Struct clap::ArgMatches
source · [−]pub struct ArgMatches { /* private fields */ }
Expand description
Container for parse results.
Used to get information about the arguments that were supplied to the program at runtime by
the user. New instances of this struct are obtained by using the Command::get_matches
family of
methods.
Examples
let matches = Command::new("MyApp")
.arg(Arg::new("out")
.long("output")
.required(true)
.takes_value(true))
.arg(Arg::new("debug")
.short('d')
.multiple_occurrences(true))
.arg(Arg::new("cfg")
.short('c')
.takes_value(true))
.get_matches(); // builds the instance of ArgMatches
// to get information about the "cfg" argument we created, such as the value supplied we use
// various ArgMatches methods, such as ArgMatches::value_of
if let Some(c) = matches.value_of("cfg") {
println!("Value for -c: {}", c);
}
// The ArgMatches::value_of method returns an Option because the user may not have supplied
// that argument at runtime. But if we specified that the argument was "required" as we did
// with the "out" argument, we can safely unwrap because `clap` verifies that was actually
// used at runtime.
println!("Value for --output: {}", matches.value_of("out").unwrap());
// You can check the presence of an argument
if matches.is_present("out") {
// Another way to check if an argument was present, or if it occurred multiple times is to
// use occurrences_of() which returns 0 if an argument isn't found at runtime, or the
// number of times that it occurred, if it was. To allow an argument to appear more than
// once, you must use the .multiple_occurrences(true) method, otherwise it will only return 1 or 0.
if matches.occurrences_of("debug") > 2 {
println!("Debug mode is REALLY on, don't be crazy");
} else {
println!("Debug mode kind of on");
}
}
Implementations
sourceimpl ArgMatches
impl ArgMatches
sourcepub fn args_present(&self) -> bool
pub fn args_present(&self) -> bool
Check if any args were present on the command line
Examples
let mut cmd = Command::new("myapp")
.arg(Arg::new("output")
.takes_value(true));
let m = cmd
.try_get_matches_from_mut(vec!["myapp", "something"])
.unwrap();
assert!(m.args_present());
let m = cmd
.try_get_matches_from_mut(vec!["myapp"])
.unwrap();
assert!(! m.args_present());
sourcepub fn value_of<T: Key>(&self, id: T) -> Option<&str>
pub fn value_of<T: Key>(&self, id: T) -> Option<&str>
Gets the value of a specific option or positional argument.
i.e. an argument that takes an additional value at runtime.
Returns None
if the option wasn’t present.
NOTE: Prefer ArgMatches::values_of
if getting a value for an option or positional
argument that allows multiples as ArgMatches::value_of
will only return the first
value.
NOTE: This will always return Some(value)
if default_value
has been set.
occurrences_of
can be used to check if a value is present at runtime.
Panics
If the value is invalid UTF-8. See
Arg::allow_invalid_utf8
.
If id
is is not a valid argument or group name.
Examples
let m = Command::new("myapp")
.arg(Arg::new("output")
.takes_value(true))
.get_matches_from(vec!["myapp", "something"]);
assert_eq!(m.value_of("output"), Some("something"));
Examples found in repository?
More examples
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fn from_arg_matches(matches: &ArgMatches) -> Result<Self, Error> {
Ok(Self {
foo: matches.is_present("foo"),
bar: matches.is_present("bar"),
quuz: matches.value_of("quuz").map(|quuz| quuz.to_owned()),
})
}
fn update_from_arg_matches(&mut self, matches: &ArgMatches) -> Result<(), Error> {
self.foo |= matches.is_present("foo");
self.bar |= matches.is_present("bar");
if let Some(quuz) = matches.value_of("quuz") {
self.quuz = Some(quuz.to_owned());
}
Ok(())
}
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fn main() {
let matches = command!()
.arg(arg!([NAME]).default_value("alice"))
.get_matches();
println!(
"NAME: {:?}",
matches
.value_of("NAME")
.expect("default ensures there is always a value")
);
}
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fn main() {
let matches = Command::new("MyApp")
.version("1.0")
.author("Kevin K. <kbknapp@gmail.com>")
.about("Does awesome things")
.arg(arg!(--two <VALUE>))
.arg(arg!(--one <VALUE>))
.get_matches();
println!("two: {:?}", matches.value_of("two").expect("required"));
println!("one: {:?}", matches.value_of("one").expect("required"));
}
- examples/tutorial_builder/02_app_settings.rs
- examples/tutorial_builder/04_01_possible.rs
- examples/tutorial_builder/03_04_subcommands.rs
- examples/escaped-positional.rs
- examples/tutorial_builder/01_quick.rs
- examples/git.rs
- examples/tutorial_builder/04_03_relations.rs
- examples/tutorial_builder/04_04_custom.rs
sourcepub fn value_of_lossy<T: Key>(&self, id: T) -> Option<Cow<'_, str>>
pub fn value_of_lossy<T: Key>(&self, id: T) -> Option<Cow<'_, str>>
Gets the lossy value of a specific option or positional argument.
i.e. an argument that takes an additional value at runtime.
A lossy value is one which contains invalid UTF-8, those invalid points will be replaced
with \u{FFFD}
Returns None
if the option wasn’t present.
NOTE: Recommend having set Arg::allow_invalid_utf8
.
NOTE: Prefer ArgMatches::values_of_lossy
if getting a value for an option or positional
argument that allows multiples as ArgMatches::value_of_lossy
will only return the first
value.
NOTE: This will always return Some(value)
if default_value
has been set.
occurrences_of
can be used to check if a value is present at runtime.
Panics
If id
is is not a valid argument or group name.
Examples
use std::ffi::OsString;
use std::os::unix::ffi::{OsStrExt,OsStringExt};
let m = Command::new("utf8")
.arg(arg!(<arg> "some arg")
.allow_invalid_utf8(true))
.get_matches_from(vec![OsString::from("myprog"),
// "Hi {0xe9}!"
OsString::from_vec(vec![b'H', b'i', b' ', 0xe9, b'!'])]);
assert_eq!(&*m.value_of_lossy("arg").unwrap(), "Hi \u{FFFD}!");
sourcepub fn value_of_os<T: Key>(&self, id: T) -> Option<&OsStr>
pub fn value_of_os<T: Key>(&self, id: T) -> Option<&OsStr>
Get the OsStr
value of a specific option or positional argument.
i.e. an argument that takes an additional value at runtime.
An OsStr
on Unix-like systems is any series of bytes, regardless of whether or not they
contain valid UTF-8. Since String
s in Rust are guaranteed to be valid UTF-8, a valid
filename on a Unix system as an argument value may contain invalid UTF-8.
Returns None
if the option wasn’t present.
NOTE: Recommend having set Arg::allow_invalid_utf8
.
NOTE: Prefer ArgMatches::values_of_os
if getting a value for an option or positional
argument that allows multiples as ArgMatches::value_of_os
will only return the first
value.
NOTE: This will always return Some(value)
if default_value
has been set.
occurrences_of
can be used to check if a value is present at runtime.
