function_set.h

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//============================================================================
// Name        : function_set.h
// Author      : Konstantin Gertsenberger (gertsen@jinr.ru)
// Description : set of common C++ functions
// Version     : 1.11
//============================================================================
#ifndef FUNCTION_SET_H
#define FUNCTION_SET_H
 
// C++ includes
#include <unistd.h>
#include <iomanip>
#include <iostream>
#include <cstring>
#include <string>
#include <stdlib.h>
#include <stdio.h>
#include <sstream>
#include <ctime>
#include <math.h>
#include <memory>
#include <limits.h>
#include <sys/stat.h>
 
using namespace std;
 
/* declarations */
enum BATCH_SYSTEM_NAME {SGE_BATCH_SYSTEM, TORQUE_BATCH_SYSTEM, SLURM_BATCH_SYSTEM}; // 'get_batch_processor_count' function
 
/* OS FUNCTIONS */
// execute system command in shell (bash)
int system_command_linux(string aCommand, string& result);
// replace all Linux environment variables and tilde in a specified path (input argument)
string expand_path(string path);
// get absolute path with replacing environment variables using Linux shell
string absolute_path(string path);
// get processor core count on this machine
int get_linux_processor_count();
// get maximum available processor count on Sun Grid Engine system
int get_batch_processor_count(BATCH_SYSTEM_NAME batch_system, string queue_name = "");
 
/* GLOBAL APPLICATION FUNCTIONS */
// get application name in linux
string get_app_name_linux();
// get aplication directory (path without file name) in linux
string get_app_dir_linux();
 
/* NUMBER FUNCTIONS */
// check bit in 'variable' at 'position'
#define CHECK_BIT(variable,position) ((variable) & (1ULL<<(position)))
 
/* STRING FUNCTIONS */
// return string according to the given format and arguments (as for snprintf function)
template<typename ... Args>
string string_format(const string& format, Args ... args);
// convert double number to string with a given precision
// is_fixed_point: true - {precision = number of decimal digits after point}; false - {precision = number of all decimal digits in the number}
string double_to_string(double number, int precision, bool is_fixed_point = true);
// convert integer number to string
string int_to_string(int number);
// convert integer (hexadecimal value) to string with hexadecimal presentation without "0x"
string int_to_hex_string(int number);
// convert string with hexadecimal presentation without "0x" to integer
int hex_string_to_int(string hex_string);
// convert string specified size in bytes to double value; "convert_to" - possible values "BKMGTP"
double byte_size_to_double(string byte_size_in_string, char convert_to = 'B');
// convert string specified size in bytes to human-readable format
string byte_size_to_human(uint64_t byte_size, unsigned precision = 2);
// is string an integer number?
bool is_string_number(const string& s);
// extract first number or last number in string, only positive number by default (result number has string type)
string find_first_number(string const &str, bool isOnlyPositive = true);   string find_first_double_number(string const &str, bool isOnlyPositive = true);
string find_last_number(string const &str, bool isOnlyPositive = true);    string find_last_double_number(string const &str, bool isOnlyPositive = true);
// extract first number or last number in string, only positive number by default (result number has string type)
// beg_pos - position of the first character in the string to be assigned before the search for find_first...; returns position of number (string::npos, if not found)
// end_pos - position of the last character in the string to be assigned before the search for find_last...; returns position of number (string::npos, if not found)
string find_first_number(string const &str, size_t &beg_pos, size_t &end_pos, bool isOnlyPositive = true); string find_first_double_number(string const &str, size_t &beg_pos, size_t &end_pos, bool isOnlyPositive = true);
string find_last_number(string const &str, size_t &beg_pos, size_t &end_pos, bool isOnlyPositive = true);  string find_last_double_number(string const &str, size_t &beg_pos, size_t &end_pos, bool isOnlyPositive = true);
// convert array of chars to the new lowercase array
char* convert_pchar_to_lowercase_new(char* input_char_array);
// replace string 'old_substring' by string 'new_substring' in 'text'
void replace_string_in_text(string &text, string old_substring, string new_substring);
// replace string 'old_substring' by integer 'new_subinteger' in 'text'
void replace_string_in_text(string &text, string old_substring, int new_subinteger);
// replace char 'find' in array of characters (char*) by another char 'replace'; return number of replacement
int replace_char(char*& str, char find, char replace);
// return string without leading and trailing spaces and tabs
string trim(const string& str, const string& whitespace = " \t\r");
// return string changing whitespaces and tabs by single whitespace
string reduce(const string& str, const string& fill = " ", const string& whitespace = " \t\r");
// is string ('full_str') ending with the given substring ('ending')
bool endswith(string const &full_str, string const &ending);
 
