refactor: rearrange/resort args (#1376)

* clean up Cargo.toml

* some small cleanup

* refactor: group together similar args in the help generation and code

This groups together related arguments in both the help text and the
code itself.

* update changelog

* clippy

* builder pattern instead

CHANGELOG.md

@@ -14,7 +14,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changes
 
-- [#1344](https://github.com/ClementTsang/bottom/pull/1344): Change the `group` command line argument to `group_processes` for consistency with the config file option.
+- [#1344](https://github.com/ClementTsang/bottom/pull/1344): Change the `group` command line-argument to `group_processes` for consistency with the config file option.
+- [#1376](https://github.com/ClementTsang/bottom/pull/1376): Group together related command-line arguments in `-h` and `--help`.
 
 ### Bug Fixes
 

Cargo.lock

@@ -239,18 +239,18 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "clap"
-version = "4.4.11"
+version = "4.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfaff671f6b22ca62406885ece523383b9b64022e341e53e009a62ebc47a45f2"
+checksum = "33e92c5c1a78c62968ec57dbc2440366a2d6e5a23faf829970ff1585dc6b18e2"
 dependencies = [
  "clap_builder",
 ]
 
 [[package]]
 name = "clap_builder"
-version = "4.4.11"
+version = "4.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a216b506622bb1d316cd51328dce24e07bdff4a6128a47c7e7fad11878d5adbb"
+checksum = "f4323769dc8a61e2c39ad7dc26f6f2800524691a44d74fe3d1071a5c24db6370"
 dependencies = [
  "anstream",
  "anstyle",
@@ -261,9 +261,9 @@ dependencies = [
 
 [[package]]
 name = "clap_complete"
-version = "4.4.5"
+version = "4.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a51919c5608a32e34ea1d6be321ad070065e17613e168c5b6977024290f2630b"
+checksum = "97aeaa95557bd02f23fbb662f981670c3d20c5a26e69f7354b28f57092437fcd"
 dependencies = [
  "clap",
 ]
@@ -296,9 +296,9 @@ checksum = "702fc72eb24e5a1e48ce58027a675bc24edd52096d5397d4aea7c6dd9eca0bd1"
 
 [[package]]
 name = "clap_mangen"
-version = "0.2.15"
+version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d3be86020147691e1d2ef58f75346a3d4d94807bfc473e377d52f09f0f7d77f7"
+checksum = "10b5db60b3310cdb376fbeb8826e875a38080d0c61bdec0a91a3da8338948736"
 dependencies = [
  "clap",
  "roff",

Cargo.toml

@@ -64,23 +64,20 @@ strip = false
 
 [features]
 battery = ["starship-battery"]
-gpu = ["nvidia"]
 nvidia = ["nvml-wrapper"]
+gpu = ["nvidia"]
 zfs = []
 
-# Including logging for debugging purposes.
+# Logging for debugging performance.
 logging = ["fern", "log", "time/local-offset"]
 
-# The features we use on deploy. Logging is not included as that is primarily (for now) just for debugging locally.
+default = ["battery", "gpu", "zfs"]
-deploy = ["battery", "gpu", "zfs"]
-
-default = ["deploy"]
 
 [dependencies]
 anyhow = "1.0.75"
 backtrace = "0.3.69"
 cfg-if = "1.0.0"
-clap = { version = "4.4.11", features = ["default", "cargo", "wrap_help"] }
+clap = { version = "4.4.14", features = ["default", "cargo", "wrap_help"] }
 concat-string = "1.0.1"
 crossterm = "0.27.0"
 ctrlc = { version = "3.4.1", features = ["termination"] }
@@ -93,7 +90,9 @@ indexmap = "2.1.0"
 itertools = "0.12.0"
 kstring = { version = "2.0.0", features = ["arc"] }
 log = { version = "0.4.20", optional = true }
-nvml-wrapper = { version = "0.9.0", optional = true, features = ["legacy-functions"] }
+nvml-wrapper = { version = "0.9.0", optional = true, features = [
+    "legacy-functions",
+] }
 regex = "1.10.2"
 serde = { version = "=1.0.193", features = ["derive"] }
 starship-battery = { version = "0.8.2", optional = true }
@@ -133,15 +132,17 @@ filedescriptor = "0.8.2"
 
 [dev-dependencies]
 assert_cmd = "2.0.12"
-cargo-husky = { version = "1.5.0", default-features = false, features = ["user-hooks"] }
+cargo-husky = { version = "1.5.0", default-features = false, features = [
+    "user-hooks",
+] }
 predicates = "3.0.3"
 