Panics
If id
is is not a valid argument or group name.
Examples
use std::ffi::OsString;
use std::os::unix::ffi::{OsStrExt,OsStringExt};
let m = Command::new("utf8")
.arg(arg!(<arg> "some arg")
.allow_invalid_utf8(true))
.get_matches_from(vec![OsString::from("myprog"),
// "Hi {0xe9}!"
OsString::from_vec(vec![b'H', b'i', b' ', 0xe9, b'!'])]);
assert_eq!(&*m.value_of_os("arg").unwrap().as_bytes(), [b'H', b'i', b' ', 0xe9, b'!']);
Examples found in repository?
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fn main() {
let cmd = clap::Command::new("cargo")
.bin_name("cargo")
.subcommand_required(true)
.subcommand(
clap::command!("example").arg(
clap::arg!(--"manifest-path" <PATH>)
.required(false)
.allow_invalid_utf8(true),
),
);
let matches = cmd.get_matches();
let matches = match matches.subcommand() {
Some(("example", matches)) => matches,
_ => unreachable!("clap should ensure we don't get here"),
};
let manifest_path = matches
.value_of_os("manifest-path")
.map(std::path::PathBuf::from);
println!("{:?}", manifest_path);
}
More examples
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fn main() {
let matches = command!()
.arg(arg!([name] "Optional name to operate on"))
.arg(
arg!(
-c --config <FILE> "Sets a custom config file"
)
// We don't have syntax yet for optional options, so manually calling `required`
.required(false)
// Support non-UTF8 paths
.allow_invalid_utf8(true),
)
.arg(arg!(
-d --debug ... "Turn debugging information on"
))
.subcommand(
Command::new("test")
.about("does testing things")
.arg(arg!(-l --list "lists test values")),
)
.get_matches();
// You can check the value provided by positional arguments, or option arguments
if let Some(name) = matches.value_of("name") {
println!("Value for name: {}", name);
}
if let Some(raw_config) = matches.value_of_os("config") {
let config_path = Path::new(raw_config);
println!("Value for config: {}", config_path.display());
}
// You can see how many times a particular flag or argument occurred
// Note, only flags can have multiple occurrences
match matches.occurrences_of("debug") {
0 => println!("Debug mode is off"),
1 => println!("Debug mode is kind of on"),
2 => println!("Debug mode is on"),
_ => println!("Don't be crazy"),
}
// You can check for the existence of subcommands, and if found use their
// matches just as you would the top level cmd
if let Some(matches) = matches.subcommand_matches("test") {
// "$ myapp test" was run
if matches.is_present("list") {
// "$ myapp test -l" was run
println!("Printing testing lists...");
} else {
println!("Not printing testing lists...");
}
}
// Continued program logic goes here...
}
sourcepub fn values_of<T: Key>(&self, id: T) -> Option<Values<'_>>
pub fn values_of<T: Key>(&self, id: T) -> Option<Values<'_>>
Get an Iterator
over values of a specific option or positional argument.
i.e. an argument that takes multiple values at runtime.
Returns None
if the option wasn’t present.
Panics
If the value is invalid UTF-8. See
Arg::allow_invalid_utf8
.
If id
is is not a valid argument or group name.
Examples
let m = Command::new("myprog")
.arg(Arg::new("output")
.multiple_occurrences(true)
.short('o')
.takes_value(true))
.get_matches_from(vec![
"myprog", "-o", "val1", "-o", "val2", "-o", "val3"
]);
let vals: Vec<&str> = m.values_of("output").unwrap().collect();
assert_eq!(vals, ["val1", "val2", "val3"]);
Examples found in repository?
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fn main() {
let matches = command!()
.arg(arg!(eff: -f))
.arg(arg!(pea: -p <PEAR>).required(false))
.arg(
arg!(slop: [SLOP]).multiple_occurrences(true).last(true), // Indicates that `slop` is only accessible after `--`.
)
.get_matches();
// This is what will happen with `myprog -f -p=bob -- sloppy slop slop`...
println!("-f used: {:?}", matches.is_present("eff")); // -f used: true
println!("-p's value: {:?}", matches.value_of("pea")); // -p's value: Some("bob")
println!(
"'slops' values: {:?}",
matches
.values_of("slop")
.map(|vals| vals.collect::<Vec<_>>())
.unwrap_or_default()
); // 'slops' values: Some(["sloppy", "slop", "slop"])
// Continued program logic goes here...
}
More examples
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fn main() {
let matches = Command::new("pacman")
.about("package manager utility")
.version("5.2.1")
.subcommand_required(true)
.arg_required_else_help(true)
.author("Pacman Development Team")
// Query subcommand
//
// Only a few of its arguments are implemented below.
.subcommand(
Command::new("query")
.short_flag('Q')
.long_flag("query")
.about("Query the package database.")
.arg(
Arg::new("search")
.short('s')
.long("search")
.help("search locally installed packages for matching strings")
.conflicts_with("info")
.takes_value(true)
.multiple_values(true),
)
.arg(
Arg::new("info")
.long("info")
.short('i')
.conflicts_with("search")
.help("view package information")
.takes_value(true)
.multiple_values(true),
),
)
// Sync subcommand
//
// Only a few of its arguments are implemented below.
.subcommand(
Command::new("sync")
.short_flag('S')
.long_flag("sync")
.about("Synchronize packages.")
.arg(
Arg::new("search")
.short('s')
.long("search")
.conflicts_with("info")
.takes_value(true)
.multiple_values(true)
.help("search remote repositories for matching strings"),
)
.arg(
Arg::new("info")
.long("info")
.conflicts_with("search")
.short('i')
.help("view package information"),
)
.arg(
Arg::new("package")
.help("packages")
.required_unless_present("search")
.takes_value(true)
.multiple_values(true),
),
)
.get_matches();
match matches.subcommand() {
Some(("sync", sync_matches)) => {
if sync_matches.is_present("search") {
let packages: Vec<_> = sync_matches.values_of("search").unwrap().collect();
let values = packages.join(", ");
println!("Searching for {}...", values);
return;
}
let packages: Vec<_> = sync_matches.values_of("package").unwrap().collect();
let values = packages.join(", ");
if sync_matches.is_present("info") {
println!("Retrieving info for {}...", values);
} else {
println!("Installing {}...", values);
}
}
Some(("query", query_matches)) => {
if let Some(packages) = query_matches.values_of("info") {
let comma_sep = packages.collect::<Vec<_>>().join(", ");
println!("Retrieving info for {}...", comma_sep);
} else if let Some(queries) = query_matches.values_of("search") {
let comma_sep = queries.collect::<Vec<_>>().join(", ");
println!("Searching Locally for {}...", comma_sep);
} else {
println!("Displaying all locally installed packages...");
}
}
_ => unreachable!(), // If all subcommands are defined above, anything else is unreachable
}
}
sourcepub fn grouped_values_of<T: Key>(&self, id: T) -> Option<GroupedValues<'_>>
Available on crate feature unstable-grouped
only.
pub fn grouped_values_of<T: Key>(&self, id: T) -> Option<GroupedValues<'_>>
unstable-grouped
only.Get an Iterator
over groups of values of a specific option.
specifically grouped by the occurrences of the options.