/*   DIR & FILE FUNCTIONS   */
// check directory exists: 0 - not exists, 1 - exists, -2 - cannot access
int check_directory_exist(const char* path);
// check and create directory if not exists: 0 - not existed before, 1 - existed, -1 - errno error, -2 - cannot access
int create_directory(const char* path);
// check and create all non-existent directories in the path:
// 0 - not existed before, 1 - existed, 2 - not required, -1 - errno error, -2 - cannot access
int create_directory_tree(const char* path);
// get file name without extension from a path
string get_file_name(string path);
// get file name with extension from path
string get_file_name_with_ext(string path);
// get directory path without last slash from file path
string get_directory_path(string file_path);
// get directory name from file path
string get_directory_name(string file_path);
 
/*  TIME FUNCTIONS  */
// get current date as string
string get_current_date();
// convert string in a given format to datetime struct tm
tm convert_string_to_datetime(string str_datetime, const char* format = "%d.%m.%Y %H:%M:%S");
// convert time in double (fractional number of seconds) to a timespec
struct timespec convert_double_to_timespec(double sec);
 
 
#ifndef ONLY_DECLARATIONS
 
/*              */
/*              */
/* OS FUNCTIONS */
/*              */
/*              */
 
// execute system command in shell (bash) and return output in 'result' (maximum = 4096 chars)
int system_command_linux(string aCommand, string& result)
{
    FILE* f;
    if ((f = popen(aCommand.c_str(), "r")) == nullptr)
    {
      cout<<"system_command_linux error: popen failed"<<endl;
        return errno;
    }
 
    const int BUFSIZE = 4096;
    char buf[BUFSIZE];
    if (fgets(buf, BUFSIZE, f) != nullptr)
        result = buf;
    else
    {
        pclose(f);
        return errno;
    }
 
    pclose(f);
    return 0;
}
 
// replace all Linux environment variables and tilde in a specified path (input argument)
string expand_path(string path)
{
    size_t find_result = path.find('$');
    if (find_result != string::npos)
    {
        string pre  = path.substr(0, find_result);
        bool is_brace = false;
        if (path[find_result] == '{')
        {
            is_brace = true;
            find_result++;
        }
        string post = path.substr(find_result+1);
 
        if (is_brace) find_result = post.find('}');
        else find_result = post.find('/');
        if ((find_result != string::npos) || (!is_brace))
        {
            string variable = post.substr(0, find_result);
            string value    = "";
 
            if (is_brace) find_result++;
            post = post.substr(find_result);
 
            const char* v = getenv(variable.c_str());
            if (v != NULL) value = string(v);
 
            return expand_path(pre + value + post);
        }
    }
 
    find_result = path.find('~');
    if (find_result != string::npos)
    {
        string value = "";
        const char* v = getenv("HOME");
        if (v != NULL) value = string(v);
 
        do
        {
            path.replace(find_result, 1, value);
            find_result = path.find('~');
        } while (find_result != string::npos);
    }
 
    return path;
}
 
// get absolute path with replacing environment variables using Linux shell
string absolute_path(string path)
{
    // check sudo injections
    size_t find_result = path.find("sudo");
    if (find_result != string::npos)
        if ((path[find_result+4] == ' ') || (path[find_result+4] == '\t'))
            return path;
 
    string aCommand, result;
    aCommand = string_format("echo \"$(cd \"$(dirname \"%s\")\" 2>/dev/null; pwd)/$(basename \"%s\")\" 2>/dev/null", path.c_str(), path.c_str());
    if (system_command_linux(aCommand, result) != 0) result = path;
 
    return result;
}
 
// get processor core count on this machine
int get_linux_processor_count()
{
    return sysconf(_SC_NPROCESSORS_ONLN);
}
 