 [build-dependencies]
-clap = { version = "4.4.11", features = ["default", "cargo", "wrap_help"] }
+clap = { version = "4.4.14", features = ["default", "cargo", "wrap_help"] }
-clap_complete = "4.4.5"
+clap_complete = "4.4.6"
 clap_complete_fig = "4.4.2"
 clap_complete_nushell = "4.4.2"
-clap_mangen = "0.2.15"
+clap_mangen = "0.2.16"
 
 [package.metadata.deb]
 section = "utility"

build.rs

@@ -1,13 +1,18 @@
+#[allow(dead_code)]
+#[path = "src/options/args.rs"]
+mod args;
+
 use std::{
     env, fs, io,
     path::{Path, PathBuf},
 };
 
+use clap::Command;
 use clap_complete::{generate_to, shells::Shell, Generator};
 use clap_complete_fig::Fig;
 use clap_complete_nushell::Nushell;
 
-include!("src/options/args.rs");
+use crate::args::build_app;
 
 fn create_dir(dir: &Path) -> io::Result<()> {
     let res = fs::create_dir_all(dir);

src/options/args.rs

@@ -1,17 +1,10 @@
+//! Argument parsing via clap.
+//!
+//! Note that you probably want to keep this as a single file so the build script doesn't
+//! trip all over itself.
+
 use clap::{builder::PossibleValuesParser, *};
 
-const TEMPLATE: &str = "\
-{name} {version}
-{author}
-
-{about}
-
-{usage-heading} {usage}
-
-{all-args}";
-
-const USAGE: &str = "btm [OPTIONS]";
-
 const DEFAULT_WIDGET_TYPE_STR: &str = {
     #[cfg(feature = "battery")]
     {
@@ -87,30 +80,32 @@ pub fn get_matches() -> ArgMatches {
     build_app().get_matches()
 }
 
-pub fn build_app() -> Command {
+trait CommandBuilder {
-    // Temps
+    fn general_args(self) -> Self;
-    let kelvin = Arg::new("kelvin")
-        .short('k')
-        .long("kelvin")
-        .action(ArgAction::SetTrue)
-        .help("Sets the temperature type to Kelvin.")
-        .long_help("Sets the temperature type to Kelvin.");
 
-    let fahrenheit = Arg::new("fahrenheit")
+    fn style_args(self) -> Self;
-        .short('f')
-        .long("fahrenheit")
-        .action(ArgAction::SetTrue)
-        .help("Sets the temperature type to Fahrenheit.")
-        .long_help("Sets the temperature type to Fahrenheit.");
 
-    let celsius = Arg::new("celsius")
+    fn temperature_args(self) -> Self;
-        .short('c')
+
-        .long("celsius")
+    fn process_args(self) -> Self;
-        .action(ArgAction::SetTrue)
+
-        .help("Sets the temperature type to Celsius.")
+    fn cpu_args(self) -> Self;
-        .long_help("Sets the temperature type to Celsius. This is the default option.");
+
+    fn mem_args(self) -> Self;
+
+    fn network_args(self) -> Self;
+
+    fn battery_args(self) -> Self;
+
+    fn gpu_args(self) -> Self;
+
+    fn other(self) -> Self;
+}
+
+impl CommandBuilder for Command {
+    fn general_args(self) -> Command {
+        const HEADING: &str = "General Options";
 
-    // All flags. These are in alphabetical order
         let autohide_time = Arg::new("autohide_time")
             .long("autohide_time")
             .action(ArgAction::SetTrue)
@@ -119,7 +114,8 @@ pub fn build_app() -> Command {
                 "Automatically hides the time scale in graphs after being shown for \
             a brief moment when zoomed in/out. If time is disabled via --hide_time \
             then this will have no effect.",
-        );
+            )
+            .help_heading(HEADING);
 
