Ps: add cwd column on linux and macos (#10347)

# Description
Close:  #7484

Just found that I want `cwd` column on linux/macos as well..

crates/nu-command/src/system/ps.rs

@@ -143,6 +143,7 @@ fn run_ps(engine_state: &EngineState, call: &Call) -> Result<PipelineData, Shell
                 // record.push("tpg_id", Value::int(proc_stat.tpgid as i64, span));
                 record.push("priority", Value::int(proc_stat.priority, span));
                 record.push("process_threads", Value::int(proc_stat.num_threads, span));
+                record.push("cwd", Value::string(proc.cwd(), span));
             }
             #[cfg(windows)]
             {
@@ -184,6 +185,10 @@ fn run_ps(engine_state: &EngineState, call: &Call) -> Result<PipelineData, Shell
                     ),
                 );
             }
+            #[cfg(target_os = "macos")]
+            {
+                record.push("cwd", Value::string(proc.cwd(), span));
+            }
         }
 
         output.push(Value::record(record, span));

crates/nu-system/src/linux.rs

@@ -1,6 +1,7 @@
 use log::info;
 use procfs::process::{FDInfo, Io, Process, Stat, Status};
 use procfs::{ProcError, ProcessCgroup};
+use std::path::PathBuf;
 use std::thread;
 use std::time::{Duration, Instant};
 
@@ -70,6 +71,7 @@ pub struct ProcessInfo {
     pub prev_stat: Option<Stat>,
     pub curr_status: Option<Status>,
     pub interval: Duration,
+    pub cwd: PathBuf,
 }
 
 pub fn collect_proc(interval: Duration, _with_thread: bool) -> Vec<ProcessInfo> {
@@ -98,6 +100,7 @@ pub fn collect_proc(interval: Duration, _with_thread: bool) -> Vec<ProcessInfo>
             info!("failed to retrieve info for pid={curr_proc_pid}, process probably died between snapshots");
             continue;
         };
+        let cwd = curr_proc.cwd().unwrap_or_default();
 
         let curr_io = curr_proc.io().ok();
         let curr_stat = curr_proc.stat().ok();
@@ -117,6 +120,7 @@ pub fn collect_proc(interval: Duration, _with_thread: bool) -> Vec<ProcessInfo>
             prev_stat,
             curr_status,
             interval,
+            cwd,
         };
 
         ret.push(proc);
@@ -165,6 +169,10 @@ impl ProcessInfo {
         }
     }
 
+    pub fn cwd(&self) -> String {
+        self.cwd.display().to_string()
+    }
+
     /// Get the status of the process
     pub fn status(&self) -> String {
         if let Ok(p) = self.curr_proc.stat() {

crates/nu-system/src/macos.rs

@@ -142,6 +142,7 @@ pub struct PathInfo {
     pub root: PathBuf,
     pub cmd: Vec<String>,
     pub env: Vec<String>,
+    pub cwd: PathBuf,
 }
 
 #[cfg_attr(tarpaulin, skip)]
@@ -213,12 +214,17 @@ fn get_path_info(pid: i32, mut size: size_t) -> Option<PathInfo> {
                 }
                 start = cp;
                 let mut env = Vec::new();
+                let mut cwd = PathBuf::default();
                 while cp < ptr.add(size) {
                     if *cp == 0 {
                         if cp == start {
                             break;
                         }
-                        env.push(get_unchecked_str(cp, start));
+                        let env_str = get_unchecked_str(cp, start);
+                        if let Some(pwd) = env_str.strip_prefix("PWD=") {
+                            cwd = PathBuf::from(pwd)
+                        }
+                        env.push(env_str);
                         start = cp.offset(1);
                     }
                     cp = cp.offset(1);
@@ -238,6 +244,7 @@ fn get_path_info(pid: i32, mut size: size_t) -> Option<PathInfo> {
                     root,
                     cmd,
                     env,
+                    cwd,
                 })
             } else {
                 None
@@ -394,6 +401,13 @@ impl ProcessInfo {
     pub fn virtual_size(&self) -> u64 {
         self.curr_task.ptinfo.pti_virtual_size
     }
+
+    pub fn cwd(&self) -> String {
+        self.curr_path
+            .as_ref()
+            .map(|cur_path| cur_path.cwd.display().to_string())
+            .unwrap_or_else(|| "".to_string())
+    }
 }
 
 /// The Macos kernel returns process times in mach ticks rather than nanoseconds.  To get times in