Handle parsing envID & VPid from process status file

Fixes #55
Fixes #192

linux/LinuxProcess.c

@@ -77,8 +77,8 @@ ProcessFieldData Process_fields[] = {
    [NLWP] = { .name = "NLWP", .title = "NLWP ", .description = "Number of threads in the process", .flags = 0, },
    [TGID] = { .name = "TGID", .title = "   TGID ", .description = "Thread group ID (i.e. process ID)", .flags = 0, },
 #ifdef HAVE_OPENVZ
-   [CTID] = { .name = "CTID", .title = "   CTID ", .description = "OpenVZ container ID (a.k.a. virtual environment ID)", .flags = PROCESS_FLAG_LINUX_OPENVZ, },
-   [VPID] = { .name = "VPID", .title = " VPID ", .description = "OpenVZ process ID", .flags = PROCESS_FLAG_LINUX_OPENVZ, },
+   [CTID] = { .name = "CTID", .title = " CTID    ", .description = "OpenVZ container ID (a.k.a. virtual environment ID)", .flags = PROCESS_FLAG_LINUX_OPENVZ, },
+   [VPID] = { .name = "VPID", .title = "    VPID ", .description = "OpenVZ process ID", .flags = PROCESS_FLAG_LINUX_OPENVZ, },
 #endif
 #ifdef HAVE_VSERVER
    [VXID] = { .name = "VXID", .title = " VXID ", .description = "VServer process ID", .flags = PROCESS_FLAG_LINUX_VSERVER, },
@@ -148,6 +148,9 @@ void Process_delete(Object* cast) {
    Process_done((Process*)cast);
 #ifdef HAVE_CGROUP
    free(this->cgroup);
+#endif
+#ifdef HAVE_OPENVZ
+   free(this->ctid);
 #endif
    free(this->secattr);
    free(this->ttyDevice);
@@ -253,7 +256,7 @@ void LinuxProcess_writeField(Process* this, RichString* str, ProcessField field)
    }
    #endif
    #ifdef HAVE_OPENVZ
-   case CTID: xSnprintf(buffer, n, "%7u ", lp->ctid); break;
+   case CTID: xSnprintf(buffer, n, "%-8s ", lp->ctid ? lp->ctid : ""); break;
    case VPID: xSnprintf(buffer, n, Process_pidFormat, lp->vpid); break;
    #endif
    #ifdef HAVE_VSERVER
@@ -351,7 +354,7 @@ long LinuxProcess_compare(const void* v1, const void* v2) {
    #endif
    #ifdef HAVE_OPENVZ
    case CTID:
-      return (p2->ctid - p1->ctid);
+      return strcmp(p1->ctid ? p1->ctid : "", p2->ctid ? p2->ctid : "");
    case VPID:
       return (p2->vpid - p1->vpid);
    #endif

linux/LinuxProcess.h

@@ -122,8 +122,8 @@ typedef struct LinuxProcess_ {
    double io_rate_write_bps;
    #endif
    #ifdef HAVE_OPENVZ
-   unsigned int ctid;
-   unsigned int vpid;
+   char* ctid;
+   pid_t vpid;
    #endif
    #ifdef HAVE_VSERVER
    unsigned int vxid;

linux/LinuxProcessList.c

@@ -482,25 +482,94 @@ static bool LinuxProcessList_readSmapsFile(LinuxProcess* process, const char* di
 
 static void LinuxProcessList_readOpenVZData(LinuxProcess* process, const char* dirname, const char* name) {
    if ( (access(PROCDIR "/vz", R_OK) != 0)) {
+      free(process->ctid);
+      process->ctid = NULL;
       process->vpid = process->super.pid;
-      process->ctid = 0;
       return;
    }
+
    char filename[MAX_NAME+1];
-   xSnprintf(filename, MAX_NAME, "%s/%s/stat", dirname, name);
+   xSnprintf(filename, sizeof(filename), "%s/%s/status", dirname, name);
    FILE* file = fopen(filename, "r");
-   if (!file)
+   if (!file) {
+      free(process->ctid);
+      process->ctid = NULL;
+      process->vpid = process->super.pid;
       return;
-   (void)! fscanf(file,
-      "%*32u %*32s %*1c %*32u %*32u %*32u %*32u %*32u %*32u %*32u "
-      "%*32u %*32u %*32u %*32u %*32u %*32u %*32u %*32u "
-      "%*32u %*32u %*32u %*32u %*32u %*32u %*32u %*32u "
-      "%*32u %*32u %*32u %*32u %*32u %*32u %*32u %*32u "
-      "%*32u %*32u %*32u %*32u %*32u %*32u %*32u %*32u "
-      "%*32u %*32u %*32u %*32u %*32u %*32u %*32u "
-      "%*32u %*32u %32u %32u",
-      &process->vpid, &process->ctid);
+   }
+
+   bool foundEnvID = false;
+   bool foundVPid = false;
+   char linebuf[256];
+   while(fgets(linebuf, sizeof(linebuf), file) != NULL) {
+      if(strchr(linebuf, '\n') == NULL) {
+         // Partial line, skip to end of this line
+         while(fgets(linebuf, sizeof(linebuf), file) != NULL) {
+            if(strchr(linebuf, '\n') != NULL) {
+               break;
+            }
+         }
+         continue;
+      }
+
+      char* name_value_sep = strchr(linebuf, ':');
+      if(name_value_sep == NULL) {
+         continue;
+      }
+
+      int field;
+      if(0 == strncasecmp(linebuf, "envID", name_value_sep - linebuf)) {
+         field = 1;
+      } else if(0 == strncasecmp(linebuf, "VPid", name_value_sep - linebuf)) {
+         field = 2;
+      } else {
+         continue;
+      }
+
+      do {
+         name_value_sep++;
+      } while(*name_value_sep != '\0' && *name_value_sep <= 32);
+
+      char* value_end = name_value_sep;
+
+      while(*value_end != '\0' && *value_end > 32) {
+         value_end++;
+      }
+
+      if(name_value_sep == value_end) {
+         continue;
+      }
+
+      *value_end = '\0';
+
+      switch(field) {
+      case 1:
+         foundEnvID = true;
+         if(0 != strcmp(name_value_sep, process->ctid ? process->ctid : "")) {
+            free(process->ctid);
+            process->ctid = xStrdup(name_value_sep);
+         }
+         break;
+      case 2:
+         foundVPid = true;
+         process->vpid = strtoul(name_value_sep, NULL, 0);
+         break;
+      default:
+         //Sanity Check: Should never reach here, or the implementation is missing something!
+         assert(false && "OpenVZ handling: Unimplemented case for field handling reached.");
+      }
+   }
+
    fclose(file);
+
+   if(!foundEnvID) {
+      free(process->ctid);
+      process->ctid = NULL;
+   }
+
+   if(!foundVPid) {
+      process->vpid = process->super.pid;
+   }
 }
 
 #endif