Each group is a Vec<&str>
containing the arguments passed to a single occurrence
of the option.
If the option doesn’t support multiple occurrences, or there was only a single occurrence, the iterator will only contain a single item.
Returns None
if the option wasn’t present.
Panics
If the value is invalid UTF-8.
If id
is not a valid argument or group name.
Examples
let m = Command::new("myprog")
.arg(Arg::new("exec")
.short('x')
.min_values(1)
.multiple_occurrences(true)
.value_terminator(";"))
.get_matches_from(vec![
"myprog", "-x", "echo", "hi", ";", "-x", "echo", "bye"]);
let vals: Vec<Vec<&str>> = m.grouped_values_of("exec").unwrap().collect();
assert_eq!(vals, [["echo", "hi"], ["echo", "bye"]]);
sourcepub fn values_of_lossy<T: Key>(&self, id: T) -> Option<Vec<String>>
pub fn values_of_lossy<T: Key>(&self, id: T) -> Option<Vec<String>>
Get the lossy values of a specific option or positional argument.
i.e. an argument that takes multiple values at runtime.
A lossy value is one which contains invalid UTF-8, those invalid points will be replaced
with \u{FFFD}
Returns None
if the option wasn’t present.
NOTE: Recommend having set Arg::allow_invalid_utf8
.
Panics
If id
is is not a valid argument or group name.
Examples
use std::ffi::OsString;
use std::os::unix::ffi::OsStringExt;
let m = Command::new("utf8")
.arg(arg!(<arg> ... "some arg")
.allow_invalid_utf8(true))
.get_matches_from(vec![OsString::from("myprog"),
// "Hi"
OsString::from_vec(vec![b'H', b'i']),
// "{0xe9}!"
OsString::from_vec(vec![0xe9, b'!'])]);
let mut itr = m.values_of_lossy("arg").unwrap().into_iter();
assert_eq!(&itr.next().unwrap()[..], "Hi");
assert_eq!(&itr.next().unwrap()[..], "\u{FFFD}!");
assert_eq!(itr.next(), None);
sourcepub fn values_of_os<T: Key>(&self, id: T) -> Option<OsValues<'_>>
pub fn values_of_os<T: Key>(&self, id: T) -> Option<OsValues<'_>>
Get an Iterator
over OsStr
values of a specific option or positional argument.
i.e. an argument that takes multiple values at runtime.
An OsStr
on Unix-like systems is any series of bytes, regardless of whether or not they
contain valid UTF-8. Since String
s in Rust are guaranteed to be valid UTF-8, a valid
filename on a Unix system as an argument value may contain invalid UTF-8.
Returns None
if the option wasn’t present.
NOTE: Recommend having set Arg::allow_invalid_utf8
.
Panics
If id
is is not a valid argument or group name.
Examples
use std::ffi::{OsStr,OsString};
use std::os::unix::ffi::{OsStrExt,OsStringExt};
let m = Command::new("utf8")
.arg(arg!(<arg> ... "some arg")
.allow_invalid_utf8(true))
.get_matches_from(vec![OsString::from("myprog"),
// "Hi"
OsString::from_vec(vec![b'H', b'i']),
// "{0xe9}!"
OsString::from_vec(vec![0xe9, b'!'])]);
let mut itr = m.values_of_os("arg").unwrap().into_iter();
assert_eq!(itr.next(), Some(OsStr::new("Hi")));
assert_eq!(itr.next(), Some(OsStr::from_bytes(&[0xe9, b'!'])));
assert_eq!(itr.next(), None);
Examples found in repository?
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fn main() {
let matches = cli().get_matches();
match matches.subcommand() {
Some(("clone", sub_matches)) => {
println!(
"Cloning {}",
sub_matches.value_of("REMOTE").expect("required")
);
}
Some(("push", sub_matches)) => {
println!(
"Pushing to {}",
sub_matches.value_of("REMOTE").expect("required")
);
}
Some(("add", sub_matches)) => {
let paths = sub_matches
.values_of_os("PATH")
.unwrap_or_default()
.map(PathBuf::from)
.collect::<Vec<_>>();
println!("Adding {:?}", paths);
}
Some(("stash", sub_matches)) => {
let stash_command = sub_matches.subcommand().unwrap_or(("push", sub_matches));
match stash_command {
("apply", sub_matches) => {
let stash = sub_matches.value_of("STASH");
println!("Applying {:?}", stash);
}
("pop", sub_matches) => {
let stash = sub_matches.value_of("STASH");
println!("Popping {:?}", stash);
}
("push", sub_matches) => {
let message = sub_matches.value_of("message");
println!("Pushing {:?}", message);
}
(name, _) => {
unreachable!("Unsupported subcommand `{}`", name)
}
}
}
Some((ext, sub_matches)) => {
let args = sub_matches
.values_of_os("")
.unwrap_or_default()
.collect::<Vec<_>>();
println!("Calling out to {:?} with {:?}", ext, args);
}
_ => unreachable!(), // If all subcommands are defined above, anything else is unreachabe!()
}
// Continued program logic goes here...
}
sourcepub fn value_of_t<R>(&self, name: &str) -> Result<R, Error> where
R: FromStr,
<R as FromStr>::Err: Display,
pub fn value_of_t<R>(&self, name: &str) -> Result<R, Error> where
R: FromStr,
<R as FromStr>::Err: Display,
Parse the value (with FromStr
) of a specific option or positional argument.
There are two types of errors, parse failures and those where the argument wasn’t present
(such as a non-required argument). Check ErrorKind
to distinguish them.
NOTE: If getting a value for an option or positional argument that allows multiples,
prefer ArgMatches::values_of_t
as this method will only return the first
value.
Panics
If the value is invalid UTF-8. See
Arg::allow_invalid_utf8
.
If id
is is not a valid argument or group name.
Examples
let matches = Command::new("myapp")
.arg(arg!([length] "Set the length to use as a pos whole num i.e. 20"))
.get_matches_from(&["test", "12"]);
// Specify the type explicitly (or use turbofish)
let len: u32 = matches.value_of_t("length").unwrap_or_else(|e| e.exit());
assert_eq!(len, 12);
// You can often leave the type for rustc to figure out
let also_len = matches.value_of_t("length").unwrap_or_else(|e| e.exit());
// Something that expects u32
let _: u32 = also_len;
Examples found in repository?
