//! 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, path::PathBuf}; use bstr::BString; /// 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, /// Additional information to be passed to the spawned command. pub context: Option<Context>, /// 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, /// If `true` (default `true` on windows and `false` everywhere else) /// we will see if it's safe to manually invoke `command` after splitting /// its arguments as a shell would do. /// Note that outside of windows, it's generally not advisable as this /// removes support for literal shell scripts with shell-builtins. /// /// This mimics the behaviour we see with `git` on windows, which also /// won't invoke the shell there at all. /// /// Only effective if `use_shell` is `true` as well, as the shell will /// be used as a fallback if it's not possible to split arguments as /// the command-line contains 'scripting'. pub allow_manual_arg_splitting: bool,} /// Additional information that is relevant to spawned processes, which typically receive/// a wealth of contextual information when spawned from `git`.////// See [the git source code](https://github.com/git/git/blob/cfb8a6e9a93adbe81efca66e6110c9b4d2e57169/git.c#L191)/// for details.#[derive(Debug, Default, Clone)]pub struct Context { /// The `.git` directory that contains the repository. /// /// If set, it will be used to set the the `GIT_DIR` environment variable. pub git_dir: Option<PathBuf>, /// Set the `GIT_WORK_TREE` environment variable with the given path. pub worktree_dir: Option<PathBuf>, /// If `true`, set `GIT_NO_REPLACE_OBJECTS` to `1`, which turns off object replacements, or `0` otherwise. /// If `None`, the variable won't be set. pub no_replace_objects: Option<bool>, /// Set the `GIT_NAMESPACE` variable with the given value, effectively namespacing all /// operations on references. pub ref_namespace: Option<BString>, /// If `true`, set `GIT_LITERAL_PATHSPECS` to `1`, which makes globs literal and prefixes as well, or `0` otherwise. /// If `None`, the variable won't be set. pub literal_pathspecs: Option<bool>, /// If `true`, set `GIT_GLOB_PATHSPECS` to `1`, which lets wildcards not match the `/` character, and equals the `:(glob)` prefix. /// If `false`, set `GIT_NOGLOB_PATHSPECS` to `1` which lets globs match only themselves. /// If `None`, the variable won't be set. pub glob_pathspecs: Option<bool>, /// If `true`, set `GIT_ICASE_PATHSPECS` to `1`, to let patterns match case-insensitively, or `0` otherwise. /// If `None`, the variable won't be set. pub icase_pathspecs: Option<bool>, /// If `true`, inherit `stderr` just like it's the default when spawning processes. /// If `false`, suppress all stderr output. /// If not `None`, this will override any value set with [`Prepare::stderr()`]. pub stderr: Option<bool>,} mod prepare { use std::{ ffi::OsString, process::{Command, Stdio}, }; use bstr::ByteSlice; use crate::{Context, Prepare}; /// Builder impl Prepare { /// If called, the command will not be executed directly, but with `sh`, but only if the /// command passed to [`prepare`](super::prepare()) requires this. /// /// 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 } /// Set additional `ctx` to be used when spawning the process. /// /// Note that this is a must for most kind of commands that `git` usually spawns, /// as at least they need to know the correct `git` repository to function. pub fn with_context(mut self, ctx: Context) -> Self { self.context = Some(ctx); self } /// Use a shell, but try to split arguments by hand if this be safely done without a shell. /// /// If that's not the case, use a shell instead. pub fn with_shell_allow_argument_splitting(mut self) -> Self { self.allow_manual_arg_splitting = true; self.with_shell() } /// 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> { let mut cmd = Command::from(self); gix_trace::debug!(cmd = ?cmd); cmd.spawn() } } impl From<Prepare> for Command { fn from(mut prep: Prepare) -> Command { let mut cmd = if prep.use_shell { let split_args = prep .allow_manual_arg_splitting .then(|| { if gix_path::into_bstr(std::borrow::Cow::Borrowed(prep.command.as_ref())) .find_byteset(b"\\|&;<>()$`\n*?