README.md

@@ -578,6 +578,19 @@ Eclipse indexer.
 
 # Q7S Utilities
 
+## Creating files with cat and echo
+
+The only folder which can be written in the root filesystem is the `tmp` folder.
+
+You can create a simple file with initial content with `echo`
+
+```sh
+echo "Hallo Welt" > /tmp/test.txt
+cat /tmp/test.txt
+```
+
+For more useful combinations, see this [link](https://www.freecodecamp.org/news/the-cat-command-in-linux-how-to-create-a-text-file-with-cat-or-touch/).
+
 ## Libgpiod
 
 Detect all gpio device files:

bsp_q7s/boardtest/Q7STestTask.cpp

@@ -16,17 +16,20 @@ ReturnValue_t Q7STestTask::performOneShotAction() {
 void Q7STestTask::sdCardTests() {
     using namespace std;
     Stopwatch stopwatch;
-    FILE* testFile = popen("q7hw sd info all > /tmp/sd_status.txt", "r");
-    TaskFactory::delayTask(3000);
+    ofstream testFile("/tmp/test.txt");
+    testFile << "Hallo Welt" << endl;
+    testFile.close();
+    //FILE* testFile = popen("q7hw sd info all", "r");
+    //TaskFactory::delayTask(3000);
     //int result = system();
     //std::fstream fs(testFile);
     // Read contents from file
-    char* line = nullptr;
-    size_t len = 0;
-    ssize_t read = getline(&line, &len, testFile);
-    if(read != -1 and line != nullptr) {
-        cout << line << endl;
-    }
+//    char* line = nullptr;
+//    size_t len = 0;
+//    ssize_t read = getline(&line, &len, testFile);
+//    if(read != -1 and line != nullptr) {
+//        cout << line << endl;
+//    }
 //    c = fgetc(testFile);
 //    while (c != EOF)
 //    {