// get maximum available processor count of the batch system for the given (default) queue
int get_batch_processor_count(BATCH_SYSTEM_NAME batch_system, string queue_name)
{
    int proc_count = 0;
 
    const int MAX_BUFFER = 255;
    char buffer[MAX_BUFFER];
    string command_line, data, strDiff;
 
    //define shell command to get string with processor count for the queue
    if (batch_system == SGE_BATCH_SYSTEM)
    {
      if (queue_name == "")
        queue_name = "all.q";
      command_line = string("export SGE_SINGLE_LINE=1; qconf -sq ") + queue_name + string(" | grep slots");
    }
    if (batch_system == TORQUE_BATCH_SYSTEM)
    {
      if (queue_name == "")
          queue_name = "batch";
        command_line = string("qstat -f -Q ") + queue_name + string(" | grep max_running");
    }
    if (batch_system == SLURM_BATCH_SYSTEM)
    {
      if (queue_name == "")
        queue_name = "interactive";
      command_line = string("scontrol show partition ") + queue_name + string(" | grep -o 'TotalCPUs=[0-9]*'");
    }
 
    // run shell command to define batch processor count
    FILE* stream = popen(command_line.c_str(), "r");
    while (fgets(buffer, MAX_BUFFER, stream) != nullptr)
      data.append(buffer);
    pclose(stream);
 
    // parse result string to extract processor count
    size_t found = data.find("="), found2 = string::npos;
    if (batch_system == SGE_BATCH_SYSTEM)
    {
      while (found != string::npos)
        {
        found2 = data.find("]", found);
          strDiff = data.substr(found+1, found2 - found - 1);
          proc_count += atoi(strDiff.c_str());
          strDiff.clear();
 
          found = data.find("=", found2);
        }
    }
    if (batch_system == TORQUE_BATCH_SYSTEM)
    {
      if (found != string::npos)
        {
        strDiff = data.substr(found+1, data.length() - found - 1);
        proc_count = atoi(strDiff.c_str());
        }
    }
    if (batch_system == SLURM_BATCH_SYSTEM)
    {
      if (found != string::npos)
        {
          strDiff = data.substr(found+1, data.length() - found - 1);
          proc_count = atoi(strDiff.c_str());
        }
    }
 
  data.clear();
    //cout<<"Batch processor count: "<<proc_count<<endl;
    return proc_count;
}
 
 
/*                              */
/*        */
/* GLOBAL APPLICATION FUNCTIONS */
/*        */
/*                              */
 
// get application name in linux
string get_app_name_linux()
{
    pid_t procpid = getpid();
    stringstream toCom;
    toCom << "cat /proc/" << procpid << "/comm";
    string fRes="";
    system_command_linux(toCom.str(), fRes);
    size_t last_pos = fRes.find_last_not_of(" \n\r\t") + 1;
    if (last_pos != string::npos)
        fRes.erase(last_pos);
 
    return fRes;
}
 
// get aplication directory (path without file name) in linux
string get_app_dir_linux()
{
    pid_t procpid = getpid();
    string appName = get_app_name_linux();
    stringstream command;
    command <<  "readlink /proc/" << procpid << "/exe | sed \"s/\\(\\/" << appName << "\\)$//\"";
    string fRes;
    system_command_linux(command.str(),fRes);
 
    // remove '\n' from end of the string and add final '/'
    fRes = fRes.erase(fRes.length()-1, 1);
    fRes.push_back('/');
 
    return fRes;
}
 
 
/*                  */
/*                  */
/* NUMBER FUNCTIONS */
/*                  */
/*                  */
 
 
 
