From 89aca1f2a06140bf556d5460963be0d213a58657 Mon Sep 17 00:00:00 2001
From: Donald Buczek <buczek@molgen.mpg.de>
Date: Wed, 15 Sep 2021 21:41:52 +0200
Subject: [PATCH] mx_proc: Add mx_proc_get_comm

Add function to get "comm"-value of a process.
---
 mx_proc.c | 24 ++++++++++++++++++++++++
 mx_proc.h |  1 +
 2 files changed, 25 insertions(+)

diff --git a/mx_proc.c b/mx_proc.c
index 129d7216..4edc2b2a 100644
--- a/mx_proc.c
+++ b/mx_proc.c
@@ -484,3 +484,27 @@ pid_t mx_proc_get_parent(pid_t pid) {
         return -1;
     return parent;
 }
+
+/*
+ * get "comm" value of a process.
+ * buf MUST point to char[16] array
+ * return NULL on any error, otherwise pointer to buf
+ */
+char *mx_proc_get_comm(pid_t pid, char *buf) {
+    char commfilename[32];  // "/proc/2147483647/comm" = 22
+    FILE *commfile;
+    char *p;
+
+    snprintf(commfilename, sizeof(commfilename), "/proc/%d/comm", pid);
+    commfile = fopen(commfilename, "r");
+    if (commfile == NULL)
+        return NULL;
+    p = fgets(buf, 16, commfile);
+    fclose(commfile);
+    if (p == NULL)
+        return NULL;
+    p = strrchr(buf, '\n');
+    if (p != NULL)
+        *p = '\0';
+    return (char *)buf;
+}
diff --git a/mx_proc.h b/mx_proc.h
index 1fe07f6f..d4abcb35 100644
--- a/mx_proc.h
+++ b/mx_proc.h
@@ -86,4 +86,5 @@ int mx_proc_tree_free(struct mx_proc_tree **tree);
 
 struct mx_proc_info *mx_proc_tree_proc_info(struct mx_proc_tree *tree, pid_t pid);
 pid_t mx_proc_get_parent(pid_t pid);
+char *mx_proc_get_comm(pid_t pid, char *buf);
 #endif