From a2fbdd338588a9574e1506db7e61ea360d2e08f0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Th=C3=A4ter?= <ct@pipapo.org>
Date: Fri, 23 Jul 2021 19:16:46 +0200
Subject: [PATCH 1/7] implement `std::process::Command::args_clear()`
see #87379
Only unix implementation yet.
---
library/std/src/lib.rs | 1 +
library/std/src/process.rs | 32 +++++++++++++++++++
library/std/src/process/tests.rs | 26 +++++++++++++++
.../src/sys/unix/process/process_common.rs | 9 ++++++
4 files changed, 68 insertions(+)
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 67846e7883570..6d612abcc98a2 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -306,6 +306,7 @@
#![feature(min_specialization)]
#![feature(mixed_integer_ops)]
#![feature(must_not_suspend)]
+#![feature(mutate_command_args)]
#![feature(needs_panic_runtime)]
#![feature(negative_impls)]
#![feature(never_type)]
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index 4e9fd51f28229..7e39952ffc44f 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -648,6 +648,38 @@ impl Command {
self
}
+ /// Clears the argument array.
+ ///
+ /// When one wants to restart a Command again with different
+ /// arguments the argument list can to be cleared first.
+ ///
+ /// # Examples
+ ///
+ /// Basic usage:
+ ///
+ /// ```no_run
+ /// #![feature(mutate_command_args)]
+ /// use std::process::Command;
+ ///
+ /// let mut lsdir = Command::new("ls");
+ ///
+ /// lsdir
+ /// .arg("target")
+ /// .spawn()
+ /// .expect("ls command failed to start");
+ ///
+ /// lsdir
+ /// .args_clear()
+ /// .arg("tests")
+ /// .spawn()
+ /// .expect("ls command failed to start");
+ /// ```
+ #[unstable(feature = "mutate_command_args", issue = "87379")]
+ pub fn args_clear(&mut self) -> &mut Command {
+ self.inner.args_clear();
+ self
+ }
+
/// Inserts or updates an environment variable mapping.
///
/// Note that environment variable names are case-insensitive (but case-preserving) on Windows,
diff --git a/library/std/src/process/tests.rs b/library/std/src/process/tests.rs
index 67b747e410732..838ec8a12c40a 100644
--- a/library/std/src/process/tests.rs
+++ b/library/std/src/process/tests.rs
@@ -211,6 +211,32 @@ fn test_wait_with_output_once() {
assert_eq!(stderr, Vec::new());
}
+#[test]
+fn test_args_clear() {
+ let mut prog = Command::new("echo");
+
+ if cfg!(target_os = "windows") {
+ prog.args(&["/C", "echo reset_me"])
+ } else {
+ prog.arg("reset_me")
+ };
+
+ prog.args_clear();
+
+ if cfg!(target_os = "windows") {
+ prog.args(&["/C", "echo hello"]);
+ } else {
+ prog.arg("hello");
+ };
+
+ let Output { status, stdout, stderr } = prog.output().unwrap();
+ let output_str = str::from_utf8(&stdout).unwrap();
+
+ assert!(status.success());
+ assert_eq!(output_str.trim().to_string(), "hello");
+ assert_eq!(stderr, Vec::new());
+}
+
#[cfg(all(unix, not(target_os = "android")))]
pub fn env_cmd() -> Command {
Command::new("env")
diff --git a/library/std/src/sys/unix/process/process_common.rs b/library/std/src/sys/unix/process/process_common.rs
index 7ac2f9d8af75a..daf787de0b5ff 100644
--- a/library/std/src/sys/unix/process/process_common.rs
+++ b/library/std/src/sys/unix/process/process_common.rs
@@ -190,6 +190,15 @@ impl Command {
self.args.push(arg);
}
+ pub fn args_clear(&mut self) {
+ // resize `argv` to 2 (argv[0] and NULL).
+ self.argv.0.truncate(2);
+ self.argv.0[1] = ptr::null();
+
+ // drop all excess args.