/*                  */
/*                  */
/* STRING FUNCTIONS */
/*                  */
/*                  */
 
// return string according to the given format and arguments (as for snprintf function)
template<typename ... Args>
string string_format(const string& format, Args ... args)
{
    int size_s = snprintf(nullptr, 0, format.c_str(), args ...) + 1;
    if (size_s <= 0) throw runtime_error("Error during formatting.");
    auto size = static_cast<size_t>(size_s);
    unique_ptr<char[]> buf(new char[size]);
    snprintf(buf.get(), size, format.c_str(), args ...);
    return string(buf.get(), buf.get() + size - 1);
}
 
// convert double number to string with a given precision
// is_fixed_point: true - {precision = number of decimal digits after point}; false - {precision = number of all decimal digits in the number}
string double_to_string(double number, int precision, bool is_fixed_point)
{
  stringstream stream;
  if (is_fixed_point) stream << std::fixed;
  stream << std::setprecision(precision) << number;
  return stream.str();
}
 
// convert integer number to string
string int_to_string(int number)
{
    stringstream ss;
    ss<<number;
    return ss.str();
}
 
// convert integer (hexadecimal value) to string with hexadecimal presentation without "0x"
string int_to_hex_string(int number)
{
    stringstream stream;
    stream<<std::hex<<number;
    return stream.str();
}
 
// convert string with hexadecimal presentation without "0x" to integer
int hex_string_to_int(string hex_string)
{
    int x;
    stringstream stream;
    stream<<std::hex<<hex_string;
    stream>>x;
    return x;
}
 
// convert string specified size in bytes to double value; "convert_to" - possible values "BKMGTP"
// return byte size in double or code error if negative
double byte_size_to_double(string byte_size_in_string, char convert_to)
{
    if (byte_size_in_string.empty()) return -1; // empty string
 
    // remove spaces
    replace_string_in_text(byte_size_in_string, " ", "");
    // find text
    size_t indText = byte_size_in_string.find_first_not_of("0123456789,.");
    if (indText == 0) return -2;  // no number at the beginning
 
    string units = "BKMGTP";
 
    size_t convert_dim = units.find(::toupper(convert_to)), value_dim = -1;
    if (convert_dim == string::npos) convert_dim = 0;
 
    double number = -3;
    if (indText == string::npos)
    {
      number = atof(byte_size_in_string.c_str());
      value_dim = 0;
    }
    else
    {
      number = atof(byte_size_in_string.substr(0, indText).c_str());
      value_dim = units.find(::toupper(byte_size_in_string[indText]));
      if (value_dim == string::npos) value_dim = 0;
    }
 
    if (convert_dim != value_dim)
      number *= pow(1024, value_dim - convert_dim);
 
    return number;
}
 
// convert string specified size in bytes to human-readable format
string byte_size_to_human(uint64_t byte_size, unsigned precision)
{
    constexpr const char FILE_SIZE_UNITS[8][3]{
            "B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB"
    };
 
    // LOGARITHMIC METHOD
    if (byte_size == 0)
        return "0 B";
    else
    {
        int order = floor(log(byte_size) / log(1024));
        float num = ((float) byte_size) / pow(1024, order);
        return string_format("%.*f %s", precision, num, FILE_SIZE_UNITS[order]);
    }
}
 
// is string an integer number?
bool is_string_number(const string& s)
{
    string::const_iterator it = s.begin();
    while (it != s.end() && std::isdigit(*it)) ++it;
    return !s.empty() && it == s.end();
}
 