         let basic = Arg::new("basic")
             .short('b')
@@ -128,121 +124,55 @@ pub fn build_app() -> Command {
             .help("Hides graphs and uses a more basic look.")
             .long_help(
                 "Hides graphs and uses a more basic look. Design is largely inspired by htop's.",
-        );
+            )
-
+            .help_heading(HEADING);
-    let case_sensitive = Arg::new("case_sensitive")
-        .short('S')
-        .long("case_sensitive")
-        .action(ArgAction::SetTrue)
-        .help("Enables case sensitivity by default.")
-        .long_help("When searching for a process, enables case sensitivity by default.");
-
-    let current_usage = Arg::new("current_usage")
-        .short('u')
-        .long("current_usage")
-        .action(ArgAction::SetTrue)
-        .help("Sets process CPU% to be based on current CPU%.")
-        .long_help("Sets process CPU% usage to be based on the current system CPU% usage rather than total CPU usage.");
-
-    let unnormalized_cpu = Arg::new("unnormalized_cpu")
-        .short('n')
-        .long("unnormalized_cpu")
-        .action(ArgAction::SetTrue)
-        .help("Show process CPU% usage without normalizing over the number of cores.")
-        .long_help(
-            "Shows all process CPU% usage without averaging over the number of CPU cores in the system.",
-        );
 
         let disable_click = Arg::new("disable_click")
             .long("disable_click")
             .action(ArgAction::SetTrue)
             .help("Disables mouse clicks.")
-        .long_help("Disables mouse clicks from interacting with the program.");
+            .long_help("Disables mouse clicks from interacting with the program.")
+            .help_heading(HEADING);
 
         let dot_marker = Arg::new("dot_marker")
             .short('m')
             .long("dot_marker")
             .action(ArgAction::SetTrue)
             .help("Uses a dot marker for graphs.")
-        .long_help("Uses a dot marker for graphs as opposed to the default braille marker.");
+            .long_help("Uses a dot marker for graphs as opposed to the default braille marker.")
-
+            .help_heading(HEADING);
-    let group_processes = Arg::new("group_processes")
-        .short('g')
-        .long("group_processes")
-        .action(ArgAction::SetTrue)
-        .help("Groups processes with the same name by default.")
-        .long_help("Groups processes with the same name by default.");
-
-    let hide_avg_cpu = Arg::new("hide_avg_cpu")
-        .short('a')
-        .long("hide_avg_cpu")
-        .action(ArgAction::SetTrue)
-        .help("Hides the average CPU usage.")
-        .long_help("Hides the average CPU usage from being shown.");
 
         let hide_table_gap = Arg::new("hide_table_gap")
             .long("hide_table_gap")
             .action(ArgAction::SetTrue)
             .help("Hides spacing between table headers and entries.")
-        .long_help("Hides the spacing between table headers and entries.");
+            .long_help("Hides the spacing between table headers and entries.")
+            .help_heading(HEADING);
 
         let hide_time = Arg::new("hide_time")
             .long("hide_time")
             .action(ArgAction::SetTrue)
             .help("Hides the time scale.")
-        .long_help("Completely hides the time scale from being shown.");
+            .long_help("Completely hides the time scale from being shown.")
-
+            .help_heading(HEADING);
-    let process_command = Arg::new("process_command")
-        .long("process_command")
-        .action(ArgAction::SetTrue)
-        .help("Show processes as their commands by default.")
-        .long_help("Show processes as their commands by default in the process widget.");
 
         let left_legend = Arg::new("left_legend")
             .short('l')
             .long("left_legend")
             .action(ArgAction::SetTrue)
             .help("Puts the CPU chart legend to the left side.")
-        .long_help("Puts the CPU chart legend to the left side rather than the right side.");
+            .long_help("Puts the CPU chart legend to the left side rather than the right side.")
-
+            .help_heading(HEADING);
-    let regex = Arg::new("regex")
-        .short('R')
-        .long("regex")
-        .action(ArgAction::SetTrue)
-        .help("Enables regex by default.")
-        .long_help("When searching for a process, enables regex by default.");
-
-    let disable_advanced_kill = Arg::new("disable_advanced_kill")
-        .long("disable_advanced_kill")
-        .action(ArgAction::SetTrue)
-        .help("Hides advanced process killing.")
-        .long_help("Hides advanced options to stop a process on Unix-like systems. The only option shown is 15 (TERM).");
 
         let show_table_scroll_position = Arg::new("show_table_scroll_position")
             .long("show_table_scroll_position")
             .action(ArgAction::SetTrue)
             .help("Shows the scroll position tracker in table widgets.")
-        .long_help("Shows the list scroll position tracker in the widget title for table widgets.");
-
-    let use_old_network_legend = Arg::new("use_old_network_legend")
-        .long("use_old_network_legend")
-        .action(ArgAction::SetTrue)
-        .help("DEPRECATED - uses a separate network legend.")
             .long_help(
-            "DEPRECATED - uses an older (pre-0.4), separate network widget legend. This display is not \
+                "Shows the list scroll position tracker in the widget title for table widgets.",
-            tested anymore and could be broken.",
+            )
-        );
+            .help_heading(HEADING);
 