More examples
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fn main() {
let matches = command!()
.arg(
arg!(<PORT>)
.help("Network port to use")
.validator(port_in_range),
)
.get_matches();
// Note, it's safe to call unwrap() because the arg is required
let port: usize = matches
.value_of_t("PORT")
.expect("'PORT' is required and parsing will fail if its missing");
println!("PORT = {}", port);
}
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fn main() {
let matches = command!()
.arg(
arg!(<PORT>)
.help("Network port to use")
.validator(|s| s.parse::<usize>()),
)
.get_matches();
// Note, it's safe to call unwrap() because the arg is required
let port: usize = matches
.value_of_t("PORT")
.expect("'PORT' is required and parsing will fail if its missing");
println!("PORT = {}", port);
}
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fn main() {
let matches = command!()
.arg(
arg!(<MODE>)
.help("What mode to run the program in")
.possible_values(Mode::possible_values()),
)
.get_matches();
// Note, it's safe to call unwrap() because the arg is required
match matches
.value_of_t("MODE")
.expect("'MODE' is required and parsing will fail if its missing")
{
Mode::Fast => {
println!("Hare");
}
Mode::Slow => {
println!("Tortoise");
}
}
}
sourcepub fn value_of_t_or_exit<R>(&self, name: &str) -> R where
R: FromStr,
<R as FromStr>::Err: Display,
pub fn value_of_t_or_exit<R>(&self, name: &str) -> R where
R: FromStr,
<R as FromStr>::Err: Display,
Parse the value (with FromStr
) of a specific option or positional argument.
If either the value is not present or parsing failed, exits the program.
Panics
If the value is invalid UTF-8. See
Arg::allow_invalid_utf8
.
If id
is is not a valid argument or group name.
Examples
let matches = Command::new("myapp")
.arg(arg!([length] "Set the length to use as a pos whole num i.e. 20"))
.get_matches_from(&["test", "12"]);
// Specify the type explicitly (or use turbofish)
let len: u32 = matches.value_of_t_or_exit("length");
assert_eq!(len, 12);
// You can often leave the type for rustc to figure out
let also_len = matches.value_of_t_or_exit("length");
// Something that expects u32
let _: u32 = also_len;
sourcepub fn values_of_t<R>(&self, name: &str) -> Result<Vec<R>, Error> where
R: FromStr,
<R as FromStr>::Err: Display,
pub fn values_of_t<R>(&self, name: &str) -> Result<Vec<R>, Error> where
R: FromStr,
<R as FromStr>::Err: Display,
Parse the values (with FromStr
) of a specific option or positional argument.
There are two types of errors, parse failures and those where the argument wasn’t present
(such as a non-required argument). Check ErrorKind
to distinguish them.
NOTE: If getting a value for an option or positional argument that allows multiples,
prefer ArgMatches::values_of_t
as this method will only return the first
value.
Panics
If the value is invalid UTF-8. See
Arg::allow_invalid_utf8
.
If id
is is not a valid argument or group name.
Examples
let matches = Command::new("myapp")
.arg(arg!([length] ... "A sequence of integers because integers are neat!"))
.get_matches_from(&["test", "12", "77", "40"]);
// Specify the type explicitly (or use turbofish)
let len: Vec<u32> = matches.values_of_t("length").unwrap_or_else(|e| e.exit());
assert_eq!(len, vec![12, 77, 40]);
// You can often leave the type for rustc to figure out
let also_len = matches.values_of_t("length").unwrap_or_else(|e| e.exit());
// Something that expects Vec<u32>
let _: Vec<u32> = also_len;
sourcepub fn values_of_t_or_exit<R>(&self, name: &str) -> Vec<R>ⓘNotable traits for Vec<u8, A>impl<A> Write for Vec<u8, A> where
A: Allocator,
where
R: FromStr,
<R as FromStr>::Err: Display,
pub fn values_of_t_or_exit<R>(&self, name: &str) -> Vec<R>ⓘNotable traits for Vec<u8, A>impl<A> Write for Vec<u8, A> where
A: Allocator,
where
R: FromStr,
<R as FromStr>::Err: Display,
A: Allocator,
Parse the values (with FromStr
) of a specific option or positional argument.
If parsing (of any value) has failed, exits the program.
Panics
If the value is invalid UTF-8. See
Arg::allow_invalid_utf8
.
If id
is is not a valid argument or group name.
Examples
let matches = Command::new("myapp")
.arg(arg!([length] ... "A sequence of integers because integers are neat!"))
.get_matches_from(&["test", "12", "77", "40"]);
// Specify the type explicitly (or use turbofish)
let len: Vec<u32> = matches.values_of_t_or_exit("length");
assert_eq!(len, vec![12, 77, 40]);
// You can often leave the type for rustc to figure out
let also_len = matches.values_of_t_or_exit("length");
// Something that expects Vec<u32>
let _: Vec<u32> = also_len;
sourcepub fn is_present<T: Key>(&self, id: T) -> bool
pub fn is_present<T: Key>(&self, id: T) -> bool
Check if an argument was present at runtime.
NOTE: This will always return true
if default_value
has been set.
occurrences_of
can be used to check if a value is present at runtime.
Panics
If id
is is not a valid argument or group name.
Examples
let m = Command::new("myprog")
.arg(Arg::new("debug")
.short('d'))
.get_matches_from(vec![
"myprog", "-d"
]);
assert!(m.is_present("debug"));
Examples found in repository?
More examples
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
fn from_arg_matches(matches: &ArgMatches) -> Result<Self, Error> {
Ok(Self {
foo: matches.is_present("foo"),
bar: matches.is_present("bar"),
quuz: matches.value_of("quuz").map(|quuz| quuz.to_owned()),
})
}
fn update_from_arg_matches(&mut self, matches: &ArgMatches) -> Result<(), Error> {
self.foo |= matches.is_present("foo");
self.bar |= matches.is_present("bar");
if let Some(quuz) = matches.value_of("quuz") {
self.quuz = Some(quuz.to_owned());
}
Ok(())
}
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
fn main() {
let cli = Command::new("CLI").arg(arg!(-b - -built));
// Augment built args with derived args
let cli = DerivedArgs::augment_args(cli);
let matches = cli.get_matches();
println!("Value of built: {:?}", matches.is_present("built"));
println!(
"Value of derived via ArgMatches: {:?}",
matches.is_present("derived")
);
// Since DerivedArgs implements FromArgMatches, we can extract it from the unstructured ArgMatches.
// This is the main benefit of using derived arguments.
let derived_matches = DerivedArgs::from_arg_matches(&matches)
.map_err(|err| err.exit())
.unwrap();
println!("Value of derived: {:#?}", derived_matches);
}
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
fn main() {
let matches = command!()
.arg(arg!(eff: -f))
.arg(arg!(pea: -p <PEAR>).required(false))
.arg(
arg!(slop: [SLOP]).multiple_occurrences(true).last(true), // Indicates that `slop` is only accessible after `--`.
)
.get_matches();
// This is what will happen with `myprog -f -p=bob -- sloppy slop slop`...
println!("-f used: {:?}", matches.is_present("eff")); // -f used: true
println!("-p's value: {:?}", matches.value_of("pea")); // -p's value: Some("bob")
println!(
"'slops' values: {:?}",
matches
.values_of("slop")
.map(|vals| vals.collect::<Vec<_>>())
.unwrap_or_default()
); // 'slops' values: Some(["sloppy", "slop", "slop"])
// Continued program logic goes here...