[#~%") .is_none() { prep.command .to_str() .and_then(|args| shell_words::split(args).ok().map(Vec::into_iter)) } else { None } }) .flatten(); match split_args { Some(mut args) => { let mut cmd = Command::new(args.next().expect("non-empty input")); cmd.args(args); cmd } None => { 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); if let Some(ctx) = prep.context { if let Some(git_dir) = ctx.git_dir { cmd.env("GIT_DIR", &git_dir); } if let Some(worktree_dir) = ctx.worktree_dir { cmd.env("GIT_WORK_TREE", worktree_dir); } if let Some(value) = ctx.no_replace_objects { cmd.env("GIT_NO_REPLACE_OBJECTS", usize::from(value).to_string()); } if let Some(namespace) = ctx.ref_namespace { cmd.env("GIT_NAMESPACE", gix_path::from_bstring(namespace)); } if let Some(value) = ctx.literal_pathspecs { cmd.env("GIT_LITERAL_PATHSPECS", usize::from(value).to_string()); } if let Some(value) = ctx.glob_pathspecs { cmd.env( if value { "GIT_GLOB_PATHSPECS" } else { "GIT_NOGLOB_PATHSPECS" }, "1", ); } if let Some(value) = ctx.icase_pathspecs { cmd.env("GIT_ICASE_PATHSPECS", usize::from(value).to_string()); } if let Some(stderr) = ctx.stderr { cmd.stderr(if stderr { Stdio::inherit() } else { Stdio::null() }); } } 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 user////// ### Warning////// When using this method, be sure that the invoked program doesn't rely on the current working dir and/or/// environment variables to know its context. If so, call instead [`Prepare::with_context()`] to provide/// additional information.pub fn prepare(cmd: impl Into<OsString>) -> Prepare { Prepare { command: cmd.into(), context: None, stdin: std::process::Stdio::null(), stdout: std::process::Stdio::piped(), stderr: std::process::Stdio::inherit(), args: Vec::new(), env: Vec::new(), use_shell: false, allow_manual_arg_splitting: cfg!(windows), }}
//! 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, path::PathBuf};
use bstr::BString;
/// 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,
/// Additional information to be passed to the spawned command.
pub context: Option<Context>,
/// 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,
/// If `true` (default `true` on windows and `false` everywhere else)
/// we will see if it's safe to manually invoke `command` after splitting
/// its arguments as a shell would do.
/// Note that outside of windows, it's generally not advisable as this
/// removes support for literal shell scripts with shell-builtins.
///
/// This mimics the behaviour we see with `git` on windows, which also
/// won't invoke the shell there at all.
///
/// Only effective if `use_shell` is `true` as well, as the shell will
/// be used as a fallback if it's not possible to split arguments as
/// the command-line contains 'scripting'.
pub allow_manual_arg_splitting: bool,
}
/// Additional information that is relevant to spawned processes, which typically receive
/// a wealth of contextual information when spawned from `git`.
///
/// See [the git source code](https://github.com/git/git/blob/cfb8a6e9a93adbe81efca66e6110c9b4d2e57169/git.c#L191)
/// for details.
#[derive(Debug, Default, Clone)]
pub struct Context {
/// The `.git` directory that contains the repository.
///
/// If set, it will be used to set the the `GIT_DIR` environment variable.
pub git_dir: Option<PathBuf>,
/// Set the `GIT_WORK_TREE` environment variable with the given path.
pub worktree_dir: Option<PathBuf>,
/// If `true`, set `GIT_NO_REPLACE_OBJECTS` to `1`, which turns off object replacements, or `0` otherwise.
/// If `None`, the variable won't be set.
pub no_replace_objects: Option<bool>,
/// Set the `GIT_NAMESPACE` variable with the given value, effectively namespacing all
/// operations on references.
pub ref_namespace: Option<BString>,
/// If `true`, set `GIT_LITERAL_PATHSPECS` to `1`, which makes globs literal and prefixes as well, or `0` otherwise.
/// If `None`, the variable won't be set.
pub literal_pathspecs: Option<bool>,
/// If `true`, set `GIT_GLOB_PATHSPECS` to `1`, which lets wildcards not match the `/` character, and equals the `:(glob)` prefix.
/// If `false`, set `GIT_NOGLOB_PATHSPECS` to `1` which lets globs match only themselves.
/// If `None`, the variable won't be set.
pub glob_pathspecs: Option<bool>,
/// If `true`, set `GIT_ICASE_PATHSPECS` to `1`, to let patterns match case-insensitively, or `0` otherwise.