-    let whole_word = Arg::new("whole_word")
-        .short('W')
-        .long("whole_word")
-        .action(ArgAction::SetTrue)
-        .help("Enables whole-word matching by default.")
-        .long_help(
-            "When searching for a process, return results that match the entire query by default.",
-        );
-
-    // All options. Again, alphabetical order.
         let config_location = Arg::new("config_location")
             .short('C')
             .long("config")
@@ -253,7 +183,115 @@ pub fn build_app() -> Command {
                 "Sets the location of the config file. Expects a config file in the TOML format. \
                 If it doesn't exist, one is created.",
             )
-        .value_hint(ValueHint::AnyPath);
+            .value_hint(ValueHint::AnyPath)
+            .help_heading(HEADING);
+
+        let default_time_value = Arg::new("default_time_value")
+            .short('t')
+            .long("default_time_value")
+            .action(ArgAction::Set)
+            .value_name("TIME")
+            .help("Default time value for graphs.")
+            .long_help(
+                "Default time value for graphs. Takes a number in milliseconds or a human duration (e.g. 60s). The minimum time is 30s, and the default is 60s.",
+            )
+            .help_heading(HEADING);
+
+        // TODO: Charts are broken in the manpage
+        let default_widget_count = Arg::new("default_widget_count")
+            .long("default_widget_count")
+            .action(ArgAction::Set)
+            .requires_all(["default_widget_type"])
+            .value_name("INT")
+            .help("Sets the n'th selected widget type as the default.")
+            .long_help(
+                "\
+Sets the n'th selected widget type to use as the default widget.
+Requires 'default_widget_type' to also be set, and defaults to 1.
+
+This reads from left to right, top to bottom. For example, suppose
+we have a layout that looks like:
++-------------------+-----------------------+
+|      CPU (1)      |        CPU (2)        |
++---------+---------+-------------+---------+
+| Process | CPU (3) | Temperature | CPU (4) |
++---------+---------+-------------+---------+
+
+And we set our default widget type to 'CPU'. If we set
+'--default_widget_count 1', then it would use the CPU (1) as
+the default widget. If we set '--default_widget_count 3', it would
+use CPU (3) as the default instead.
+    ",
+            )
+            .help_heading(HEADING);
+
+        let default_widget_type = Arg::new("default_widget_type")
+            .long("default_widget_type")
+            .action(ArgAction::Set)
+            .value_name("WIDGET TYPE")
+            .help("Sets the default widget type, use --help for info.")
+            .long_help(DEFAULT_WIDGET_TYPE_STR)
+            .help_heading(HEADING);
+
+        let expanded_on_startup = Arg::new("expanded_on_startup")
+            .short('e')
+            .long("expanded")
+            .action(ArgAction::SetTrue)
+            .help("Expand the default widget upon starting the app.")
+            .long_help("Expand the default widget upon starting the app. Same as pressing \"e\" inside the app. Use with \"default_widget_type\" and \"default_widget_count\" to select desired expanded widget. This flag has no effect in basic mode (--basic)")
+            .help_heading(HEADING);
+
+        let rate = Arg::new("rate")
+            .short('r')
+            .long("rate")
+            .action(ArgAction::Set)
+            .value_name("TIME")
+            .help("Sets the data refresh rate.")
+            .long_help("Sets the data refresh rate. Takes a number in milliseconds or a human duration (e.g. 5s). The minimum is 250ms, and defaults to 1000ms. Smaller values may take more computer resources.")
+            .help_heading(HEADING);
+
+        let time_delta = Arg::new("time_delta")
+            .short('d')
+            .long("time_delta")
+            .action(ArgAction::Set)
+            .value_name("TIME")
+            .help("The amount of time changed upon zooming.")
+            .long_help("The amount of time changed when zooming in/out. Takes a number in milliseconds or a human duration (e.g. 30s). The minimum is 1s, and defaults to 15s.")
+            .help_heading(HEADING);
+
+        let retention = Arg::new("retention")
+            .long("retention")
+            .action(ArgAction::Set)
+            .value_name("TIME")
+            .help("The timespan of data stored.")
+            .long_help("How much data is stored at once in terms of time. Takes a number in milliseconds or a human duration (e.g. 20m), with a minimum of 1 minute. Note higher values will take up more memory. Defaults to 10 minutes.")
+            .help_heading(HEADING);
+
+        let mut args = [
+            autohide_time,
+            basic,
+            disable_click,
+            dot_marker,
+            hide_table_gap,
+            hide_time,
+            left_legend,
+            show_table_scroll_position,
+            config_location,
+            default_time_value,
+            default_widget_count,
+            default_widget_type,
+            expanded_on_startup,
+            rate,
+            time_delta,
+            retention,
+        ];
+        args.sort_unstable();
+
+        self.args(args)
+    }
+
+    fn style_args(self) -> Command {
+        const HEADING: &str = "Style Options";
 