+ self.args.truncate(1);
+ }
+
pub fn cwd(&mut self, dir: &OsStr) {
self.cwd = Some(os2c(dir, &mut self.saw_nul));
}
From c420fdc64a12bcff66e45b4131866a7ae9ade0e5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Th=C3=A4ter?= <ct@pipapo.org>
Date: Sat, 24 Jul 2021 02:52:13 +0200
Subject: [PATCH 2/7] implement `std::process::Command::arg_set()`
Only unix implementation yet.
---
library/std/src/process.rs | 34 ++++++++++++++++++
library/std/src/process/tests.rs | 36 +++++++++++++++++++
.../src/sys/unix/process/process_common.rs | 7 ++++
3 files changed, 77 insertions(+)
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index 7e39952ffc44f..ac608cb0a67a4 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -680,6 +680,40 @@ impl Command {
self
}
+ /// Sets the argument at index to a new value.
+ ///
+ /// When one wants to restart a Command again with different
+ /// arguments the argument list can to be cleared first.
+ ///
+ /// # Examples
+ ///
+ /// Basic usage:
+ ///
+ /// ```no_run
+ /// #![feature(mutate_command_args)]
+ /// use std::process::Command;
+ ///
+ /// // Prepare a command
+ /// let mut command = Command::new("ls");
+ /// command.args(["-l", "-a", "FILE"]);
+ ///
+ /// // Run it with mutated 3rd parameter
+ /// ["foo", "bar", "baz"].iter()
+ /// .for_each(
+ /// |file| {
+ /// command
+ /// .arg_set(3, file)
+ /// .spawn()
+ /// .unwrap();
+ /// }
+ /// );
+ /// ```
+ #[unstable(feature = "mutate_command_args", issue = "87379")]
+ pub fn arg_set<S: AsRef<OsStr>>(&mut self, index: usize, value: S) -> &mut Command {
+ self.inner.arg_set(index, value.as_ref());
+ self
+ }
+
/// Inserts or updates an environment variable mapping.
///
/// Note that environment variable names are case-insensitive (but case-preserving) on Windows,
diff --git a/library/std/src/process/tests.rs b/library/std/src/process/tests.rs
index 838ec8a12c40a..f46b3cfc7730e 100644
--- a/library/std/src/process/tests.rs
+++ b/library/std/src/process/tests.rs
@@ -237,6 +237,42 @@ fn test_args_clear() {
assert_eq!(stderr, Vec::new());
}
+#[test]
+fn test_arg_set() {
+ let mut prog = Command::new("echo");
+
+ if cfg!(target_os = "windows") {
+ prog.args(&["/C", "echo set_me"])
+ } else {
+ prog.arg("set_me")
+ };
+
+ if cfg!(target_os = "windows") {
+ prog.arg_set(2, "echo hello");
+ } else {
+ prog.arg_set(1, "hello");
+ };
+
+ let Output { status, stdout, stderr } = prog.output().unwrap();
+ let output_str = str::from_utf8(&stdout).unwrap();
+
+ assert!(status.success());
+ assert_eq!(output_str.trim().to_string(), "hello");
+ assert_eq!(stderr, Vec::new());
+}
+
+#[test]
+#[should_panic]
+fn test_arg_set_fail() {
+ let mut prog = Command::new("echo");
+
+ if cfg!(target_os = "windows") {
+ prog.arg_set(1, "echo hello");
+ } else {
+ prog.arg_set(1, "hello");
+ };
+}
+
#[cfg(all(unix, not(target_os = "android")))]
pub fn env_cmd() -> Command {
Command::new("env")
diff --git a/library/std/src/sys/unix/process/process_common.rs b/library/std/src/sys/unix/process/process_common.rs
index daf787de0b5ff..d0568ff38eaef 100644
--- a/library/std/src/sys/unix/process/process_common.rs
+++ b/library/std/src/sys/unix/process/process_common.rs
@@ -199,6 +199,13 @@ impl Command {
self.args.truncate(1);
}
+ pub fn arg_set(&mut self, index: usize, arg: &OsStr) {
+ debug_assert!(index >= 1 && index < self.args.len(), "Index out of range");
+ let arg = os2c(arg, &mut self.saw_nul);
+ self.argv.0[index] = arg.as_ptr();
+ self.args[index] = arg;
+ }
+
pub fn cwd(&mut self, dir: &OsStr) {
self.cwd = Some(os2c(dir, &mut self.saw_nul));
}
From 6a10a48e17ed086752efd9a5c3cdeebc18d36dac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Th=C3=A4ter?= <ct@pipapo.org>
Date: Sat, 24 Jul 2021 03:07:52 +0200
Subject: [PATCH 3/7] implement `std::process::Command::args_new()`
---
library/std/src/process.rs | 42 ++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index ac608cb0a67a4..0d984203edf53 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -714,6 +714,48 @@ impl Command {
self
}
+ /// Reset the argument list to new content
+ ///
+ /// Allows to maintain the argument list in a Vec or anything else that can provide
+ /// a suitable iterator.