// 8 following functions: extract first number or last number in string, only positive number by default (result number has string type)
string find_first_number(string const &str, bool isOnlyPositive)
{
    size_t n = str.find_first_of("0123456789");
    if (n != string::npos)
    {
        size_t m = str.find_first_not_of("0123456789", n);
        if ((!isOnlyPositive) && (n > 0) && ((str[n-1] == '+') || (str[n-1] == '-')))
            n--;
        return str.substr(n, m != string::npos ? m-n : m);
    }
 
    return string();
}
 
string find_last_number(string const &str, bool isOnlyPositive)
{
    size_t n = str.find_last_of("0123456789");
    if (n != string::npos)
    {
        string temp = str.substr(0, n+1);
        size_t m = temp.find_last_not_of("0123456789");
        if (m != string::npos)
        {
            if ((!isOnlyPositive) && ((str[m] == '+') || (str[m] == '-')))
                m--;
            return temp.substr(m+1, n-m);
        }
        return temp;
    }
 
    return string();
}
 
string find_first_double_number(string const &str, bool isOnlyPositive)
{
    size_t n = str.find_first_of("0123456789");
    if (n != string::npos)
    {
        size_t m = str.find_first_not_of("0123456789,.", n);
        if ((!isOnlyPositive) && (n > 0) && ((str[n-1] == '+') || (str[n-1] == '-')))
            n--;
        return str.substr(n, m != string::npos ? m-n : m);
    }
 
    return string();
}
 
string find_last_double_number(string const &str, bool isOnlyPositive)
{
    size_t n = str.find_last_of("0123456789");
    if (n != string::npos)
    {
        string temp = str.substr(0, n+1);
        size_t m = temp.find_last_not_of("0123456789,.");
        if (m != string::npos)
        {
            if ((!isOnlyPositive) && ((str[m] == '+') || (str[m] == '-')))
                m--;
            return temp.substr(m+1, n-m);
        }
        return temp;
    }
 
    return string();
}
 
string find_first_number(string const &str, size_t &beg_pos, size_t &end_pos, bool isOnlyPositive)
{
    beg_pos = str.find_first_of("0123456789", beg_pos);
    if (beg_pos != string::npos)
    {
        size_t m = str.find_first_not_of("0123456789", beg_pos);
        end_pos = (m != string::npos ? m-1 : str.length()-1);
        if ((!isOnlyPositive) && (beg_pos > 0) && ((str[beg_pos-1] == '+') || (str[beg_pos-1] == '-')))
            beg_pos--;
        return str.substr(beg_pos, m != string::npos ? m-beg_pos : m);
    }
 
    end_pos = string::npos;
    return string();
}
 
string find_last_number(string const &str, size_t &beg_pos, size_t &end_pos, bool isOnlyPositive)
{
    end_pos = str.find_last_of("0123456789", end_pos);
    if (end_pos != string::npos)
    {
        string temp = str.substr(0, end_pos + 1);
        size_t m = temp.find_last_not_of("0123456789");
        beg_pos = (m != string::npos ? m+1 : 0);
        if (m != string::npos)
        {
            if ((!isOnlyPositive) && ((str[m] == '+') || (str[m] == '-')))
                beg_pos--;
            return temp.substr(beg_pos, end_pos-beg_pos+1);
        }
        return temp;
    }
 
    beg_pos = string::npos;
    return string();
}
 
string find_first_double_number(string const &str, size_t &beg_pos, size_t &end_pos, bool isOnlyPositive)
{
    beg_pos = str.find_first_of("0123456789", beg_pos);
    if (beg_pos != string::npos)
    {
        size_t m = str.find_first_not_of("0123456789,.", beg_pos);
        end_pos = (m != string::npos ? m-1 : str.length()-1);
        if ((!isOnlyPositive) && (beg_pos > 0) && ((str[beg_pos-1] == '+') || (str[beg_pos-1] == '-')))
            beg_pos--;
        return str.substr(beg_pos, m != string::npos ? m-beg_pos : m);
    }
 
    end_pos = string::npos;
    return string();
}
 
string find_last_double_number(string const &str, size_t &beg_pos, size_t &end_pos, bool isOnlyPositive)
{
    end_pos = str.find_last_of("0123456789", end_pos);
    if (end_pos != string::npos)
    {
        string temp = str.substr(0, end_pos+1);
        size_t m = temp.find_last_not_of("0123456789,.");
        beg_pos = (m != string::npos ? m+1 : 0);
        if (m != string::npos)
        {
            if ((!isOnlyPositive) && ((str[m] == '+') || (str[m] == '-')))
                beg_pos--;
            return temp.substr(beg_pos, end_pos-beg_pos+1);
        }
        return temp;
    }
 