         // TODO: File an issue with manpage, it cannot render charts correctly.
         let color = Arg::new("color")
@@ -288,99 +326,207 @@ Use a pre-defined color scheme. Currently supported values are:
 +------------------------------------------------------------+
 Defaults to \"default\".
     ",
-        );
+            )
+            .help_heading(HEADING);
 
-    let mem_as_value = Arg::new("mem_as_value")
+        self.arg(color)
-        .long("mem_as_value")
+    }
+
+    fn temperature_args(self) -> Command {
+        const HEADING: &str = "Temperature Options";
+
+        let celsius = Arg::new("celsius")
+            .short('c')
+            .long("celsius")
             .action(ArgAction::SetTrue)
-        .help("Defaults to showing process memory usage by value.")
+            .help("Use Celsius as the temperature unit.")
-        .long_help("Defaults to showing process memory usage by value. Otherwise, it defaults to showing it by percentage.");
+            .long_help("Use Celsius as the temperature unit. This is the default option.")
+            .help_heading(HEADING);
 
-    let default_time_value = Arg::new("default_time_value")
+        let fahrenheit = Arg::new("fahrenheit")
-        .short('t')
+            .short('f')
-        .long("default_time_value")
+            .long("fahrenheit")
-        .action(ArgAction::Set)
-        .value_name("TIME")
-        .help("Default time value for graphs.")
-        .long_help(
-            "Default time value for graphs. Takes a number in milliseconds or a human duration (e.g. 60s). The minimum time is 30s, and the default is 60s.",
-        );
-
-    // TODO: Charts are broken in the manpage
-    let default_widget_count = Arg::new("default_widget_count")
-        .long("default_widget_count")
-        .action(ArgAction::Set)
-        .requires_all(["default_widget_type"])
-        .value_name("INT")
-        .help("Sets the n'th selected widget type as the default.")
-        .long_help(
-            "\
-Sets the n'th selected widget type to use as the default widget.
-Requires 'default_widget_type' to also be set, and defaults to 1.
-
-This reads from left to right, top to bottom. For example, suppose
-we have a layout that looks like:
-+-------------------+-----------------------+
-|      CPU (1)      |        CPU (2)        |
-+---------+---------+-------------+---------+
-| Process | CPU (3) | Temperature | CPU (4) |
-+---------+---------+-------------+---------+
-
-And we set our default widget type to 'CPU'. If we set
-'--default_widget_count 1', then it would use the CPU (1) as
-the default widget. If we set '--default_widget_count 3', it would
-use CPU (3) as the default instead.
-",
-        );
-
-    let default_widget_type = Arg::new("default_widget_type")
-        .long("default_widget_type")
-        .action(ArgAction::Set)
-        .value_name("WIDGET TYPE")
-        .help("Sets the default widget type, use --help for info.")
-        .long_help(DEFAULT_WIDGET_TYPE_STR);
-
-    let expanded_on_startup = Arg::new("expanded_on_startup")
-        .short('e')
-        .long("expanded")
             .action(ArgAction::SetTrue)
-        .help("Expand the default widget upon starting the app.")
+            .help("Use Fahrenheit as the temperature unit.")
-        .long_help("Expand the default widget upon starting the app. Same as pressing \"e\" inside the app. Use with \"default_widget_type\" and \"default_widget_count\" to select desired expanded widget. This flag has no effect in basic mode (--basic)");
+            .help_heading(HEADING);
 
