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PATH is an environment variable on Unix-like operating systems, DOS, OS/2, and Microsoft Windows, specifying a set of directories where executable programs are located. In general, each executing process or user session has its own PATH setting.
type Command The type command can not only show the path of a Linux command, but it can also tell if the target is built-in, a function, an alias, or an external executable.
If you want to know the current location, in which folder or directory you are while using Windows CMD (Command Line Interface), you can make use of cd command, Command: cd - This command can be used to displays the name of or to change the current directory.
There is no cross platform way that I know.
For Linux: readlink /proc/self/exe
Windows: GetModuleFileName
The boost::dll::program_location function is one of the best cross platform methods of getting the path of the running executable that I know of. The DLL library was added to Boost in version 1.61.0.
The following is my solution. I have tested it on Windows, Mac OS X, Solaris, Free BSD, and GNU/Linux.
It requires Boost 1.55.0 or greater. It uses the Boost.Filesystem library directly and the Boost.Locale library and Boost.System library indirectly.
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <iterator>
#include <string>
#include <vector>
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/predef.h>
#include <boost/version.hpp>
#include <boost/tokenizer.hpp>
#if (BOOST_VERSION > BOOST_VERSION_NUMBER(1,64,0))
# include <boost/process.hpp>
#endif
#if (BOOST_OS_CYGWIN || BOOST_OS_WINDOWS)
# include <Windows.h>
#endif
#include <boost/executable_path.hpp>
#include <boost/detail/executable_path_internals.hpp>
namespace boost {
#if (BOOST_OS_CYGWIN || BOOST_OS_WINDOWS)
std::string executable_path(const char* argv0)
{
typedef std::vector<char> char_vector;
typedef std::vector<char>::size_type size_type;
char_vector buf(1024, 0);
size_type size = buf.size();
bool havePath = false;
bool shouldContinue = true;
do
{
DWORD result = GetModuleFileNameA(nullptr, &buf[0], size);
DWORD lastError = GetLastError();
if (result == 0)
{
shouldContinue = false;
}
else if (result < size)
{
havePath = true;
shouldContinue = false;
}
else if (
result == size
&& (lastError == ERROR_INSUFFICIENT_BUFFER || lastError == ERROR_SUCCESS)
)
{
size *= 2;
buf.resize(size);
}
else
{
shouldContinue = false;
}
} while (shouldContinue);
if (!havePath)
{
return detail::executable_path_fallback(argv0);
}
// On Microsoft Windows, there is no need to call boost::filesystem::canonical or
// boost::filesystem::path::make_preferred. The path returned by GetModuleFileNameA
// is the one we want.
std::string ret = &buf[0];
return ret;
}
#elif (BOOST_OS_MACOS)
# include <mach-o/dyld.h>
std::string executable_path(const char* argv0)
{
typedef std::vector<char> char_vector;
char_vector buf(1024, 0);
uint32_t size = static_cast<uint32_t>(buf.size());
bool havePath = false;
bool shouldContinue = true;
do
{
int result = _NSGetExecutablePath(&buf[0], &size);
if (result == -1)
{
buf.resize(size + 1);
std::fill(std::begin(buf), std::end(buf), 0);
}
else
{
shouldContinue = false;
if (buf.at(0) != 0)
{
havePath = true;
}
}
} while (shouldContinue);
if (!havePath)
{
return detail::executable_path_fallback(argv0);
}
std::string path(&buf[0], size);
boost::system::error_code ec;
boost::filesystem::path p(
boost::filesystem::canonical(path, boost::filesystem::current_path(), ec));
if (ec.value() == boost::system::errc::success)
{
return p.make_preferred().string();
}
return detail::executable_path_fallback(argv0);
}
#elif (BOOST_OS_SOLARIS)
# include <stdlib.h>
std::string executable_path(const char* argv0)
{
std::string ret = getexecname();
if (ret.empty())
{
return detail::executable_path_fallback(argv0);
}
boost::filesystem::path p(ret);
if (!p.has_root_directory())
{
boost::system::error_code ec;
p = boost::filesystem::canonical(
p, boost::filesystem::current_path(), ec);
if (ec.value() != boost::system::errc::success)
{
return detail::executable_path_fallback(argv0);
}
ret = p.make_preferred().string();
}
return ret;
}
#elif (BOOST_OS_BSD)
# include <sys/sysctl.h>
std::string executable_path(const char* argv0)
