while executing external command, make it as foreground

crates/nu-system/Cargo.toml

@@ -13,7 +13,7 @@ name = "ps"
 path = "src/main.rs"
 
 [dependencies]
-
+libc = "0.2"
 
 [target.'cfg(any(target_os = "linux", target_os = "android"))'.dependencies]
 procfs  = "0.13.0"
@@ -21,11 +21,9 @@ procfs  = "0.13.0"
 [target.'cfg(target_os = "macos")'.dependencies]
 libproc = "0.12.0"
 errno = "0.2"
-libc = "0.2"
 
 [target.'cfg(target_os = "windows")'.dependencies]
 winapi = { version = "0.3.9", features = ["tlhelp32", "fileapi", "handleapi", "ifdef", "ioapiset", "minwindef", "pdh", "psapi", "synchapi", "sysinfoapi", "winbase", "winerror", "winioctl", "winnt", "oleauto", "wbemcli", "rpcdce", "combaseapi", "objidl", "powerbase", "netioapi", "lmcons", "lmaccess", "lmapibuf", "memoryapi", "shellapi", "std", "securitybaseapi"] }
 chrono = "0.4"
-libc = "0.2"
 ntapi = "0.3"
 once_cell = "1.0"

crates/nu-system/src/foreground.rs

@@ -0,0 +1,45 @@
+// It's a simpler version for fish shell's external process handling.
+//
+// For more information, please check `child_setup_process` function in fish shell.
+// https://github.com/fish-shell/fish-shell/blob/3f90efca38079922b4b21707001d7bb9630107eb/src/postfork.cpp#L140
+#[cfg(target_family = "unix")]
+pub mod external_process_setup {
+    use std::os::unix::prelude::CommandExt;
+    pub fn setup_fg_external(external_command: &mut std::process::Command) {
+        unsafe {
+            libc::signal(libc::SIGTTOU, libc::SIG_IGN);
+            libc::signal(libc::SIGTTIN, libc::SIG_IGN);
+
+            external_command.pre_exec(|| {
+                libc::setpgid(0, 0);
+                Ok(())
+            });
+        }
+    }
+
+    pub fn set_foreground(process: &std::process::Child) -> i32 {
+        unsafe {
+            let my_id = libc::getpid();
+            libc::tcsetpgrp(0, process.id() as i32);
+            my_id
+        }
+    }
+
+    pub fn reset_foreground_id() {
+        unsafe {
+            libc::tcsetpgrp(libc::STDIN_FILENO, libc::getpgrp());
+            libc::signal(libc::SIGTTOU, libc::SIG_DFL);
+            libc::signal(libc::SIGTTIN, libc::SIG_DFL);
+        }
+    }
+}
+
+#[cfg(target_family = "windows")]
+mod external_process_setup {
+
+    pub fn setup_fg_external(external_command: &mut std::process::Command) {}
+
+    pub fn set_foreground(process: &std::process::Child) -> i32 {}
+
+    pub fn reset_foreground_id() {}
+}

crates/nu-system/src/lib.rs

@@ -4,6 +4,7 @@ mod linux;
 mod macos;
 #[cfg(target_os = "windows")]
 mod windows;
+mod foreground;
 
 #[cfg(any(target_os = "android", target_os = "linux"))]
 pub use self::linux::*;
@@ -11,3 +12,4 @@ pub use self::linux::*;
 pub use self::macos::*;
 #[cfg(target_os = "windows")]
 pub use self::windows::*;
+pub use self::foreground::external_process_setup;