1 //! Global initialization and retrieval of command line arguments.
3 //! On some platforms these are stored during runtime startup,
4 //! and on some they are retrieved from the system on demand.
6 #![allow(dead_code)] // runtime init functions not used during testing
8 use crate::ffi::OsString;
12 /// One-time global initialization.
13 pub unsafe fn init(argc: isize, argv: *const *const u8) {
17 /// Returns the command line arguments
18 pub fn args() -> Args {
23 iter: vec::IntoIter<OsString>,
26 impl !Send for Args {}
27 impl !Sync for Args {}
29 impl fmt::Debug for Args {
30 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
31 self.iter.as_slice().fmt(f)
35 impl Iterator for Args {
37 fn next(&mut self) -> Option<OsString> {
40 fn size_hint(&self) -> (usize, Option<usize>) {
45 impl ExactSizeIterator for Args {
46 fn len(&self) -> usize {
51 impl DoubleEndedIterator for Args {
52 fn next_back(&mut self) -> Option<OsString> {
59 target_os = "android",
60 target_os = "freebsd",
61 target_os = "dragonfly",
63 target_os = "openbsd",
64 target_os = "solaris",
65 target_os = "illumos",
66 target_os = "emscripten",
69 target_os = "fuchsia",
75 use crate::ffi::{CStr, OsString};
76 use crate::os::unix::prelude::*;
78 use crate::sync::atomic::{AtomicIsize, AtomicPtr, Ordering};
80 static ARGC: AtomicIsize = AtomicIsize::new(0);
81 static ARGV: AtomicPtr<*const u8> = AtomicPtr::new(ptr::null_mut());
83 unsafe fn really_init(argc: isize, argv: *const *const u8) {
84 ARGC.store(argc, Ordering::Relaxed);
85 ARGV.store(argv as *mut _, Ordering::Relaxed);
89 pub unsafe fn init(_argc: isize, _argv: *const *const u8) {
90 // On Linux-GNU, we rely on `ARGV_INIT_ARRAY` below to initialize
91 // `ARGC` and `ARGV`. But in Miri that does not actually happen so we
92 // still initialize here.
93 #[cfg(any(miri, not(all(target_os = "linux", target_env = "gnu"))))]
94 really_init(_argc, _argv);
97 /// glibc passes argc, argv, and envp to functions in .init_array, as a non-standard extension.
98 /// This allows `std::env::args` to work even in a `cdylib`, as it does on macOS and Windows.
99 #[cfg(all(target_os = "linux", target_env = "gnu"))]
101 #[link_section = ".init_array.00099"]
102 static ARGV_INIT_ARRAY: extern "C" fn(
103 crate::os::raw::c_int,
107 extern "C" fn init_wrapper(
108 argc: crate::os::raw::c_int,
109 argv: *const *const u8,
110 _envp: *const *const u8,
113 really_init(argc as isize, argv);
119 pub fn args() -> Args {
120 Args { iter: clone().into_iter() }
123 fn clone() -> Vec<OsString> {
125 // Load ARGC and ARGV without a lock. If the store to either ARGV or
126 // ARGC isn't visible yet, we'll return an empty argument list.
127 let argv = ARGV.load(Ordering::Relaxed);
128 let argc = if argv.is_null() { 0 } else { ARGC.load(Ordering::Relaxed) };
131 let cstr = CStr::from_ptr(*argv.offset(i) as *const libc::c_char);
132 OsStringExt::from_vec(cstr.to_bytes().to_vec())
139 #[cfg(any(target_os = "macos", target_os = "ios"))]
142 use crate::ffi::CStr;
144 pub unsafe fn init(_argc: isize, _argv: *const *const u8) {}
146 #[cfg(target_os = "macos")]
147 pub fn args() -> Args {
148 use crate::os::unix::prelude::*;
150 // These functions are in crt_externs.h.
151 fn _NSGetArgc() -> *mut libc::c_int;
152 fn _NSGetArgv() -> *mut *mut *mut libc::c_char;
157 (*_NSGetArgc() as isize, *_NSGetArgv() as *const *const libc::c_char);
160 let bytes = CStr::from_ptr(*argv.offset(i)).to_bytes().to_vec();
161 OsStringExt::from_vec(bytes)
165 Args { iter: vec.into_iter() }
168 // As _NSGetArgc and _NSGetArgv aren't mentioned in iOS docs
169 // and use underscores in their names - they're most probably
170 // are considered private and therefore should be avoided
171 // Here is another way to get arguments using Objective C
174 // In general it looks like:
176 // let args = [[NSProcessInfo processInfo] arguments]
177 // for i in (0..[args count])
178 // res.push([args objectAtIndex:i])
180 #[cfg(target_os = "ios")]
181 pub fn args() -> Args {
182 use crate::ffi::OsString;
187 fn sel_registerName(name: *const libc::c_uchar) -> Sel;
188 fn objc_getClass(class_name: *const libc::c_uchar) -> NsId;
191 #[cfg(target_arch = "aarch64")]
193 fn objc_msgSend(obj: NsId, sel: Sel) -> NsId;
194 #[allow(clashing_extern_declarations)]
195 #[link_name = "objc_msgSend"]
196 fn objc_msgSend_ul(obj: NsId, sel: Sel, i: libc::c_ulong) -> NsId;
199 #[cfg(not(target_arch = "aarch64"))]
201 fn objc_msgSend(obj: NsId, sel: Sel, ...) -> NsId;
202 #[allow(clashing_extern_declarations)]
203 #[link_name = "objc_msgSend"]
204 fn objc_msgSend_ul(obj: NsId, sel: Sel, ...) -> NsId;
207 type Sel = *const libc::c_void;
208 type NsId = *const libc::c_void;
210 let mut res = Vec::new();
213 let process_info_sel = sel_registerName("processInfo\0".as_ptr());
214 let arguments_sel = sel_registerName("arguments\0".as_ptr());
215 let utf8_sel = sel_registerName("UTF8String\0".as_ptr());
216 let count_sel = sel_registerName("count\0".as_ptr());
217 let object_at_sel = sel_registerName("objectAtIndex:\0".as_ptr());
219 let klass = objc_getClass("NSProcessInfo\0".as_ptr());
220 let info = objc_msgSend(klass, process_info_sel);
221 let args = objc_msgSend(info, arguments_sel);
223 let cnt: usize = mem::transmute(objc_msgSend(args, count_sel));
225 let tmp = objc_msgSend_ul(args, object_at_sel, i as libc::c_ulong);
226 let utf_c_str: *const libc::c_char = mem::transmute(objc_msgSend(tmp, utf8_sel));
227 let bytes = CStr::from_ptr(utf_c_str).to_bytes();
228 res.push(OsString::from(str::from_utf8(bytes).unwrap()))
232 Args { iter: res.into_iter() }