-    let rate = Arg::new("rate")
+        let kelvin = Arg::new("kelvin")
-        .short('r')
+            .short('k')
-        .long("rate")
+            .long("kelvin")
-        .action(ArgAction::Set)
+            .action(ArgAction::SetTrue)
-        .value_name("TIME")
+            .help("Use Kelvin as the temperature unit.")
-        .help("Sets the data refresh rate.")
+            .help_heading(HEADING);
-        .long_help("Sets the data refresh rate. Takes a number in milliseconds or a human duration (e.g. 5s). The minimum is 250ms, and defaults to 1000ms. Smaller values may take more computer resources.");
 
-    let time_delta = Arg::new("time_delta")
+        let temperature_group = ArgGroup::new("TEMPERATURE_TYPE").args([
-        .short('d')
+            celsius.get_id(),
-        .long("time_delta")
+            fahrenheit.get_id(),
-        .action(ArgAction::Set)
+            kelvin.get_id(),
-        .value_name("TIME")
+        ]);
-        .help("The amount of time changed upon zooming.")
+
-        .long_help("The amount of time changed when zooming in/out. Takes a number in milliseconds or a human duration (e.g. 30s). The minimum is 1s, and defaults to 15s.");
+        let args = [celsius, fahrenheit, kelvin];
+
+        self.args(args).group(temperature_group)
+    }
+
+    fn process_args(self) -> Command {
+        const HEADING: &str = "Process Options";
+
+        let case_sensitive = Arg::new("case_sensitive")
+            .short('S')
+            .long("case_sensitive")
+            .action(ArgAction::SetTrue)
+            .help("Enables case sensitivity by default.")
+            .long_help("When searching for a process, enables case sensitivity by default.")
+            .help_heading(HEADING);
+
+        let current_usage = Arg::new("current_usage")
+            .short('u')
+            .long("current_usage")
+            .action(ArgAction::SetTrue)
+            .help("Sets process CPU% to be based on current CPU%.")
+            .long_help("Sets process CPU% usage to be based on the current system CPU% usage rather than total CPU usage.")
+            .help_heading(HEADING);
+
+        let unnormalized_cpu = Arg::new("unnormalized_cpu")
+            .short('n')
+            .long("unnormalized_cpu")
+            .action(ArgAction::SetTrue)
+            .help("Show process CPU% usage without normalizing over the number of cores.")
+            .long_help(
+                "Shows all process CPU% usage without averaging over the number of CPU cores in the system.",
+            )
+            .help_heading(HEADING);
+
+        let group_processes = Arg::new("group_processes")
+            .short('g')
+            .long("group_processes")
+            .action(ArgAction::SetTrue)
+            .help("Groups processes with the same name by default.")
+            .long_help("Groups processes with the same name by default.")
+            .help_heading(HEADING);
+
+        let process_command = Arg::new("process_command")
+            .long("process_command")
+            .action(ArgAction::SetTrue)
+            .help("Show processes as their commands by default.")
+            .long_help("Show processes as their commands by default in the process widget.")
+            .help_heading(HEADING);
+
+        let regex = Arg::new("regex")
+            .short('R')
+            .long("regex")
+            .action(ArgAction::SetTrue)
+            .help("Enables regex by default.")
+            .long_help("When searching for a process, enables regex by default.")
+            .help_heading(HEADING);
+
+        let disable_advanced_kill = Arg::new("disable_advanced_kill")
+            .long("disable_advanced_kill")
+            .action(ArgAction::SetTrue)
+            .help("Hides advanced process killing.")
+            .long_help("Hides advanced options to stop a process on Unix-like systems. The only option shown is 15 (TERM).")
+            .help_heading(HEADING);
+
+        let whole_word = Arg::new("whole_word")
+            .short('W')
+            .long("whole_word")
+            .action(ArgAction::SetTrue)
+            .help("Enables whole-word matching by default.")
+            .long_help(
+                "When searching for a process, return results that match the entire query by default.",
+            )
+            .help_heading(HEADING);
 