/// If `None`, the variable won't be set.
pub icase_pathspecs: Option<bool>,
/// If `true`, inherit `stderr` just like it's the default when spawning processes.
/// If `false`, suppress all stderr output.
/// If not `None`, this will override any value set with [`Prepare::stderr()`].
pub stderr: Option<bool>,
}
mod prepare {
use std::{
ffi::OsString,
process::{Command, Stdio},
};
use bstr::ByteSlice;
use crate::{Context, Prepare};
/// Builder
impl Prepare {
/// If called, the command will not be executed directly, but with `sh`, but only if the
/// command passed to [`prepare`](super::prepare()) requires this.
///
/// 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
}
/// Set additional `ctx` to be used when spawning the process.
///
/// Note that this is a must for most kind of commands that `git` usually spawns,
/// as at least they need to know the correct `git` repository to function.
pub fn with_context(mut self, ctx: Context) -> Self {
self.context = Some(ctx);
self
}
/// Use a shell, but try to split arguments by hand if this be safely done without a shell.
///
/// If that's not the case, use a shell instead.
pub fn with_shell_allow_argument_splitting(mut self) -> Self {
self.allow_manual_arg_splitting = true;
self.with_shell()
}
/// 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> {
let mut cmd = Command::from(self);
gix_trace::debug!(cmd = ?cmd);
cmd.spawn()
}
}
impl From<Prepare> for Command {
fn from(mut prep: Prepare) -> Command {
let mut cmd = if prep.use_shell {
let split_args = prep
.allow_manual_arg_splitting
.then(|| {
if gix_path::into_bstr(std::borrow::Cow::Borrowed(prep.command.as_ref()))
.find_byteset(b"\\|&;<>()$`\n*?[#~%")
.is_none()
{
prep.command
.to_str()
.and_then(|args| shell_words::split(args).ok().map(Vec::into_iter))
} else {
None
}
})
.flatten();
match split_args {
Some(mut args) => {
let mut cmd = Command::new(args.next().expect("non-empty input"));
cmd.args(args);
cmd
}
None => {
let mut cmd = Command::new(if cfg!(windows) { "sh" } else { "/bin/sh" });
cmd.arg("-c");
if !prep.args.is_empty() {
prep.command.push(" \"$@\"")
}
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);
if let Some(ctx) = prep.context {
if let Some(git_dir) = ctx.git_dir {
cmd.env("GIT_DIR", &git_dir);
}
if let Some(worktree_dir) = ctx.worktree_dir {
cmd.env("GIT_WORK_TREE", worktree_dir);
}
if let Some(value) = ctx.no_replace_objects {
cmd.env("GIT_NO_REPLACE_OBJECTS", usize::from(value).to_string());
}
if let Some(namespace) = ctx.ref_namespace {
cmd.env("GIT_NAMESPACE", gix_path::from_bstring(namespace));
}
if let Some(value) = ctx.literal_pathspecs {
cmd.env("GIT_LITERAL_PATHSPECS", usize::from(value).to_string());
}
if let Some(value) = ctx.glob_pathspecs {
cmd.env(
if value {
"GIT_GLOB_PATHSPECS"
} else {
"GIT_NOGLOB_PATHSPECS"
},
"1",
);
}
if let Some(value) = ctx.icase_pathspecs {
cmd.env("GIT_ICASE_PATHSPECS", usize::from(value).to_string());
}
if let Some(stderr) = ctx.stderr {
cmd.stderr(if stderr { Stdio::inherit() } else { Stdio::null() });
}
}
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 user
///
/// ### Warning
///
/// When using this method, be sure that the invoked program doesn't rely on the current working dir and/or
/// environment variables to know its context. If so, call instead [`Prepare::with_context()`] to provide
/// additional information.
pub fn prepare(cmd: impl Into<OsString>) -> Prepare {
Prepare {
command: cmd.into(),
context: None,
stdin: std::process::Stdio::null(),
stdout: std::process::Stdio::piped(),
stderr: std::process::Stdio::inherit(),
args: Vec::new(),
env: Vec::new(),
use_shell: false,
allow_manual_arg_splitting: cfg!(windows),
}
}