    beg_pos = string::npos;
    return string();
}
 
// convert array of chars to the new lowercase array
char* convert_pchar_to_lowercase_new(char* input_char_array)
{
    if (input_char_array == nullptr)
        return nullptr;
 
    const int length = strlen(input_char_array);  // get the length of the text
    char* lower = new char[length + 1];   // allocate 'length' bytes + 1 (for null terminator) and cast to char*
    lower[length] = 0;            // set the last byte to a null terminator
 
    // copy all character bytes to the new buffer using tolower
    for( int i = 0; i < length; i++ )
        lower[i] = tolower(input_char_array[i]);
 
 
    return lower;
}
 
// replace string 'old_substring' by string 'new_substring' in 'text'
void replace_string_in_text(string &text, string old_substring, string new_substring)
{
    int start = -1;
    do
    {
        start = text.find(old_substring, start + 1);
        if (start > -1)
        {
            text.replace(start, old_substring.length(), new_substring.c_str());
            start += new_substring.length() - old_substring.length();
        }
    }
    while (start > -1);
}
 
// replace string 'old_substring' by integer 'new_subinteger' in 'text'
void replace_string_in_text(string &text, string old_substring, int new_subinteger)
{
  string new_substring = "";
  int start = -1;
    do
    {
        start = text.find(old_substring, start + 1);
        if (start > -1)
        {
          if (new_substring == "")
          {
            char buf_int[9];
            sprintf(buf_int, "%d", new_subinteger);
            new_substring = buf_int;
          }
          text.replace(start, old_substring.length(), new_substring.c_str());
          start += new_substring.length() - old_substring.length();
        }
    }
    while (start > -1);
}
 
// replace char 'find' in string (char* str) by another char 'replace'; return number of replacement
int replace_char(char*& str, char find, char replace)
{
    int replace_count = 0;
    char* cur_pos = strchr(str, find);
    while (cur_pos)
    {
        *cur_pos = replace;
        replace_count++;
        cur_pos = strchr(cur_pos, find);
    }
 
    return replace_count;
}
 
// return string without leading and trailing spaces and tabs
string trim(const string& str, const string& whitespace)
{
    size_t strBegin = str.find_first_not_of(whitespace);
    if (strBegin == string::npos)
        return ""; // no content
 
    size_t strEnd = str.find_last_not_of(whitespace);
    size_t strRange = strEnd - strBegin + 1;
 
    return str.substr(strBegin, strRange);
}
 
// return string changing whitespace and tabs by single whitespace
string reduce(const string& str, const string& fill, const string& whitespace)
{
    // trim first
    string result = trim(str, whitespace);
 
    // replace sub ranges
    size_t beginSpace = result.find_first_of(whitespace);
    while (beginSpace != string::npos)
    {
        size_t endSpace = result.find_first_not_of(whitespace, beginSpace);
        size_t range = endSpace - beginSpace;
 
        result.replace(beginSpace, range, fill);
 
        size_t newStart = beginSpace + fill.length();
        beginSpace = result.find_first_of(whitespace, newStart);
    }
 
    return result;
}
 
// is string ('full_str') ending with the given susbtring ('ending')
bool endswith(string const &full_str, string const &ending)
{
    if (full_str.length() >= ending.length())
        return (0 == full_str.compare(full_str.length() - ending.length(), ending.length(), ending));
    else
        return false;
}
 
 
/*                          */
/*                          */
/*   DIR & FILE FUNCTIONS   */
/*                          */
/*                          */
 
// check directory exists: 0 - not exists, 1 - exists, -2 - cannot access
int check_directory_exist(const char* path)
{
    struct stat info;
 
    if (stat(path, &info) != 0)
        return -2;
    else if (info.st_mode & S_IFDIR)
        return 1;
    else
        return 0;
}
 