         let tree = Arg::new("tree")
             .short('T')
             .long("tree")
             .action(ArgAction::SetTrue)
             .help("Defaults the process widget be in tree mode.")
-        .long_help("Defaults to showing the process widget in tree mode.");
+            .long_help("Defaults to showing the process widget in tree mode.")
+            .help_heading(HEADING);
+
+        let mut args = [
+            case_sensitive,
+            current_usage,
+            unnormalized_cpu,
+            group_processes,
+            process_command,
+            regex,
+            whole_word,
+            disable_advanced_kill,
+            tree,
+        ];
+        args.sort_unstable();
+
+        self.args(args)
+    }
+
+    fn cpu_args(self) -> Command {
+        const HEADING: &str = "CPU Options";
+
+        let hide_avg_cpu = Arg::new("hide_avg_cpu")
+            .short('a')
+            .long("hide_avg_cpu")
+            .action(ArgAction::SetTrue)
+            .help("Hides the average CPU usage.")
+            .long_help("Hides the average CPU usage from being shown.")
+            .help_heading(HEADING);
+
+        self.arg(hide_avg_cpu)
+    }
+
+    fn mem_args(self) -> Command {
+        const HEADING: &str = "Memory Options";
+
+        let mem_as_value = Arg::new("mem_as_value")
+            .long("mem_as_value")
+            .action(ArgAction::SetTrue)
+            .help("Defaults to showing process memory usage by value.")
+            .long_help("Defaults to showing process memory usage by value. Otherwise, it defaults to showing it by percentage.")
+            .help_heading(HEADING);
+
+        #[cfg(not(target_os = "windows"))]
+        {
+            let enable_cache_memory = Arg::new("enable_cache_memory")
+                .long("enable_cache_memory")
+                .action(ArgAction::SetTrue)
+                .help("Enable collecting and displaying cache and buffer memory.")
+                .help_heading(HEADING);
+
+            self.args([mem_as_value, enable_cache_memory])
+        }
+        #[cfg(target_os = "windows")]
+        {
+            self.arg(mem_as_value)
+        }
+    }
+
+    fn network_args(self) -> Command {
+        const HEADING: &str = "Network Options";
+
+        let use_old_network_legend = Arg::new("use_old_network_legend")
+            .long("use_old_network_legend")
+            .action(ArgAction::SetTrue)
+            .help("DEPRECATED - uses a separate network legend.")
+            .long_help(
+                "DEPRECATED - uses an older (pre-0.4), separate network widget legend. This display is not \
+                tested anymore and could be broken.",
+            )
+            .help_heading(HEADING);
 
         let network_use_bytes = Arg::new("network_use_bytes")
             .long("network_use_bytes")
             .action(ArgAction::SetTrue)
             .help("Displays the network widget using bytes.")
-        .long_help("Displays the network widget using bytes. Defaults to bits.");
+            .long_help("Displays the network widget using bytes. Defaults to bits.")
+            .help_heading(HEADING);
 
         let network_use_log = Arg::new("network_use_log")
             .long("network_use_log")
             .action(ArgAction::SetTrue)
             .help("Displays the network widget with a log scale.")
-        .long_help("Displays the network widget with a log scale. Defaults to a non-log scale.");
+            .long_help("Displays the network widget with a log scale. Defaults to a non-log scale.")
+            .help_heading(HEADING);
 
         let network_use_binary_prefix = Arg::new("network_use_binary_prefix")
             .long("network_use_binary_prefix")
@@ -388,113 +534,106 @@ use CPU (3) as the default instead.
             .help("Displays the network widget with binary prefixes.")
             .long_help(
                 "Displays the network widget with binary prefixes (i.e. kibibits, mebibits) rather than a decimal prefix (i.e. kilobits, megabits). Defaults to decimal prefixes.",
-        );
+            )
-
+            .help_heading(HEADING);
-    let retention = Arg::new("retention")
-        .long("retention")
-        .action(ArgAction::Set)
-        .value_name("TIME")
-        .help("The timespan of data stored.")
-        .long_help("How much data is stored at once in terms of time. Takes a number in milliseconds or a human duration (e.g. 20m), with a minimum of 1 minute. Note higher values will take up more memory. Defaults to 10 minutes.");
-
-    let version = Arg::new("version")
-        .short('V')
-        .long("version")
-        .action(ArgAction::Version)
-        .help("Prints version information.");
-
-    const VERSION: &str = match option_env!("NIGHTLY_VERSION") {
-        Some(nightly_version) => nightly_version,
-        None => crate_version!(),
-    };
-
-    let temperature_group = ArgGroup::new("TEMPERATURE_TYPE").args([
-        kelvin.get_id(),
-        fahrenheit.get_id(),
-        celsius.get_id(),
-    ]);
 
