Fix #97

src/slurm.rs

@@ -1,9 +1,11 @@
 // Abstraction of jobs::JobManager for SLURM.
 
-use crate::command;
 use crate::jobs;
 use crate::process;
 
+use std::fs::File;
+use std::io::{BufRead,BufReader};
+
 pub struct SlurmJobManager {}
 
 impl jobs::JobManager for SlurmJobManager {
@@ -14,21 +16,31 @@ impl jobs::JobManager for SlurmJobManager {
 }
 
 fn get_slurm_job_id(pid: usize) -> Option<String> {
-    let path = format!("/proc/{}/cgroup", pid);
-
-    if !std::path::Path::new(&path).exists() {
-        return None;
-    }
+    match File::open(format!("/proc/{pid}/cgroup")) {
+        Ok(f) => {
 
-    let command = format!(
-        "cat /proc/{}/cgroup | grep -oP '(?<=job_).*?(?=/)' | head -n 1",
-        pid
-    );
-    let timeout_seconds = 2;
+            // We want \1 of the first line that matches "/job_(.*?)/"
+            //
+            // The reason is that there are several lines in that file that look roughly like this,
+            // with different contents (except for the job info) but with the pattern the same:
+            //
+            //    10:devices:/slurm/uid_2101171/job_280678/step_interactive/task_0
 
-    // TODO: Maybe propagate an error here?
-    match command::safe_command(&command, timeout_seconds) {
-        Ok(s) => Some(s),
-        Err(_) => None,
+            for l in BufReader::new(f).lines() {
+                if let Ok(l) = l {
+                    if let Some(x) = l.find("/job_") {
+                        if let Some(y) = l[x+5..].find('/') {
+                            return Some(l[x+5..x+5+y].to_string())
+                        }
+                    }
+                } else {
+                    return None;
+                }
+            }
+            return None;
+        }
+        Err(_) => {
+            return None;
+        }
     }
 }