+ ///
+ /// # Examples
+ ///
+ /// Basic usage:
+ ///
+ /// ```no_run
+ /// #![feature(mutate_command_args)]
+ /// use std::process::Command;
+ ///
+ /// // Prepare a command
+ /// let mut command = Command::new("ls");
+ /// let mut my_args = Vec::from(["-l", "foo"]);
+ ///
+ /// command
+ /// .args_new(&my_args)
+ /// .spawn()
+ /// .unwrap();
+ ///
+ /// // Mutate my_args
+ /// my_args.insert(1, "-a");
+ /// my_args.pop();
+ /// my_args.push("bar");
+ ///
+ /// // Run command again with the mutated arguments
+ /// command
+ /// .args_new(&my_args)
+ /// .spawn()
+ /// .unwrap();
+ /// ```
+ #[unstable(feature = "mutate_command_args", issue = "87379")]
+ pub fn args_new<I, S>(&mut self, args: I) -> &mut Command
+ where
+ I: IntoIterator<Item = S>,
+ S: AsRef<OsStr>,
+ {
+ self.args_clear().args(args)
+ }
+
/// Inserts or updates an environment variable mapping.
///
/// Note that environment variable names are case-insensitive (but case-preserving) on Windows,
From 816e4ec6a569eea023fc4e70fb61095770b21810 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Th=C3=A4ter?= <ct@pipapo.org>
Date: Sat, 24 Jul 2021 03:33:21 +0200
Subject: [PATCH 4/7] FIX: assert >= 1 in process::command::arg_set()
We do not want to set argv[0] here. This needs to be asserted at any time.
Assertion for the index within range is only a debug_assert becasue its a mere
helpful error message, indexing later would assert on out of range access anyway.