         let mut args = [
-        version,
+            use_old_network_legend,
-        kelvin,
-        fahrenheit,
-        celsius,
-        autohide_time,
-        basic,
-        case_sensitive,
-        process_command,
-        config_location,
-        color,
-        mem_as_value,
-        default_time_value,
-        default_widget_count,
-        default_widget_type,
-        disable_click,
-        dot_marker,
-        group_processes,
-        hide_avg_cpu,
-        hide_table_gap,
-        hide_time,
-        show_table_scroll_position,
-        left_legend,
-        disable_advanced_kill,
-        rate,
-        regex,
-        time_delta,
-        tree,
             network_use_bytes,
             network_use_log,
             network_use_binary_prefix,
-        current_usage,
+        ];
-        unnormalized_cpu,
+
-        use_old_network_legend,
+        args.sort_unstable();
-        whole_word,
+
-        retention,
+        self.args(args)
-        expanded_on_startup,
+    }
+
+    fn battery_args(self) -> Command {
         #[cfg(feature = "battery")]
         {
-            Arg::new("battery")
+            let battery = Arg::new("battery")
             .long("battery")
             .action(ArgAction::SetTrue)
             .help("Shows the battery widget.")
             .long_help(
                 "Shows the battery widget in default or basic mode. No effect on custom layouts.",
             )
-        },
+            .help_heading("Battery Options");
+
+            self.arg(battery)
+        }
+        #[cfg(not(feature = "battery"))]
+        {
+            self
+        }
+    }
+
+    fn gpu_args(self) -> Command {
         #[cfg(feature = "gpu")]
         {
-            Arg::new("enable_gpu")
+            let enable_gpu = Arg::new("enable_gpu")
                 .long("enable_gpu")
                 .action(ArgAction::SetTrue)
                 .help("Enable collecting and displaying GPU usage.")
-        },
+                .help_heading("GPU Options");
-        #[cfg(not(target_os = "windows"))]
+
+            self.arg(enable_gpu)
+        }
+        #[cfg(not(feature = "gpu"))]
         {
-            Arg::new("enable_cache_memory")
+            self
-                .long("enable_cache_memory")
+        }
-                .action(ArgAction::SetTrue)
+    }
-                .help("Enable collecting and displaying cache and buffer memory.")
-        },
-    ];
 
-    // Manually sort the arguments.
+    fn other(self) -> Command {
-    args.sort_by(|a, b| {
+        const HEADING: &str = "Other Options";
-        let a = a.get_long().unwrap_or(a.get_id().as_str());
-        let b = b.get_long().unwrap_or(b.get_id().as_str());
 
-        a.cmp(b)
+        let version = Arg::new("version")
-    });
+            .short('V')
+            .long("version")
+            .action(ArgAction::Version)
+            .help("Prints version information.")
+            .help_heading(HEADING);
+
+        let help = Arg::new("help")
+            .short('h')
+            .long("help")
+            .action(ArgAction::Help)
+            .help("Prints help (see more with '--help').")
+            .help_heading(HEADING);
+
+        self.args([version, help])
+    }
+}
+
+pub fn build_app() -> Command {
+    const TEMPLATE: &str = include_str!("./args.template");
+    const USAGE: &str = "btm [OPTIONS]";
+    const VERSION: &str = match option_env!("NIGHTLY_VERSION") {
+        Some(nightly_version) => nightly_version,
+        None => crate_version!(),
+    };
 
     Command::new(crate_name!())
-        .version(VERSION)
         .author(crate_authors!())
         .about(crate_description!())
-        .color(ColorChoice::Auto)
+        .disable_help_flag(true)
-        .override_usage(USAGE)
-        .help_template(TEMPLATE)
         .disable_version_flag(true)
-        .args(args)
+        .color(ColorChoice::Auto)
-        .group(temperature_group)
+        .help_template(TEMPLATE)
+        .override_usage(USAGE)
+        .version(VERSION)
+        .general_args()
+        .style_args()
+        .temperature_args()
+        .process_args()
+        .cpu_args()
+        .mem_args()
+        .network_args()
+        .battery_args()
+        .gpu_args()
+        .other()
 }
 
 #[cfg(test)]
@@ -505,4 +644,15 @@ mod test {
     fn verify_cli() {
         build_app().debug_assert();
     }
+
+    #[test]
+    fn help_heading_no_default() {
+        let mut app = build_app();
+        let help_str = app.render_help();
+
+        assert!(
+            !help_str.to_string().contains("\nOptions:\n"),
+            "the default 'Options' heading should not exist; if it does then an argument is missing a help heading."
+        );
+    }
 }

src/options/args.template

@@ -0,0 +1,8 @@
+{name} {version}
+{author}
+
+{about}
+
+{usage-heading} {usage}
+
+{all-args}