victor9k --1224 -d drive:0 -i victor9k.img`
+  - `fluxengine write -c victor9k --612 -d drive:0 -i victor9k.img`
+  - `fluxengine write -c victor9k --1224 -d drive:0 -i victor9k.img`
 
 ## References
 
diff --git a/doc/disk-zilogmcz.md b/doc/disk-zilogmcz.md
index 7d2cb218..7f530f74 100644
--- a/doc/disk-zilogmcz.md
+++ b/doc/disk-zilogmcz.md
@@ -31,7 +31,7 @@ system.
 
 To read:
 
-  - `fluxengine read zilogmcz -s drive:0 -o zilogmcz.img`
+  - `fluxengine read -c zilogmcz -s drive:0 -o zilogmcz.img`
 
 ## References
 
diff --git a/doc/using.md b/doc/using.md
index 9b83828b..3fd5ee73 100644
--- a/doc/using.md
+++ b/doc/using.md
@@ -82,16 +82,16 @@ Here are some sample invocations:
 ```
 # Read an PC 1440kB disk, producing a disk image with the default name
 # (ibm.img)
-$ fluxengine read ibm --1440
+$ fluxengine read -c ibm --1440
 
 # Write a PC 1440kB disk to drive 1
-$ fluxengine write ibm --1440 -i image.img -d drive:1
+$ fluxengine write -c ibm --1440 -i image.img -d drive:1
 
 # Read a Eco1 CP/M disk, making a copy of the flux into a file
-$ fluxengine read eco1 --copy-flux-to copy.flux -o eco1.ldbs
+$ fluxengine read -c eco1 --copy-flux-to copy.flux -o eco1.ldbs
 
 # Rerun the decode from the flux file, tweaking the parameters
-$ fluxengine read eco1 -s copy.flux -o eco1.ldbs --cylinders=1
+$ fluxengine read -c eco1 -s copy.flux -o eco1.ldbs --cylinders=1
 ```
 
 ### Configuration
@@ -146,14 +146,14 @@ different task. Run each one with `--help` to get a full list of
 (non-configuration-setting) options; this describes only basic usage of the
 more common tools.
 
-  - `fluxengine read <profile> <options> -s <flux source> -o <image output>`
+  - `fluxengine read -c <profile> <options> -s <flux source> -o <image output>`
 
     Reads flux (possibly from a disk) and decodes it into a file system image.
     `<profile>` is a reference to an internal input configuration file
     describing the format. `<options>` may be any combination of options
     defined by the profile.
 
-  - `fluxengine write <profile> -i <image input> -d <flux destination>`
+  - `fluxengine write -c <profile> -i <image input> -d <flux destination>`
 
     Reads a filesystem image and encodes it into flux (possibly writing to a
     disk). `<profile>` is a reference to an internal output configuration file
@@ -489,7 +489,7 @@ containing valuable historical data, and you want to read them.
 Typically I do this:
 
 ```
-$ fluxengine read brother240 -s drive:0 -o brother.img --copy-flux-to=brother.flux --decoder.write_csv_to=brother.csv
+$ fluxengine read -c brother240 -s drive:0 -o brother.img --copy-flux-to=brother.flux --decoder.write_csv_to=brother.csv
 ```
 
 This will read the disk in drive 0 and write out an information CSV file. It'll
@@ -499,7 +499,7 @@ settings, I can rerun the decode without having to physically touch the disk
 like this:
 
 ```
-$ fluxengine read brother -s brother.flux -o brother.img --decoder.write_csv_to=brother.csv
+$ fluxengine read -c brother -s brother.flux -o brother.img --decoder.write_csv_to=brother.csv
 ```
 
 Apart from being drastically faster, this avoids touching the (potentially
diff --git a/scripts/mkdoc.cc b/scripts/mkdoc.cc
index a116134e..9f98d7c2 100644
--- a/scripts/mkdoc.cc
+++ b/scripts/mkdoc.cc
@@ -28,7 +28,7 @@ static void addExample(std::vector<std::string>& examples,
     else
         return;
 
-    r += fmt::format(" {}", name);
+    r += fmt::format(" -c {}", name);
     if (format)
         r += fmt::format(" --{}", format->name());
 

From e2a6fbcf3cc1c99bf6d672d8b83c7abb80be7d6b Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Wed, 20 Aug 2025 21:30:06 +0200
Subject: [PATCH 3/5] Update a few places which used -c for other purposes.