---
library/std/src/sys/unix/process/process_common.rs | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/library/std/src/sys/unix/process/process_common.rs b/library/std/src/sys/unix/process/process_common.rs
index d0568ff38eaef..62e60c26e7a17 100644
--- a/library/std/src/sys/unix/process/process_common.rs
+++ b/library/std/src/sys/unix/process/process_common.rs
@@ -200,7 +200,8 @@ impl Command {
}
pub fn arg_set(&mut self, index: usize, arg: &OsStr) {
- debug_assert!(index >= 1 && index < self.args.len(), "Index out of range");
+ assert!(index >= 1, "Index must be >= 1");
+ debug_assert!(index < self.args.len(), "Index out of range");
let arg = os2c(arg, &mut self.saw_nul);
self.argv.0[index] = arg.as_ptr();
self.args[index] = arg;
From ca62a9754eb50bb5aa106b3f8dbb3b55440d2bc8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Th=C3=A4ter?= <ct@pipapo.org>
Date: Sat, 24 Jul 2021 03:36:38 +0200
Subject: [PATCH 5/7] Provide the windows implementation of args_clear() and
arg_set()
---
library/std/src/sys/windows/process.rs | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/library/std/src/sys/windows/process.rs b/library/std/src/sys/windows/process.rs
index 66b210ce1bfb3..bf3dad8d0086b 100644
--- a/library/std/src/sys/windows/process.rs
+++ b/library/std/src/sys/windows/process.rs
@@ -208,6 +208,14 @@ impl Command {
pub fn arg(&mut self, arg: &OsStr) {
self.args.push(Arg::Regular(arg.to_os_string()))
}
+ pub fn args_clear(&mut self) {
+ self.args.truncate(1);
+ }
+ pub fn arg_set(&mut self, index: usize, arg: &OsStr) {
+ assert!(index >= 1, "Index must be >= 1");
+ debug_assert!(index < self.args.len(), "Index out of range");
+ self.args[index] = Arg::Regular(arg.to_os_string());
+ }
pub fn env_mut(&mut self) -> &mut CommandEnv {
&mut self.env
}
From 9d69f08572d34d65734e3aff72f0e9babfb9d6f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Th=C3=A4ter?= <ct@pipapo.org>
Date: Sat, 24 Jul 2021 04:13:58 +0200
Subject: [PATCH 6/7] DOCFIX: arg_set() lacked doc/panics
---
library/std/src/process.rs | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index 0d984203edf53..6a9ced9d73417 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -682,8 +682,11 @@ impl Command {
/// Sets the argument at index to a new value.
///
- /// When one wants to restart a Command again with different
- /// arguments the argument list can to be cleared first.
+ /// An existing argument at the given index will be replaced with a new value.
+ ///
+ /// # Panics
+ ///
+ /// May panic if the index is 0 or out of bounds.
///
/// # Examples
///
From 45d17805195994d9471653258a86ba94a89c9a68 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Th=C3=A4ter?= <ct@pipapo.org>
Date: Sun, 24 Oct 2021 17:14:56 +0200
Subject: [PATCH 7/7] Revert "implement `std::process::Command::args_new()`"
This reverts commit 626d0e71b1e82c4804cec1a2bd03c3c53e4368ad.
* removes 'args_new()' as requested in https://github.com/rust-lang/rust/pull/87420#issuecomment-933123951
* still disallow argv0 mutation as I explained in https://github.com/rust-lang/rust/pull/87420#issuecomment-950275301
---
library/std/src/process.rs | 42 --------------------------------------
1 file changed, 42 deletions(-)
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index 6a9ced9d73417..a629a94d496a2 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -717,48 +717,6 @@ impl Command {
self
}
- /// Reset the argument list to new content
- ///
- /// Allows to maintain the argument list in a Vec or anything else that can provide
- /// a suitable iterator.
- ///
- /// # Examples
- ///
- /// Basic usage:
- ///
- /// ```no_run
- /// #![feature(mutate_command_args)]
- /// use std::process::Command;
- ///
- /// // Prepare a command
- /// let mut command = Command::new("ls");
- /// let mut my_args = Vec::from(["-l", "foo"]);
- ///
- /// command
- /// .args_new(&my_args)
- /// .spawn()
- /// .unwrap();
- ///
- /// // Mutate my_args
- /// my_args.insert(1, "-a");
- /// my_args.pop();
- /// my_args.push("bar");
- ///
- /// // Run command again with the mutated arguments
- /// command
- /// .args_new(&my_args)
- /// .spawn()
- /// .unwrap();
- /// ```
- #[unstable(feature = "mutate_command_args", issue = "87379")]
- pub fn args_new<I, S>(&mut self, args: I) -> &mut Command
- where
- I: IntoIterator<Item = S>,
- S: AsRef<OsStr>,
- {
- self.args_clear().args(args)
- }
-
/// Inserts or updates an environment variable mapping.
///
/// Note that environment variable names are case-insensitive (but case-preserving) on Windows,