test_IO

main_IO_testing.cpp

#include <iostream>
#include <fcntl.h>
#include <unistd.h>
#include <cstring>
#include <memory>

using namespace std;

int main(int argc, char* argv[]) {

    string p = "/tmp/mountdir/file"s;
    char buffIn[] = "oops.";
    char *buffOut = new char[strlen(buffIn)];

    
    /* Write the file */

    auto fd = open(p.c_str(), O_WRONLY | O_CREAT, 0777);
    if(fd < 0){
        cerr << "Error opening file" << endl;
        return -1;
    }
    auto nw = write(fd, buffIn, strlen(buffIn));
    if(nw != strlen(buffIn)){
        cerr << "Error writing file" << endl;
        return -1;
    }
    
    if(close(fd) != 0){
        cerr << "Error closing file" << endl;
        return -1;
    }


    /* Read the file back */

    fd = open(p.c_str(), O_RDONLY);
    if(fd < 0){
        cerr << "Error opening file" << endl;
        return -1;
    }

    auto nr = read(fd, buffOut, strlen(buffIn));
    if(nr != strlen(buffIn)){
        cerr << "Error reading file" << endl;
        return -1;
    }

    if(strcmp( buffIn, buffOut) != 0){
        cerr << "File content mismatch" << endl;
        return -1;
    }
    close(fd);
}