---
 src/fe-analysedriveresponse.cc | 13 +++++++------
 src/fe-inspect.cc              |  9 +++++----
 src/fe-seek.cc                 |  2 +-
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/src/fe-analysedriveresponse.cc b/src/fe-analysedriveresponse.cc
index 6b1f2c19..52dd14ea 100644
--- a/src/fe-analysedriveresponse.cc
+++ b/src/fe-analysedriveresponse.cc
@@ -22,9 +22,7 @@ static StringFlag destFlux({"--dest", "-d"},
         globalConfig().setFluxSink(value);
     });
 
-static IntFlag destTrack({"--cylinder", "-c"}, "track to write to", 0);
-
-static IntFlag destHead({"--head", "-h"}, "head to write to", 0);
+static StringFlag destTracks({"--tracks", "-t"}, "tracks to write to", "c0h0");
 
 static DoubleFlag minInterval(
     {"--min-interval-us"}, "Minimum pulse interval", 2.0);
@@ -251,11 +249,14 @@ int mainAnalyseDriveResponse(int argc, const char* argv[])
 
     if (globalConfig()->flux_sink().type() != FLUXTYPE_DRIVE)
         error("this only makes sense with a real disk drive");
+    auto tracks = parseCylinderHeadsString(destTracks);
+    if (tracks.size() != 1)
+        error("you must specify exactly one track");
 
     usbSetDrive(globalConfig()->drive().drive(),
         globalConfig()->drive().high_density(),
         globalConfig()->drive().index_mode());
-    usbSeek(destTrack);
+    usbSeek(tracks[0].cylinder);
 
     std::cout << "Measuring rotational speed...\n";
     nanoseconds_t period = usbGetRotationalPeriod(0);
@@ -291,12 +292,12 @@ int mainAnalyseDriveResponse(int argc, const char* argv[])
                 outFluxmap.appendPulse();
             }
 
-            usbWrite(destHead, outFluxmap.rawBytes(), 0);
+            usbWrite(tracks[0].head, outFluxmap.rawBytes(), 0);
 
             /* Read the test pattern in again. */
 
             Fluxmap inFluxmap;
-            inFluxmap.appendBytes(usbRead(destHead, true, period, 0));
+            inFluxmap.appendBytes(usbRead(tracks[0].head, true, period, 0));
 
             /* Compute histogram. */
 
diff --git a/src/fe-inspect.cc b/src/fe-inspect.cc
index d66cddc4..9bb78123 100644
--- a/src/fe-inspect.cc
+++ b/src/fe-inspect.cc
@@ -21,9 +21,7 @@ static StringFlag sourceFlux({"--source", "-s"},
         globalConfig().setFluxSource(value);
     });
 
-static IntFlag trackFlag({"--cylinder", "-c"}, "Track to read.", 0);
-
-static IntFlag headFlag({"--head", "-h"}, "Head to read.", 0);
+static StringFlag destTracks({"--tracks", "-t"}, "tracks to write to", "c0h0");
 
 static SettableFlag dumpFluxFlag(
     {"--dump-flux", "-F"}, "Dump raw magnetic disk flux.");
@@ -135,7 +133,10 @@ int mainInspect(int argc, const char* argv[])
     flags.parseFlagsWithConfigFiles(argc, argv, {});
 
     auto fluxSource = FluxSource::create(globalConfig());
-    const auto fluxmap = fluxSource->readFlux(trackFlag, headFlag)->next();
+    auto tracks = parseCylinderHeadsString(destTracks);
+    if (tracks.size() != 1)
+        error("you must specify exactly one track");
+    const auto fluxmap = fluxSource->readFlux(tracks[0])->next();
 
     std::cout << fmt::format("0x{:x} bytes of data in {:.3f}ms\n",
         fluxmap->bytes(),
diff --git a/src/fe-seek.cc b/src/fe-seek.cc
index 8f933716..038f6169 100644
--- a/src/fe-seek.cc
+++ b/src/fe-seek.cc
@@ -16,7 +16,7 @@ static StringFlag sourceFlux({"-s", "--source"},
         globalConfig().setFluxSource(value);
     });
 
-static IntFlag track({"--cylinder", "-c"}, "track to seek to", 0);
+static IntFlag track({"--cylinder", "-t"}, "track to seek to", 0);
 
 extern const std::map<std::string, std::string> readables;
 

From 9062a531f32124f0fd9b171402347308fcfcf3e4 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Thu, 21 Aug 2025 00:53:50 +0200
Subject: [PATCH 4/5] Migrate the 40track etc extension configs to actual
 options. Add the ability to have --group=value options to make this cleaner.