// check and create directory if not exists: 0 - not existed before, 1 - existed, -1 - errno error
int create_directory(const char* path)
{
    struct stat info = {0};
 
    if (stat(path, &info) == -1)
    {
        int status = mkdir(path, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
        return status;
    }
    else
    {
        if (info.st_mode & S_IFDIR)
            return 1;
 
        return -2;
    }
}
 
// check and create all non-existent directories in the path:
// 0 - not existed before, 1 - existed, -1 - errno error, -2 - cannot access
int create_directory_tree(const char* path)
{
  string str_path(path);
  size_t pos = str_path.find_last_of('/');
  if (pos == string::npos)
    return 1;
  str_path = str_path.substr(0, pos);
  int status = check_directory_exist(str_path.c_str());
  if (status != 0)
    return status;
 
  status = create_directory_tree(str_path.c_str());
  if (status < 0)
    return status;
 
  mode_t mode = 0755;
  status = mkdir(str_path.c_str(), mode);
  if (status == 0)
    return 0;
    switch (errno)
    {
      case ENOENT:
        return -1;
      case EEXIST:
        return -2;
      default:
        return -1;
    }
}
 
// get file name without extension from a path
string get_file_name(string path)
{
    // Remove directory if present.
    size_t last_slash_idx = path.find_last_of("\\/");
    if (last_slash_idx != string::npos)
        path.erase(0, last_slash_idx + 1);
 
    // Remove extension if present.
    size_t period_idx = path.rfind('.');
    if (period_idx != string::npos)
        path.erase(period_idx);
 
    return path;
}
 
// get file name with extension from path
string get_file_name_with_ext(string path)
{
    // Remove directory if present.
    size_t last_slash_idx = path.find_last_of("\\/");
    if (last_slash_idx != string::npos)
        path.erase(0, last_slash_idx + 1);
 
    return path;
}
 
// get directory path without last slash from file path
string get_directory_path(string file_path)
{
    string directory = "";
    const size_t last_slash_idx = file_path.find_last_of("\\/");
    if (last_slash_idx != string::npos)
        directory = file_path.substr(0, last_slash_idx);
 
    return directory;
}
 
// get directory name from file path
string get_directory_name(string file_path)
{
  string directory = "";
  const size_t last_slash_idx = file_path.find_last_of("\\/");
  if (last_slash_idx != string::npos)
  {
    const size_t penult_slash_idx = file_path.find_last_of("\\/", last_slash_idx-1);
    if (penult_slash_idx != string::npos)
      directory = file_path.substr(penult_slash_idx+1, last_slash_idx-penult_slash_idx-1);
  }
 
  return directory;
}
 
 
/*                  */
/*                  */
/*  TIME FUNCTIONS  */
/*                  */
/*                  */
 
// get current date as string
string get_current_date()
{
    time_t rawtime;
    time(&rawtime);
 
    struct tm* timeinfo;
    timeinfo = localtime(&rawtime);
 
    char buffer[80];
    strftime(buffer, 80, "%d-%m-%Y", timeinfo);
    string str(buffer);
 
    return str;
}
 
// convert string in a given format to datetime struct tm
tm convert_string_to_datetime(string str_datetime, const char* format)
{
    tm tmbuf[1] = {{0}};
    strptime(str_datetime.c_str(), format, tmbuf);
 
    return tmbuf[0];  // tmbuf->tm_year, tmbuf->tm_mon+1, tmbuf->tm_mday, tmbuf->tm_hour, tmbuf->tm_min, tmbuf->tm_sec
}
 
struct timespec convert_double_to_timespec(double sec)
{
  sec += 0.5e-9;
  struct timespec ts = {
    .tv_sec  = (time_t) sec,
    .tv_nsec = (long) (sec - (long)(sec)) * 1000000000,
  };
 
  return ts;
}
 
#endif /* ONLY_DECLARATIONS */
#endif /* FUNCTION_SET_H */