//! Launch commands very similarly to `Command`, but with `git` specific capabilities and adjustments.#![deny(rust_2018_idioms, missing_docs)]#![forbid(unsafe_code)] use std::ffi::OsString; /// A structure to keep settings to use when invoking a command via [`spawn()`][Prepare::spawn()], after creating it with [`prepare()`].pub struct Prepare {    /// The command to invoke (either with or without shell depending on `use_shell`.    pub command: OsString,    /// The way standard input is configured.    pub stdin: std::process::Stdio,    /// The way standard output is configured.    pub stdout: std::process::Stdio,    /// The way standard error is configured.    pub stderr: std::process::Stdio,    /// The arguments to pass to the spawned process.    pub args: Vec<OsString>,    /// environment variables to set in the spawned process.    pub env: Vec<(OsString, OsString)>,    /// If `true`, we will use `sh` to execute the `command`.    pub use_shell: bool,} mod prepare {    use std::{        ffi::OsString,        process::{Command, Stdio},    };     use bstr::ByteSlice;     use crate::Prepare;     /// Builder    impl Prepare {        /// If called, the command will not be executed directly, but with `sh`.        ///        /// This also allows to pass shell scripts as command, or use commands that contain arguments which are subsequently        /// parsed by `sh`.        pub fn with_shell(mut self) -> Self {            self.use_shell = self.command.to_str().map_or(true, |cmd| {                cmd.as_bytes().find_byteset(b"|&;<>()$`\\\"' \t\n*?[#~=%").is_some()            });            self        }         /// Unconditionally turn off using the shell when spawning the command.        /// Note that not using the shell is the default so an effective use of this method        /// is some time after [`with_shell()`][Prepare::with_shell()] was called.        pub fn without_shell(mut self) -> Self {            self.use_shell = false;            self        }         /// Configure the process to use `stdio` for _stdin.        pub fn stdin(mut self, stdio: Stdio) -> Self {            self.stdin = stdio;            self        }        /// Configure the process to use `stdio` for _stdout_.        pub fn stdout(mut self, stdio: Stdio) -> Self {            self.stdout = stdio;            self        }        /// Configure the process to use `stdio` for _stderr.        pub fn stderr(mut self, stdio: Stdio) -> Self {            self.stderr = stdio;            self        }         /// Add `arg` to the list of arguments to call the command with.        pub fn arg(mut self, arg: impl Into<OsString>) -> Self {            self.args.push(arg.into());            self        }         /// Add `args` to the list of arguments to call the command with.        pub fn args(mut self, args: impl IntoIterator<Item = impl Into<OsString>>) -> Self {            self.args                .append(&mut args.into_iter().map(Into::into).collect::<Vec<_>>());            self        }         /// Add `key` with `value` to the environment of the spawned command.        pub fn env(mut self, key: impl Into<OsString>, value: impl Into<OsString>) -> Self {            self.env.push((key.into(), value.into()));            self        }    }     /// Finalization    impl Prepare {        /// Spawn the command as configured.        pub fn spawn(self) -> std::io::Result<std::process::Child> {            Command::from(self).spawn()        }    }     impl From<Prepare> for Command {        fn from(mut prep: Prepare) -> Command {            let mut cmd = if prep.use_shell {                let mut cmd = Command::new(if cfg!(windows) { "sh" } else { "/bin/sh" });                cmd.arg("-c");                if !prep.args.is_empty() {                    prep.command.push(" \"$@\"")                }                cmd.arg(prep.command);                cmd.arg("--");                cmd            } else {                Command::new(prep.command)            };            cmd.stdin(prep.stdin)                .stdout(prep.stdout)                .stderr(prep.stderr)                .envs(prep.env)                .args(prep.args);            cmd        }    }} /// Prepare `cmd` for [spawning][std::process::Command::spawn()] by configuring it with various builder methods.////// Note that the default IO is configured for typical API usage, that is////// - `stdin` is null to prevent blocking unexpectedly on consumption of stdin/// - `stdout` is captured for consumption by the caller/// - `stderr` is inherited to allow the command to provide context to the userpub fn prepare(cmd: impl Into<OsString>) -> Prepare {    Prepare {        command: cmd.into(),        stdin: std::process::Stdio::null(),        stdout: std::process::Stdio::piped(),        stderr: std::process::Stdio::inherit(),        args: Vec::new(),        env: Vec::new(),        use_shell: false,    }}