}
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fn main() {
let matches = command!()
.arg(arg!([name] "Optional name to operate on"))
.arg(
arg!(
-c --config <FILE> "Sets a custom config file"
)
// We don't have syntax yet for optional options, so manually calling `required`
.required(false)
// Support non-UTF8 paths
.allow_invalid_utf8(true),
)
.arg(arg!(
-d --debug ... "Turn debugging information on"
))
.subcommand(
Command::new("test")
.about("does testing things")
.arg(arg!(-l --list "lists test values")),
)
.get_matches();
// You can check the value provided by positional arguments, or option arguments
if let Some(name) = matches.value_of("name") {
println!("Value for name: {}", name);
}
if let Some(raw_config) = matches.value_of_os("config") {
let config_path = Path::new(raw_config);
println!("Value for config: {}", config_path.display());
}
// You can see how many times a particular flag or argument occurred
// Note, only flags can have multiple occurrences
match matches.occurrences_of("debug") {
0 => println!("Debug mode is off"),
1 => println!("Debug mode is kind of on"),
2 => println!("Debug mode is on"),
_ => println!("Don't be crazy"),
}
// You can check for the existence of subcommands, and if found use their
// matches just as you would the top level cmd
if let Some(matches) = matches.subcommand_matches("test") {
// "$ myapp test" was run
if matches.is_present("list") {
// "$ myapp test -l" was run
println!("Printing testing lists...");
} else {
println!("Not printing testing lists...");
}
}
// Continued program logic goes here...
}
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69
fn main() {
// Create application like normal
let matches = command!()
// Add the version arguments
.arg(arg!(--"set-ver" <VER> "set version manually").required(false))
.arg(arg!(--major "auto inc major"))
.arg(arg!(--minor "auto inc minor"))
.arg(arg!(--patch "auto inc patch"))
// Create a group, make it required, and add the above arguments
.group(
ArgGroup::new("vers")
.required(true)
.args(&["set-ver", "major", "minor", "patch"]),
)
// Arguments can also be added to a group individually, these two arguments
// are part of the "input" group which is not required
.arg(arg!([INPUT_FILE] "some regular input").group("input"))
.arg(
arg!(--"spec-in" <SPEC_IN> "some special input argument")
.required(false)
.group("input"),
)
// Now let's assume we have a -c [config] argument which requires one of
// (but **not** both) the "input" arguments
.arg(arg!(config: -c <CONFIG>).required(false).requires("input"))
.get_matches();
// Let's assume the old version 1.2.3
let mut major = 1;
let mut minor = 2;
let mut patch = 3;
// See if --set-ver was used to set the version manually
let version = if let Some(ver) = matches.value_of("set-ver") {
ver.to_string()
} else {
// Increment the one requested (in a real program, we'd reset the lower numbers)
let (maj, min, pat) = (
matches.is_present("major"),
matches.is_present("minor"),
matches.is_present("patch"),
);
match (maj, min, pat) {
(true, _, _) => major += 1,
(_, true, _) => minor += 1,
(_, _, true) => patch += 1,
_ => unreachable!(),
};
format!("{}.{}.{}", major, minor, patch)
};
println!("Version: {}", version);
// Check for usage of -c
if matches.is_present("config") {
let input = matches
.value_of("INPUT_FILE")
.unwrap_or_else(|| matches.value_of("spec-in").unwrap());
println!(
"Doing work using input {} and config {}",
input,
matches.value_of("config").unwrap()
);
}
}
sourcepub fn value_source<T: Key>(&self, id: T) -> Option<ValueSource>
pub fn value_source<T: Key>(&self, id: T) -> Option<ValueSource>
sourcepub fn occurrences_of<T: Key>(&self, id: T) -> u64
pub fn occurrences_of<T: Key>(&self, id: T) -> u64
The number of times an argument was used at runtime.
If an argument isn’t present it will return 0
.
NOTE: This returns the number of times the argument was used, not the number of
values. For example, -o val1 val2 val3 -o val4
would return 2
(2 occurrences, but 4
values). See Arg::multiple_occurrences.
Panics
If id
is is not a valid argument or group name.
Examples
let m = Command::new("myprog")
.arg(Arg::new("debug")
.short('d')
.multiple_occurrences(true))
.get_matches_from(vec![
"myprog", "-d", "-d", "-d"
]);
assert_eq!(m.occurrences_of("debug"), 3);
This next example shows that counts actual uses of the argument, not just -
’s
let m = Command::new("myprog")
.arg(Arg::new("debug")
.short('d')
.multiple_occurrences(true))
.arg(Arg::new("flag")
.short('f'))
.get_matches_from(vec![
"myprog", "-ddfd"
]);
assert_eq!(m.occurrences_of("debug"), 3);
assert_eq!(m.occurrences_of("flag"), 1);
Examples found in repository?
More examples
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
fn main() {
let cmd = Command::new(env!("CARGO_CRATE_NAME"))
.multicall(true)
.subcommand(
Command::new("busybox")
.arg_required_else_help(true)
.subcommand_value_name("APPLET")
.subcommand_help_heading("APPLETS")
.arg(
Arg::new("install")
.long("install")
.help("Install hardlinks for all subcommands in path")
.exclusive(true)
.takes_value(true)
.default_missing_value("/usr/local/bin")
.use_value_delimiter(false),
)
.subcommands(applet_commands()),
)
.subcommands(applet_commands());
let matches = cmd.get_matches();
let mut subcommand = matches.subcommand();
if let Some(("busybox", cmd)) = subcommand {
if cmd.occurrences_of("install") > 0 {
unimplemented!("Make hardlinks to the executable here");
}
subcommand = cmd.subcommand();
}
match subcommand {
Some(("false", _)) => exit(1),
Some(("true", _)) => exit(0),
_ => unreachable!("parser should ensure only valid subcommand names are used"),
}
}
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fn main() {
let matches = command!()
.arg(arg!([name] "Optional name to operate on"))
.arg(
arg!(
-c --config <FILE> "Sets a custom config file"
)
// We don't have syntax yet for optional options, so manually calling `required`
.required(false)
// Support non-UTF8 paths
.allow_invalid_utf8(true),
)
.arg(arg!(
-d --debug ... "Turn debugging information on"
))
.subcommand(
Command::new("test")
.about("does testing things")
.arg(arg!(-l --list "lists test values")),
)
.get_matches();
// You can check the value provided by positional arguments, or option arguments
if let Some(name) = matches.value_of("name") {
println!("Value for name: {}", name);
}
if let Some(raw_config) = matches.value_of_os("config") {
let config_path = Path::new(raw_config);
println!("Value for config: {}", config_path.display());
}
// You can see how many times a particular flag or argument occurred
// Note, only flags can have multiple occurrences
match matches.occurrences_of("debug") {
0 => println!("Debug mode is off"),
1 => println!("Debug mode is kind of on"),
2 => println!("Debug mode is on"),
_ => println!("Don't be crazy"),
}
// You can check for the existence of subcommands, and if found use their
// matches just as you would the top level cmd
if let Some(matches) = matches.subcommand_matches("test") {
// "$ myapp test" was run
if matches.is_present("list") {
// "$ myapp test -l" was run
println!("Printing testing lists...");
} else {
println!("Not printing testing lists...");
}
}
// Continued program logic goes here...