---
 build.py                           |  18 ++--
 doc/disk-40track_drive.md          |   2 +-
 doc/disk-apple2_drive.md           |   2 +-
 doc/disk-shugart_drive.md          |   2 +-
 lib/config/config.cc               | 145 ++++++++++++-----------------
 lib/config/config.h                |  22 ++++-
 lib/config/config.proto            |   3 +-
 lib/config/flags.cc                |   3 +-
 src/formats/40track_drive.textpb   |  22 -----
 src/formats/_global_options.textpb |  77 +++++++++++++++
 src/formats/apple2_drive.textpb    |  29 ------
 src/formats/build.py               |   4 +-
 src/formats/shugart_drive.textpb   |  22 -----
 tests/options.cc                   |  12 +--
 14 files changed, 175 insertions(+), 188 deletions(-)
 delete mode 100644 src/formats/40track_drive.textpb
 create mode 100644 src/formats/_global_options.textpb
 delete mode 100644 src/formats/apple2_drive.textpb
 delete mode 100644 src/formats/shugart_drive.textpb

diff --git a/build.py b/build.py
index 9e61d692..38b0c9cb 100644
--- a/build.py
+++ b/build.py
@@ -28,7 +28,7 @@ else:
         ("acorndfs", "", "--200"),
         ("agat", "", ""),
         ("amiga", "", ""),
-        ("apple2", "", "--140 -c 40track_drive"),
+        ("apple2", "", "--140 --drivetype=40"),
         ("atarist", "", "--360"),
         ("atarist", "", "--370"),
         ("atarist", "", "--400"),
@@ -38,17 +38,17 @@ else:
         ("atarist", "", "--800"),
         ("atarist", "", "--820"),
         ("bk", "", ""),
-        ("brother", "", "--120 -c 40track_drive"),
+        ("brother", "", "--120 --drivetype=40"),
         ("brother", "", "--240"),
         (
             "commodore",
             "scripts/commodore1541_test.textpb",
-            "--171 -c 40track_drive",
+            "--171 --drivetype=40",
         ),
         (
             "commodore",
             "scripts/commodore1541_test.textpb",
-            "--192 -c 40track_drive",
+            "--192 --drivetype=40",
         ),
         ("commodore", "", "--800"),
         ("commodore", "", "--1620"),
@@ -60,17 +60,17 @@ else:
         ("ibm", "", "--1232"),
         ("ibm", "", "--1440"),
         ("ibm", "", "--1680"),
-        ("ibm", "", "--180 -c 40track_drive"),
-        ("ibm", "", "--160 -c 40track_drive"),
-        ("ibm", "", "--320 -c 40track_drive"),
-        ("ibm", "", "--360 -c 40track_drive"),
+        ("ibm", "", "--180 --drivetype=40"),
+        ("ibm", "", "--160 --drivetype=40"),
+        ("ibm", "", "--320 --drivetype=40"),
+        ("ibm", "", "--360 --drivetype=40"),
         ("ibm", "", "--720_96"),
         ("ibm", "", "--720_135"),
         ("mac", "scripts/mac400_test.textpb", "--400"),
         ("mac", "scripts/mac800_test.textpb", "--800"),
         ("n88basic", "", ""),
         ("rx50", "", ""),
-        ("tartu", "", "--390 -c 40track_drive"),
+        ("tartu", "", "--390 --drivetype=40"),
         ("tartu", "", "--780"),
         ("tids990", "", ""),
         ("victor9k", "", "--612"),
diff --git a/doc/disk-40track_drive.md b/doc/disk-40track_drive.md
index 39b65558..203628f8 100644
--- a/doc/disk-40track_drive.md
+++ b/doc/disk-40track_drive.md
@@ -10,6 +10,6 @@ no way to detect this automatically.
 For example:
 
 ```
-fluxengine read -c ibm --180 40track_drive
+fluxengine read ibm --180 40track_drive
 ```
 