{
typedef std::vector<char> char_vector;
int mib[4]{0};
size_t size;
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_PATHNAME;
mib[3] = -1;
int result = sysctl(mib, 4, nullptr, &size, nullptr, 0);
if (-1 == result)
{
return detail::executable_path_fallback(argv0);
}
char_vector buf(size + 1, 0);
result = sysctl(mib, 4, &buf[0], &size, nullptr, 0);
if (-1 == result)
{
return detail::executable_path_fallback(argv0);
}
std::string path(&buf[0], size);
boost::system::error_code ec;
boost::filesystem::path p(
boost::filesystem::canonical(
path, boost::filesystem::current_path(), ec));
if (ec.value() == boost::system::errc::success)
{
return p.make_preferred().string();
}
return detail::executable_path_fallback(argv0);
}
#elif (BOOST_OS_LINUX)
# include <unistd.h>
std::string executable_path(const char *argv0)
{
typedef std::vector<char> char_vector;
typedef std::vector<char>::size_type size_type;
char_vector buf(1024, 0);
size_type size = buf.size();
bool havePath = false;
bool shouldContinue = true;
do
{
ssize_t result = readlink("/proc/self/exe", &buf[0], size);
if (result < 0)
{
shouldContinue = false;
}
else if (static_cast<size_type>(result) < size)
{
havePath = true;
shouldContinue = false;
size = result;
}
else
{
size *= 2;
buf.resize(size);
std::fill(std::begin(buf), std::end(buf), 0);
}
} while (shouldContinue);
if (!havePath)
{
return detail::executable_path_fallback(argv0);
}
std::string path(&buf[0], size);
boost::system::error_code ec;
boost::filesystem::path p(
boost::filesystem::canonical(
path, boost::filesystem::current_path(), ec));
if (ec.value() == boost::system::errc::success)
{
return p.make_preferred().string();
}
return detail::executable_path_fallback(argv0);
}
#else
std::string executable_path(const char *argv0)
{
return detail::executable_path_fallback(argv0);
}
#endif
}
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <iterator>
#include <string>
#include <vector>
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/predef.h>
#include <boost/version.hpp>
#include <boost/tokenizer.hpp>
#if (BOOST_VERSION > BOOST_VERSION_NUMBER(1,64,0))
# include <boost/process.hpp>
#endif
#if (BOOST_OS_CYGWIN || BOOST_OS_WINDOWS)
# include <Windows.h>
#endif
#include <boost/executable_path.hpp>
#include <boost/detail/executable_path_internals.hpp>
namespace boost {
namespace detail {
std::string GetEnv(const std::string& varName)
{
if (varName.empty()) return "";
#if (BOOST_OS_BSD || BOOST_OS_CYGWIN || BOOST_OS_LINUX || BOOST_OS_MACOS || BOOST_OS_SOLARIS)
char* value = std::getenv(varName.c_str());
if (!value) return "";
return value;
#elif (BOOST_OS_WINDOWS)
typedef std::vector<char> char_vector;
typedef std::vector<char>::size_type size_type;
char_vector value(8192, 0);
size_type size = value.size();
bool haveValue = false;
bool shouldContinue = true;
do
{
DWORD result = GetEnvironmentVariableA(varName.c_str(), &value[0], size);
if (result == 0)
{
shouldContinue = false;
}
else if (result < size)
{
haveValue = true;
shouldContinue = false;
}
else
{
size *= 2;
value.resize(size);
}
} while (shouldContinue);
std::string ret;
if (haveValue)
{
ret = &value[0];
}
return ret;
#else
return "";
#endif
}
bool GetDirectoryListFromDelimitedString(
const std::string& str,
std::vector<std::string>& dirs)
{
typedef boost::char_separator<char> char_separator_type;
typedef boost::tokenizer<
boost::char_separator<char>, std::string::const_iterator,
std::string> tokenizer_type;
dirs.clear();
if (str.empty())
{
return false;
}
#if (BOOST_OS_WINDOWS)
const std::string os_pathsep(";");
#else
const std::string os_pathsep(":");
#endif
char_separator_type pathSep(os_pathsep.c_str());
tokenizer_type strTok(str, pathSep);
typename tokenizer_type::iterator strIt;
typename tokenizer_type::iterator strEndIt = strTok.end();
for (strIt = strTok.begin(); strIt != strEndIt; ++strIt)
{
dirs.push_back(*strIt);
}
if (dirs.empty())
{
return false;
}
return true;
}
std::string search_path(const std::string& file)
{
if (file.empty()) return "";
std::string ret;
#if (BOOST_VERSION > BOOST_VERSION_NUMBER(1,64,0))
{
namespace bp = boost::process;
boost::filesystem::path p = bp::search_path(file);
ret = p.make_preferred().string();
}
#endif
if (!ret.empty()) return ret;
// Drat! I have to do it the hard way.