}
sourcepub fn index_of<T: Key>(&self, id: T) -> Option<usize>
pub fn index_of<T: Key>(&self, id: T) -> Option<usize>
The first index of that an argument showed up.
Indices are similar to argv indices, but are not exactly 1:1.
For flags (i.e. those arguments which don’t have an associated value), indices refer
to occurrence of the switch, such as -f
, or --flag
. However, for options the indices
refer to the values -o val
would therefore not represent two distinct indices, only the
index for val
would be recorded. This is by design.
Besides the flag/option discrepancy, the primary difference between an argv index and clap index, is that clap continues counting once all arguments have properly separated, whereas an argv index does not.
The examples should clear this up.
NOTE: If an argument is allowed multiple times, this method will only give the first
index. See ArgMatches::indices_of
.
Panics
If id
is is not a valid argument or group name.
Examples
The argv indices are listed in the comments below. See how they correspond to the clap
indices. Note that if it’s not listed in a clap index, this is because it’s not saved in
in an ArgMatches
struct for querying.
let m = Command::new("myapp")
.arg(Arg::new("flag")
.short('f'))
.arg(Arg::new("option")
.short('o')
.takes_value(true))
.get_matches_from(vec!["myapp", "-f", "-o", "val"]);
// ARGV indices: ^0 ^1 ^2 ^3
// clap indices: ^1 ^3
assert_eq!(m.index_of("flag"), Some(1));
assert_eq!(m.index_of("option"), Some(3));
Now notice, if we use one of the other styles of options:
let m = Command::new("myapp")
.arg(Arg::new("flag")
.short('f'))
.arg(Arg::new("option")
.short('o')
.takes_value(true))
.get_matches_from(vec!["myapp", "-f", "-o=val"]);
// ARGV indices: ^0 ^1 ^2
// clap indices: ^1 ^3
assert_eq!(m.index_of("flag"), Some(1));
assert_eq!(m.index_of("option"), Some(3));
Things become much more complicated, or clear if we look at a more complex combination of flags. Let’s also throw in the final option style for good measure.
let m = Command::new("myapp")
.arg(Arg::new("flag")
.short('f'))
.arg(Arg::new("flag2")
.short('F'))
.arg(Arg::new("flag3")
.short('z'))
.arg(Arg::new("option")
.short('o')
.takes_value(true))
.get_matches_from(vec!["myapp", "-fzF", "-oval"]);
// ARGV indices: ^0 ^1 ^2
// clap indices: ^1,2,3 ^5
//
// clap sees the above as 'myapp -f -z -F -o val'
// ^0 ^1 ^2 ^3 ^4 ^5
assert_eq!(m.index_of("flag"), Some(1));
assert_eq!(m.index_of("flag2"), Some(3));
assert_eq!(m.index_of("flag3"), Some(2));
assert_eq!(m.index_of("option"), Some(5));
One final combination of flags/options to see how they combine:
let m = Command::new("myapp")
.arg(Arg::new("flag")
.short('f'))
.arg(Arg::new("flag2")
.short('F'))
.arg(Arg::new("flag3")
.short('z'))
.arg(Arg::new("option")
.short('o')
.takes_value(true))
.get_matches_from(vec!["myapp", "-fzFoval"]);
// ARGV indices: ^0 ^1
// clap indices: ^1,2,3^5
//
// clap sees the above as 'myapp -f -z -F -o val'
// ^0 ^1 ^2 ^3 ^4 ^5
assert_eq!(m.index_of("flag"), Some(1));
assert_eq!(m.index_of("flag2"), Some(3));
assert_eq!(m.index_of("flag3"), Some(2));
assert_eq!(m.index_of("option"), Some(5));
The last part to mention is when values are sent in multiple groups with a delimiter.
let m = Command::new("myapp")
.arg(Arg::new("option")
.short('o')
.use_value_delimiter(true)
.multiple_values(true))
.get_matches_from(vec!["myapp", "-o=val1,val2,val3"]);
// ARGV indices: ^0 ^1
// clap indices: ^2 ^3 ^4
//
// clap sees the above as 'myapp -o val1 val2 val3'
// ^0 ^1 ^2 ^3 ^4
assert_eq!(m.index_of("option"), Some(2));
assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2, 3, 4]);
sourcepub fn indices_of<T: Key>(&self, id: T) -> Option<Indices<'_>>
pub fn indices_of<T: Key>(&self, id: T) -> Option<Indices<'_>>
All indices an argument appeared at when parsing.
Indices are similar to argv indices, but are not exactly 1:1.
For flags (i.e. those arguments which don’t have an associated value), indices refer
to occurrence of the switch, such as -f
, or --flag
. However, for options the indices
refer to the values -o val
would therefore not represent two distinct indices, only the
index for val
would be recorded. This is by design.
NOTE: For more information about how clap indices compared to argv indices, see
ArgMatches::index_of
Panics
If id
is is not a valid argument or group name.
Examples
let m = Command::new("myapp")
.arg(Arg::new("option")
.short('o')
.use_value_delimiter(true)
.multiple_values(true))
.get_matches_from(vec!["myapp", "-o=val1,val2,val3"]);
// ARGV indices: ^0 ^1
// clap indices: ^2 ^3 ^4
//
// clap sees the above as 'myapp -o val1 val2 val3'
// ^0 ^1 ^2 ^3 ^4
assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2, 3, 4]);
Another quick example is when flags and options are used together
let m = Command::new("myapp")
.arg(Arg::new("option")
.short('o')
.takes_value(true)
.multiple_occurrences(true))
.arg(Arg::new("flag")
.short('f')
.multiple_occurrences(true))
.get_matches_from(vec!["myapp", "-o", "val1", "-f", "-o", "val2", "-f"]);
// ARGV indices: ^0 ^1 ^2 ^3 ^4 ^5 ^6
// clap indices: ^2 ^3 ^5 ^6
assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2, 5]);
assert_eq!(m.indices_of("flag").unwrap().collect::<Vec<_>>(), &[3, 6]);
One final example, which is an odd case; if we don’t use value delimiter as we did with
the first example above instead of val1
, val2
and val3
all being distinc values, they
would all be a single value of val1,val2,val3
, in which case they’d only receive a single
index.
let m = Command::new("myapp")
.arg(Arg::new("option")
.short('o')
.takes_value(true)
.multiple_values(true))
.get_matches_from(vec!["myapp", "-o=val1,val2,val3"]);
// ARGV indices: ^0 ^1
// clap indices: ^2
//
// clap sees the above as 'myapp -o "val1,val2,val3"'
// ^0 ^1 ^2
assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2]);
sourcepub fn subcommand(&self) -> Option<(&str, &ArgMatches)>
pub fn subcommand(&self) -> Option<(&str, &ArgMatches)>
The name and ArgMatches
of the current subcommand.