diff --git a/doc/disk-apple2_drive.md b/doc/disk-apple2_drive.md
index 6fa952e4..e631d138 100644
--- a/doc/disk-apple2_drive.md
+++ b/doc/disk-apple2_drive.md
@@ -11,6 +11,6 @@ connector.
 For example:
 
 ```
-fluxengine read -c apple2 --160 apple2_drive
+fluxengine read apple2 --160 apple2_drive
 ```
 
diff --git a/doc/disk-shugart_drive.md b/doc/disk-shugart_drive.md
index a1f8685a..086e1d39 100644
--- a/doc/disk-shugart_drive.md
+++ b/doc/disk-shugart_drive.md
@@ -10,6 +10,6 @@ on Greaseweazle hardware.
 For example:
 
 ```
-fluxengine read -c ibm --720 shugart_drive
+fluxengine read ibm --720 shugart_drive
 ```
 
diff --git a/lib/config/config.cc b/lib/config/config.cc
index 3a96df88..cec45b20 100644
--- a/lib/config/config.cc
+++ b/lib/config/config.cc
@@ -5,6 +5,7 @@
 #include "lib/core/utils.h"
 #include <fstream>
 #include <google/protobuf/text_format.h>
+#include <fmt/ranges.h>
 
 static Config config;
 
@@ -181,35 +182,8 @@ ConfigProto* Config::combined()
     {
         _combinedConfig = _baseConfig;
 
-        /* First apply any standalone options. */
-
-        std::set<std::string> options = _appliedOptions;
-        for (const auto& option : _baseConfig.option())
-        {
-            if (options.find(option.name()) != options.end())
-            {
-                _combinedConfig.MergeFrom(option.config());
-                options.erase(option.name());
-            }
-        }
-
-        /* Then apply any group options. */
-
-        for (auto& group : _baseConfig.option_group())
-        {
-            const OptionProto* selectedOption = &*group.option().begin();
-
-            for (auto& option : group.option())
-            {
-                if (options.find(option.name()) != options.end())
-                {
-                    selectedOption = &option;
-                    options.erase(option.name());
-                }
-            }
-
-            _combinedConfig.MergeFrom(selectedOption->config());
-        }
+        for (const auto& optionInfo : _appliedOptions)
+            _combinedConfig.MergeFrom(optionInfo.option->config());
 
         /* Add in the user overrides. */
 
@@ -241,51 +215,27 @@ std::vector<std::string> Config::validate()
 {
     std::vector<std::string> results;
 
-    std::set<std::string> optionNames = _appliedOptions;
-    std::set<const OptionProto*> appliedOptions;
-    for (const auto& option : _baseConfig.option())
-    {
-        if (optionNames.find(option.name()) != optionNames.end())
+    /* Ensure that only one item in each group is set. */
+
+    std::map<const OptionGroupProto*, const OptionProto*> optionsByGroup;
+    for (auto [group, option, hasArgument] : _appliedOptions)
+        if (group)
         {
-            appliedOptions.insert(&option);
-            optionNames.erase(option.name());
+            auto& o = optionsByGroup[group];
+            if (o)
+                results.push_back(
+                    fmt::format("multiple mutually exclusive values set for "
+                                "group '{}': valid values are: {}",
+                        group->comment(),
+                        fmt::join(std::views::transform(
+                                      group->option(), &OptionProto::name),
+                            ", ")));
+            o = option;
         }
-    }
-
-    /* Then apply any group options. */
-
-    for (auto& group : _baseConfig.option_group())
-    {
-        int count = 0;
-
-        for (auto& option : group.option())
-        {
-            if (optionNames.find(option.name()) != optionNames.end())
-            {
-                optionNames.erase(option.name());
-                appliedOptions.insert(&option);
-
-                count++;
-                if (count == 2)
-                    results.push_back(
-                        fmt::format("multiple mutually exclusive options set "
-                                    "for group '{}'",
-                            group.comment()));
-            }
-        }
-    }
-
-    /* Check for unknown options. */
-
-    if (!optionNames.empty())
-    {
-        for (auto& name : optionNames)
-            results.push_back(fmt::format("'{}' is not a known option", name));
-    }
 