std::string pathEnvVar = GetEnv("PATH");
if (pathEnvVar.empty()) return "";
std::vector<std::string> pathDirs;
bool getDirList = GetDirectoryListFromDelimitedString(pathEnvVar, pathDirs);
if (!getDirList) return "";
std::vector<std::string>::const_iterator it = pathDirs.cbegin();
std::vector<std::string>::const_iterator itEnd = pathDirs.cend();
for ( ; it != itEnd; ++it)
{
boost::filesystem::path p(*it);
p /= file;
if (boost::filesystem::exists(p) && boost::filesystem::is_regular_file(p))
{
return p.make_preferred().string();
}
}
return "";
}
std::string executable_path_fallback(const char *argv0)
{
if (argv0 == nullptr) return "";
if (argv0[0] == 0) return "";
#if (BOOST_OS_WINDOWS)
const std::string os_sep("\\");
#else
const std::string os_sep("/");
#endif
if (strstr(argv0, os_sep.c_str()) != nullptr)
{
boost::system::error_code ec;
boost::filesystem::path p(
boost::filesystem::canonical(
argv0, boost::filesystem::current_path(), ec));
if (ec.value() == boost::system::errc::success)
{
return p.make_preferred().string();
}
}
std::string ret = search_path(argv0);
if (!ret.empty())
{
return ret;
}
boost::system::error_code ec;
boost::filesystem::path p(
boost::filesystem::canonical(
argv0, boost::filesystem::current_path(), ec));
if (ec.value() == boost::system::errc::success)
{
ret = p.make_preferred().string();
}
return ret;
}
}
}
#ifndef BOOST_EXECUTABLE_PATH_HPP_
#define BOOST_EXECUTABLE_PATH_HPP_
#pragma once
#include <string>
namespace boost {
std::string executable_path(const char * argv0);
}
#endif // BOOST_EXECUTABLE_PATH_HPP_
#ifndef BOOST_DETAIL_EXECUTABLE_PATH_INTERNALS_HPP_
#define BOOST_DETAIL_EXECUTABLE_PATH_INTERNALS_HPP_
#pragma once
#include <string>
#include <vector>
namespace boost {
namespace detail {
std::string GetEnv(const std::string& varName);
bool GetDirectoryListFromDelimitedString(
const std::string& str,
std::vector<std::string>& dirs);
std::string search_path(const std::string& file);
std::string executable_path_fallback(const char * argv0);
}
}
#endif // BOOST_DETAIL_EXECUTABLE_PATH_INTERNALS_HPP_
I have a complete project, including a test application and CMake build files available at SnKOpen - /cpp/executable_path/trunk. This version is more complete than the version I provided here. It is also supports more platforms.
I have tested the application on all supported operating systems in the following four scenarios.
In all four scenarios, both the executable_path and executable_path_fallback functions work and return the same results.
This is an updated answer to this question. I updated the answer to take into consideration user comments and suggestions. I also added a link to a project in my SVN Repository.
This way uses boost + argv. You mentioned this may not be cross platform because it may or may not include the executable name. Well the following code should work around that.
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <iostream>
namespace fs = boost::filesystem;
int main(int argc,char** argv)
{
fs::path full_path( fs::initial_path<fs::path>() );
full_path = fs::system_complete( fs::path( argv[0] ) );
std::cout << full_path << std::endl;
//Without file name
std::cout << full_path.stem() << std::endl;
//std::cout << fs::basename(full_path) << std::endl;
return 0;
}
The following code gets the current working directory which may do what you need
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <iostream>
namespace fs = boost::filesystem;
int main(int argc,char** argv)
{
//current working directory
fs::path full_path( fs::current_path<fs::path>() );
std::cout << full_path << std::endl;
std::cout << full_path.stem() << std::endl;
//std::cout << fs::basepath(full_path) << std::endl;
return 0;
}
Note
Just realized that basename() was deprecated so had to switch to .stem()
I'm not sure about Linux, but try this for Windows:
#include <windows.h>
#include <iostream>
using namespace std ;
int main()
{
char ownPth[MAX_PATH];
// When NULL is passed to GetModuleHandle, the handle of the exe itself is returned
HMODULE hModule = GetModuleHandle(NULL);
if (hModule != NULL)
{
// Use GetModuleFileName() with module handle to get the path
GetModuleFileName(hModule, ownPth, (sizeof(ownPth)));
cout << ownPth << endl ;
system("PAUSE");
return 0;
}
else
{
cout << "Module handle is NULL" << endl ;
system("PAUSE");
return 0;
}
}
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