Subcommand values are put in a child ArgMatches
Returns None
if the subcommand wasn’t present at runtime,
Examples
let app_m = Command::new("git")
.subcommand(Command::new("clone"))
.subcommand(Command::new("push"))
.subcommand(Command::new("commit"))
.get_matches();
match app_m.subcommand() {
Some(("clone", sub_m)) => {}, // clone was used
Some(("push", sub_m)) => {}, // push was used
Some(("commit", sub_m)) => {}, // commit was used
_ => {}, // Either no subcommand or one not tested for...
}
Another useful scenario is when you want to support third party, or external, subcommands. In these cases you can’t know the subcommand name ahead of time, so use a variable instead with pattern matching!
// Assume there is an external subcommand named "subcmd"
let app_m = Command::new("myprog")
.allow_external_subcommands(true)
.get_matches_from(vec![
"myprog", "subcmd", "--option", "value", "-fff", "--flag"
]);
// All trailing arguments will be stored under the subcommand's sub-matches using an empty
// string argument name
match app_m.subcommand() {
Some((external, sub_m)) => {
let ext_args: Vec<&str> = sub_m.values_of("").unwrap().collect();
assert_eq!(external, "subcmd");
assert_eq!(ext_args, ["--option", "value", "-fff", "--flag"]);
},
_ => {},
}
Examples found in repository?
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
fn main() {
let matches = command!()
.propagate_version(true)
.subcommand_required(true)
.arg_required_else_help(true)
.subcommand(
Command::new("add")
.about("Adds files to myapp")
.arg(arg!([NAME])),
)
.get_matches();
match matches.subcommand() {
Some(("add", sub_matches)) => println!(
"'myapp add' was used, name is: {:?}",
sub_matches.value_of("NAME")
),
_ => unreachable!("Exhausted list of subcommands and subcommand_required prevents `None`"),
}
}
More examples
22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49
fn from_arg_matches(matches: &ArgMatches) -> Result<Self, Error> {
match matches.subcommand() {
Some(("add", args)) => Ok(Self::Add(AddArgs::from_arg_matches(args)?)),
Some(("remove", args)) => Ok(Self::Remove(RemoveArgs::from_arg_matches(args)?)),
Some((_, _)) => Err(Error::raw(
ErrorKind::UnrecognizedSubcommand,
"Valid subcommands are `add` and `remove`",
)),
None => Err(Error::raw(
ErrorKind::MissingSubcommand,
"Valid subcommands are `add` and `remove`",
)),
}
}
fn update_from_arg_matches(&mut self, matches: &ArgMatches) -> Result<(), Error> {
match matches.subcommand() {
Some(("add", args)) => *self = Self::Add(AddArgs::from_arg_matches(args)?),
Some(("remove", args)) => *self = Self::Remove(RemoveArgs::from_arg_matches(args)?),
Some((_, _)) => {
return Err(Error::raw(
ErrorKind::UnrecognizedSubcommand,
"Valid subcommands are `add` and `remove`",
))
}
None => (),
};
Ok(())
}
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
fn main() {
let cmd = clap::Command::new("cargo")
.bin_name("cargo")
.subcommand_required(true)
.subcommand(
clap::command!("example").arg(
clap::arg!(--"manifest-path" <PATH>)
.required(false)
.allow_invalid_utf8(true),
),
);
let matches = cmd.get_matches();
let matches = match matches.subcommand() {
Some(("example", matches)) => matches,
_ => unreachable!("clap should ensure we don't get here"),
};
let manifest_path = matches
.value_of_os("manifest-path")
.map(std::path::PathBuf::from);
println!("{:?}", manifest_path);
}
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fn main() {
let cmd = Command::new(env!("CARGO_CRATE_NAME"))
.multicall(true)
.subcommand(
Command::new("busybox")
.arg_required_else_help(true)
.subcommand_value_name("APPLET")
.subcommand_help_heading("APPLETS")
.arg(
Arg::new("install")
.long("install")
.help("Install hardlinks for all subcommands in path")
.exclusive(true)
.takes_value(true)
.default_missing_value("/usr/local/bin")
.use_value_delimiter(false),
)
.subcommands(applet_commands()),
)
.subcommands(applet_commands());
let matches = cmd.get_matches();
let mut subcommand = matches.subcommand();
if let Some(("busybox", cmd)) = subcommand {
if cmd.occurrences_of("install") > 0 {
unimplemented!("Make hardlinks to the executable here");
}
subcommand = cmd.subcommand();
}
match subcommand {
Some(("false", _)) => exit(1),
Some(("true", _)) => exit(0),
_ => unreachable!("parser should ensure only valid subcommand names are used"),
}
}
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fn main() {
let matches = cli().get_matches();
match matches.subcommand() {
Some(("clone", sub_matches)) => {
println!(
"Cloning {}",
sub_matches.value_of("REMOTE").expect("required")
);
}
Some(("push", sub_matches)) => {
println!(
"Pushing to {}",
sub_matches.value_of("REMOTE").expect("required")
);
}
Some(("add", sub_matches)) => {
let paths = sub_matches
.values_of_os("PATH")
.unwrap_or_default()
.map(PathBuf::from)
.collect::<Vec<_>>();
println!("Adding {:?}", paths);
}
Some(("stash", sub_matches)) => {
let stash_command = sub_matches.subcommand().unwrap_or(("push", sub_matches));
match stash_command {
("apply", sub_matches) => {
let stash = sub_matches.value_of("STASH");
println!("Applying {:?}", stash);
}
("pop", sub_matches) => {
let stash = sub_matches.value_of("STASH");
println!("Popping {:?}", stash);
}
("push", sub_matches) => {
let message = sub_matches.value_of("message");
println!("Pushing {:?}", message);
}
(name, _) => {
unreachable!("Unsupported subcommand `{}`", name)
}
}
}
Some((ext, sub_matches)) => {
let args = sub_matches
.values_of_os("")
.unwrap_or_default()
.collect::<Vec<_>>();
println!("Calling out to {:?} with {:?}", ext, args);
}
_ => unreachable!(), // If all subcommands are defined above, anything else is unreachabe!()
}
// Continued program logic goes here...
}
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fn main() {
let matches = Command::new("pacman")
.about("package manager utility")
.version("5.2.1")
.subcommand_required(true)
.arg_required_else_help(true)
.author("Pacman Development Team")
// Query subcommand
//
// Only a few of its arguments are implemented below.
.subcommand(
Command::new("query")
.short_flag('Q')
.long_flag("query")
.about("Query the package database.")
.arg(
Arg::new("search")
.short('s')
.long("search")
.help("search locally installed packages for matching strings")
.conflicts_with("info")
.takes_value(true)
.multiple_values(true),
)
.arg(
Arg::new("info")
.long("info")
.short('i')
.conflicts_with("search")
.help("view package information")
.takes_value(true)
.multiple_values(true),
),
)
// Sync subcommand
//
// Only a few of its arguments are implemented below.