     /* Check option requirements. */
 
-    for (auto& option : appliedOptions)
+    for (auto [group, option, hasArgument] : _appliedOptions)
     {
         try
         {
@@ -360,11 +310,12 @@ void Config::readBaseConfig(std::string data)
         error("couldn't load external config proto");
 }
 
-const OptionProto& Config::findOption(const std::string& optionName)
+Config::OptionInfo Config::findOption(
+    const std::string& name, const std::string value)
 {
     const OptionProto* found = nullptr;
 
-    auto searchOptionList = [&](auto& optionList)
+    auto searchOptionList = [&](auto& optionList, const std::string& optionName)
     {
         for (const auto& option : optionList)
         {
@@ -377,17 +328,39 @@ const OptionProto& Config::findOption(const std::string& optionName)
         return false;
     };
 
-    if (searchOptionList(base()->option()))
-        return *found;
+    /* First look for any group names which match. */
+
+    if (!value.empty())
+        for (const auto& optionGroup : base()->option_group())
+            if (optionGroup.name() == name)
+            {
+                /* The option must therefore be one of these. */
+
+                if (searchOptionList(optionGroup.option(), value))
+                    return {&optionGroup, found, true};
+
+                throw OptionNotFoundException(fmt::format(
+                    "value {} is not valid for option {}; valid values are: {}",
+                    value,
+                    name,
+                    fmt::join(std::views::transform(
+                                  optionGroup.option(), &OptionProto::name),
+                        ", ")));
+            }
+
+    /* Now search for individual options. */
+
+    if (searchOptionList(base()->option(), name))
+        return {nullptr, found, false};
 
     for (const auto& optionGroup : base()->option_group())
     {
-        if (searchOptionList(optionGroup.option()))
-            return *found;
+        if (optionGroup.name().empty())
+            if (searchOptionList(optionGroup.option(), name))
+                return {nullptr, found, false};
     }
 
-    throw OptionNotFoundException(
-        fmt::format("option {} not found", optionName));
+    throw OptionNotFoundException(fmt::format("option {} not found", name));
 }
 
 void Config::checkOptionValid(const OptionProto& option)
@@ -445,22 +418,20 @@ bool Config::isOptionValid(const OptionProto& option)
     }
 }
 
-bool Config::isOptionValid(std::string option)
-{
-    return isOptionValid(findOption(option));
-}
-
-void Config::applyOption(const OptionProto& option)
+void Config::applyOption(const OptionInfo& optionInfo)
 {
+    auto* option = optionInfo.option;
     log(OptionLogMessage{
-        option.has_message() ? option.message() : option.comment()});
+        option->has_message() ? option->message() : option->comment()});
 
-    _appliedOptions.insert(option.name());
+    _appliedOptions.insert(optionInfo);
 }
 
-void Config::applyOption(std::string option)
+bool Config::applyOption(const std::string& name, const std::string value)
 {
-    applyOption(findOption(option));
+    auto optionInfo = findOption(name, value);
+    applyOption(optionInfo);
+    return optionInfo.usesValue;
 }
 
 void Config::clearOptions()
diff --git a/lib/config/config.h b/lib/config/config.h
index 5025347e..e3026336 100644
--- a/lib/config/config.h
+++ b/lib/config/config.h
@@ -66,6 +66,18 @@ struct FluxConstructor
 
 class Config
 {
+private:
+    struct OptionInfo
+    {
+        bool operator==(const OptionInfo& other) const = default;
+        std::strong_ordering operator<=>(
+            const OptionInfo& other) const = default;
+
+        const OptionGroupProto* group;
+        const OptionProto* option;
+        bool usesValue;
+    };
+
 public:
     /* Direct access to the various proto layers. */
 
@@ -124,12 +136,12 @@ public:
     /* Option management: look up an option by name, determine whether an option
      * is valid, and apply an option. */
 
-    const OptionProto& findOption(const std::string& option);
+    OptionInfo findOption(
+        const std::string& name, const std::string value = "");
     void checkOptionValid(const OptionProto& option);
     bool isOptionValid(const OptionProto& option);
-    bool isOptionValid(std::string option);
-    void applyOption(const OptionProto& option);
-    void applyOption(std::string option);
+    void applyOption(const OptionInfo& optionInfo);
+    bool applyOption(const std::string& name, const std::string value = "");
     void clearOptions();
 
