Fail gracefully when /proc is not mounted

(thanks to Philipp Hagemeister)

CRT.c

@@ -11,8 +11,10 @@ in the source distribution for its full text.
 #include "String.h"
 
 #include <curses.h>
+#include <errno.h>
 #include <signal.h>
 #include <stdlib.h>
+#include <string.h>
 #ifdef HAVE_EXECINFO_H
 #include <execinfo.h>
 #endif
@@ -198,6 +200,13 @@ void CRT_done() {
    endwin();
 }
 
+void CRT_fatalError(const char* note) {
+   char* sysMsg = strerror(errno);
+   CRT_done();
+   fprintf(stderr, "%s: %s\n", note, sysMsg);
+   exit(2);
+}
+
 int CRT_readKey() {
    nocbreak();
    cbreak();

CRT.h

@@ -119,6 +119,8 @@ void CRT_init(int delay, int colorScheme);
 
 void CRT_done();
 
+void CRT_fatalError(const char* note);
+
 int CRT_readKey();
 
 void CRT_disableDelay();

ChangeLog

@@ -3,6 +3,8 @@ What's new in version 1.0.2
 
 * Add IO priority support ('i' key)
 * Avoid deleting .htoprc if it is a symlink
+* Fail gracefully when /proc is not mounted
+  (thanks to Philipp Hagemeister)
 * BUGFIX: Fix crashes when process list is empty
 
 What's new in version 1.0.1

ProcessList.c

@@ -193,7 +193,9 @@ ProcessList* ProcessList_new(UsersTable* usersTable, Hashtable* pidWhiteList) {
    this->processes2 = Vector_new(PROCESS_CLASS, true, DEFAULT_SIZE, Process_compare);
    
    FILE* file = fopen(PROCSTATFILE, "r");
-   assert(file != NULL);
+   if (file == NULL) {
+      CRT_fatalError("Cannot open " PROCSTATFILE);
+   }
    char buffer[256];
    int cpus = -1;
    do {
@@ -758,7 +760,9 @@ void ProcessList_scan(ProcessList* this) {
    unsigned long long int swapFree = 0;
 
    FILE* file = fopen(PROCMEMINFOFILE, "r");
-   assert(file != NULL);
+   if (file == NULL) {
+      CRT_fatalError("Cannot open " PROCMEMINFOFILE);
+   }
    int cpus = this->cpuCount;
    {
       char buffer[128];
@@ -796,7 +800,9 @@ void ProcessList_scan(ProcessList* this) {
    fclose(file);
 
    file = fopen(PROCSTATFILE, "r");
-   assert(file != NULL);
+   if (file == NULL) {
+      CRT_fatalError("Cannot open " PROCSTATFILE);
+   }
    for (int i = 0; i <= cpus; i++) {
       char buffer[256];
       int cpuid;