.subcommand(
Command::new("sync")
.short_flag('S')
.long_flag("sync")
.about("Synchronize packages.")
.arg(
Arg::new("search")
.short('s')
.long("search")
.conflicts_with("info")
.takes_value(true)
.multiple_values(true)
.help("search remote repositories for matching strings"),
)
.arg(
Arg::new("info")
.long("info")
.conflicts_with("search")
.short('i')
.help("view package information"),
)
.arg(
Arg::new("package")
.help("packages")
.required_unless_present("search")
.takes_value(true)
.multiple_values(true),
),
)
.get_matches();
match matches.subcommand() {
Some(("sync", sync_matches)) => {
if sync_matches.is_present("search") {
let packages: Vec<_> = sync_matches.values_of("search").unwrap().collect();
let values = packages.join(", ");
println!("Searching for {}...", values);
return;
}
let packages: Vec<_> = sync_matches.values_of("package").unwrap().collect();
let values = packages.join(", ");
if sync_matches.is_present("info") {
println!("Retrieving info for {}...", values);
} else {
println!("Installing {}...", values);
}
}
Some(("query", query_matches)) => {
if let Some(packages) = query_matches.values_of("info") {
let comma_sep = packages.collect::<Vec<_>>().join(", ");
println!("Retrieving info for {}...", comma_sep);
} else if let Some(queries) = query_matches.values_of("search") {
let comma_sep = queries.collect::<Vec<_>>().join(", ");
println!("Searching Locally for {}...", comma_sep);
} else {
println!("Displaying all locally installed packages...");
}
}
_ => unreachable!(), // If all subcommands are defined above, anything else is unreachable
}
}
sourcepub fn subcommand_matches<T: Key>(&self, id: T) -> Option<&ArgMatches>
pub fn subcommand_matches<T: Key>(&self, id: T) -> Option<&ArgMatches>
The ArgMatches
for the current subcommand.
Subcommand values are put in a child ArgMatches
Returns None
if the subcommand wasn’t present at runtime,
Panics
If id
is is not a valid subcommand.
Examples
let app_m = Command::new("myprog")
.arg(Arg::new("debug")
.short('d'))
.subcommand(Command::new("test")
.arg(Arg::new("opt")
.long("option")
.takes_value(true)))
.get_matches_from(vec![
"myprog", "-d", "test", "--option", "val"
]);
// Both parent commands, and child subcommands can have arguments present at the same times
assert!(app_m.is_present("debug"));
// Get the subcommand's ArgMatches instance
if let Some(sub_m) = app_m.subcommand_matches("test") {
// Use the struct like normal
assert_eq!(sub_m.value_of("opt"), Some("val"));
}
Examples found in repository?
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fn main() {
let matches = command!()
.arg(arg!([name] "Optional name to operate on"))
.arg(
arg!(
-c --config <FILE> "Sets a custom config file"
)
// We don't have syntax yet for optional options, so manually calling `required`
.required(false)
// Support non-UTF8 paths
.allow_invalid_utf8(true),
)
.arg(arg!(
-d --debug ... "Turn debugging information on"
))
.subcommand(
Command::new("test")
.about("does testing things")
.arg(arg!(-l --list "lists test values")),
)
.get_matches();
// You can check the value provided by positional arguments, or option arguments
if let Some(name) = matches.value_of("name") {
println!("Value for name: {}", name);
}
if let Some(raw_config) = matches.value_of_os("config") {
let config_path = Path::new(raw_config);
println!("Value for config: {}", config_path.display());
}
// You can see how many times a particular flag or argument occurred
// Note, only flags can have multiple occurrences
match matches.occurrences_of("debug") {
0 => println!("Debug mode is off"),
1 => println!("Debug mode is kind of on"),
2 => println!("Debug mode is on"),
_ => println!("Don't be crazy"),
}
// You can check for the existence of subcommands, and if found use their
// matches just as you would the top level cmd
if let Some(matches) = matches.subcommand_matches("test") {
// "$ myapp test" was run
if matches.is_present("list") {
// "$ myapp test -l" was run
println!("Printing testing lists...");
} else {
println!("Not printing testing lists...");
}
}
// Continued program logic goes here...
}
sourcepub fn subcommand_name(&self) -> Option<&str>
pub fn subcommand_name(&self) -> Option<&str>
The name of the current subcommand.
Returns None
if the subcommand wasn’t present at runtime,
Examples
let app_m = Command::new("git")
.subcommand(Command::new("clone"))
.subcommand(Command::new("push"))
.subcommand(Command::new("commit"))
.get_matches();
match app_m.subcommand_name() {
Some("clone") => {}, // clone was used
Some("push") => {}, // push was used
Some("commit") => {}, // commit was used
_ => {}, // Either no subcommand or one not tested for...
}
Examples found in repository?
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fn main() {
let cmd = Command::new(env!("CARGO_CRATE_NAME"))
.arg_required_else_help(true)
.subcommand_value_name("APPLET")
.subcommand_help_heading("APPLETS")
.subcommand(Command::new("hostname").about("show hostname part of FQDN"))
.subcommand(Command::new("dnsdomainname").about("show domain name part of FQDN"));
let cmd = cmd.multicall(true);
match cmd.get_matches().subcommand_name() {
Some("hostname") => println!("www"),
Some("dnsdomainname") => println!("example.com"),
_ => unreachable!("parser should ensure only valid subcommand names are used"),
}
}
Trait Implementations
sourceimpl Clone for ArgMatches
impl Clone for ArgMatches
sourcefn clone(&self) -> ArgMatches
fn clone(&self) -> ArgMatches
Returns a copy of the value. Read more
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
sourceimpl Debug for ArgMatches
impl Debug for ArgMatches
sourceimpl Default for ArgMatches
impl Default for ArgMatches
sourcefn default() -> ArgMatches
fn default() -> ArgMatches
Returns the “default value” for a type. Read more
sourceimpl PartialEq<ArgMatches> for ArgMatches
impl PartialEq<ArgMatches> for ArgMatches
sourcefn eq(&self, other: &ArgMatches) -> bool
fn eq(&self, other: &ArgMatches) -> bool
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
sourcefn ne(&self, other: &ArgMatches) -> bool
fn ne(&self, other: &ArgMatches) -> bool
This method tests for !=
.
impl Eq for ArgMatches
impl StructuralEq for ArgMatches
impl StructuralPartialEq for ArgMatches
Auto Trait Implementations
impl RefUnwindSafe for ArgMatches
impl Send for ArgMatches
impl Sync for ArgMatches
impl Unpin for ArgMatches
impl UnwindSafe for ArgMatches
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<Q, K> Equivalent<K> for Q where
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Q where
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
sourcefn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
Compare self to key
and return true
if they are equal.
sourceimpl<T> ToOwned for T where
T: Clone,
impl<T> ToOwned for T where
T: Clone,
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
sourcefn clone_into(&self, target: &mut T)
fn clone_into(&self, target: &mut T)
toowned_clone_into
)Uses borrowed data to replace owned data, usually by cloning. Read more