     /* Adjust overall inputs and outputs. */
@@ -165,7 +177,7 @@ private:
     ConfigProto _baseConfig;
     ConfigProto _overridesConfig;
     ConfigProto _combinedConfig;
-    std::set<std::string> _appliedOptions;
+    std::set<OptionInfo> _appliedOptions;
     bool _configValid;
 
     FluxSourceProto _verificationFluxSourceProto;
diff --git a/lib/config/config.proto b/lib/config/config.proto
index e98c85ec..9db8f972 100644
--- a/lib/config/config.proto
+++ b/lib/config/config.proto
@@ -73,5 +73,6 @@ message OptionProto
 message OptionGroupProto
 {
     optional string comment = 1 [(help) = "help text for option group"];
-    repeated OptionProto option = 2;
+    optional string name = 2 [(help) = "option group name"];
+    repeated OptionProto option = 3;
 }
diff --git a/lib/config/flags.cc b/lib/config/flags.cc
index f474673b..f61b0dac 100644
--- a/lib/config/flags.cc
+++ b/lib/config/flags.cc
@@ -158,7 +158,7 @@ std::vector<std::string> FlagGroup::parseFlagsWithFilenames(int argc,
                         index += usesthat;
                     }
                     else
-                        globalConfig().applyOption(path);
+                        usesthat = globalConfig().applyOption(path, value);
                 }
                 else
                     error("unrecognised flag '-{}'; try --help", key);
@@ -197,6 +197,7 @@ void FlagGroup::parseFlagsWithConfigFiles(int argc,
     const char* argv[],
     const std::map<std::string, const ConfigProto*>& configFiles)
 {
+    globalConfig().readBaseConfigFile("_global_options");
     FlagGroup({this, &configGroup}).parseFlags(argc, argv);
 }
 
diff --git a/src/formats/40track_drive.textpb b/src/formats/40track_drive.textpb
deleted file mode 100644
index 39b16f95..00000000
--- a/src/formats/40track_drive.textpb
+++ /dev/null
@@ -1,22 +0,0 @@
-comment: 'Adjust configuration for a 40-track drive'
-is_extension: true
-
-documentation:
-<<<
-This is an extension profile; adding this to the command line will configure
-FluxEngine to read from 40-track, 48tpi 5.25" drives. You have to tell it because there is
-no way to detect this automatically.
-
-For example:
-
-```
-fluxengine read ibm --180 40track_drive
-```
->>>
-
-drive {
-    tracks: "c0-40h0-1"
-    drive_type: DRIVETYPE_40TRACK
-}
-
-
diff --git a/src/formats/_global_options.textpb b/src/formats/_global_options.textpb
new file mode 100644
index 00000000..7619f5da
--- /dev/null
+++ b/src/formats/_global_options.textpb
@@ -0,0 +1,77 @@
+comment: 'Options which can be applied everywhere.'
+is_extension: true
+
+option_group {
+	comment: "Drive type"
+    name: "drivetype"
+
+	option {
+		name: "80"
+		comment: '80 track drive'
+        set_by_default: true
+
+		config {
+		}
+	}
+
+	option {
+		name: "40"
+		comment: '40 track drive'
+
+		config {
+            drive {
+                tracks: "c0-40h0-1"
+                drive_type: DRIVETYPE_40TRACK
+            }
+		}
+	}
+
+	option {
+		name: "160"
+		comment: '160 track Apple II drive'
+
+		config {
+            drive {
+                tracks: "c0-159h0"
+                drive_type: DRIVETYPE_APPLE2
+            }
+		}
+	}
+}
+
+option_group {
+    comment: 'Bus interface'
+    name: "bus"
+
+	option {
+		name: "pc"
+		comment: 'PC drive interface'
+        set_by_default: true
+    }
+
+	option {
+		name: "shugart"
+		comment: 'Shugart bus interface (only on Greaseweazle)'
+
+		config {
+            usb {
+                greaseweazle {
+                    bus_type: SHUGART
+                }
+            }
+        }
+    }
+
+	option {
+		name: "appleii"
+		comment: 'Apple II bus interface (only on Greaseweazle)'
+
+		config {
+            usb {
+                greaseweazle {
+                    bus_type: APPLE2
+                }
+            }
+		}
+	}
+}
diff --git a/src/formats/apple2_drive.textpb b/src/formats/apple2_drive.textpb
deleted file mode 100644
index 64532bcc..00000000
--- a/src/formats/apple2_drive.textpb
+++ /dev/null
@@ -1,29 +0,0 @@
-comment: 'Adjust configuration for a 40-track Apple II drive'
-is_extension: true
-
-documentation:
-<<<
-This is an extension profile; adding this to the command line will configure
-FluxEngine to adjust the pinout and track spacing to work with an Apple II
-drive.  This only works on Greaseweazle hardware and requires a custom
-connector.
-
-For example:
-
-```
-fluxengine read apple2 --160 apple2_drive
-```
->>>
-
-usb {
-    greaseweazle {
-        bus_type: APPLE2
-    }
-}
-
-drive {
-    tracks: "c0-159h0"
-    drive_type: DRIVETYPE_APPLE2
-}
-
-
diff --git a/src/formats/build.py b/src/formats/build.py
index b4689560..99f0591e 100644
--- a/src/formats/build.py
+++ b/src/formats/build.py
@@ -3,14 +3,13 @@ from build.c import cxxlibrary
 from scripts.build import protoencode
 
 formats = [
-    "40track_drive",
+    "_global_options",
     "acornadfs",
     "acorndfs",
     "aeslanier",
     "agat",
     "amiga",
     "ampro",
-    "apple2_drive",
     "apple2",
     "atarist",
     "bk",
@@ -33,7 +32,6 @@ formats = [
     "psos",
     "rolandd20",
     "rx50",
-    "shugart_drive",
     "smaky6",
     "tartu",
     "ti99",
diff --git a/src/formats/shugart_drive.textpb b/src/formats/shugart_drive.textpb
deleted file mode 100644
index 8734c2fc..00000000
--- a/src/formats/shugart_drive.textpb
+++ /dev/null
@@ -1,22 +0,0 @@
-comment: 'Adjust configuration for a Shugart drive'
-is_extension: true
-
-documentation:
-<<<
-This is an extension profile; adding this to the command line will configure
-FluxEngine to adjust the pinout to work with a Shugart drive. This only works
-on Greaseweazle hardware.
-
-For example:
-
-```
-fluxengine read ibm --720 shugart_drive
-```
->>>
-
-usb {
-    greaseweazle {
-        bus_type: SHUGART
-    }
-}
-
diff --git a/tests/options.cc b/tests/options.cc
index 547e9021..37f8af64 100644
--- a/tests/options.cc
+++ b/tests/options.cc
@@ -55,14 +55,14 @@ static void test_option_validity()
         }
 	)M");
 
-    AssertThat(
-        globalConfig().isOptionValid(globalConfig().findOption("option1")),
+    AssertThat(globalConfig().isOptionValid(
+                   *globalConfig().findOption("option1").option),
         Equals(true));
-    AssertThat(
-        globalConfig().isOptionValid(globalConfig().findOption("option2")),
+    AssertThat(globalConfig().isOptionValid(
+                   *globalConfig().findOption("option2").option),
         Equals(false));
-    AssertThat(
-        globalConfig().isOptionValid(globalConfig().findOption("option3")),
+    AssertThat(globalConfig().isOptionValid(
+                   *globalConfig().findOption("option3").option),
         Equals(true));
 }
 

From 979b55017856d424425a89edf6d5f2350a315a90 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Thu, 21 Aug 2025 01:19:19 +0200
Subject: [PATCH 5/5] Looks like our string_view fix hasn't worked --- tweak.

---
 scripts/mkdocindex.cc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/scripts/mkdocindex.cc b/scripts/mkdocindex.cc
index 7a3bb716..dbbb3db5 100644
--- a/scripts/mkdocindex.cc
+++ b/scripts/mkdocindex.cc
@@ -43,8 +43,9 @@ int main(int argc, const char* argv[])
             {
                 const auto* descriptor =
                     FilesystemProto::FilesystemType_descriptor();
-                std::string name =
-                    descriptor->FindValueByNumber(fs.type())->name();
+                auto name =
+                    (std::string)descriptor->FindValueByNumber(fs.type())
+                        ->name();
 
                 filesystems.insert(name);
             }