根据QNX Neutrino版本的不同，有不同的方法来查找用于启动运行进程的可执行文件的完整路径和名称。我将进程标识符表示为<PID>。试试下面的方法:

If the file /proc/self/exefile exists, then its contents are the requested information. If the file /proc/<PID>/exefile exists, then its contents are the requested information. If the file /proc/self/as exists, then: open() the file. Allocate a buffer of, at least, sizeof(procfs_debuginfo) + _POSIX_PATH_MAX. Give that buffer as input to devctl(fd, DCMD_PROC_MAPDEBUG_BASE,.... Cast the buffer to a procfs_debuginfo*. The requested information is at the path field of the procfs_debuginfo structure. Warning: For some reason, sometimes, QNX omits the first slash / of the file path. Prepend that / when needed. Clean up (close the file, free the buffer, etc.). Try the procedure in 3. with the file /proc/<PID>/as. Try dladdr(dlsym(RTLD_DEFAULT, "main"), &dlinfo) where dlinfo is a Dl_info structure whose dli_fname might contain the requested information.

我希望这能有所帮助。

当然，这并不适用于所有项目。 尽管如此，QCoreApplication::applicationFilePath()在6年的c++ /Qt开发中从未让我失望过。

当然，在尝试使用它之前，应该彻底阅读文档:

警告:在Linux上，此函数将尝试从 /proc文件系统。如果失败，则假定argv[0]包含 可执行文件的绝对文件名。这个函数也假设 应用程序没有更改当前目录。

老实说，我认为#ifdef和其他类似的解决方案根本不应该在现代代码中使用。

我相信更小的跨平台库也存在。让他们把所有特定于平台的东西封装在里面。

这只是我的个人意见。通过使用这段代码，您可以在具有跨平台接口的C/ c++中找到当前应用程序的目录。

void getExecutablePath(char ** path, unsigned int * pathLength)
{
    // Early exit when invalid out-parameters are passed
    if (!checkStringOutParameter(path, pathLength))
    {
        return;
    }

#if defined SYSTEM_LINUX

    // Preallocate PATH_MAX (e.g., 4096) characters and hope the executable path isn't longer (including null byte)
    char exePath[PATH_MAX];

    // Return written bytes, indicating if memory was sufficient
    int len = readlink("/proc/self/exe", exePath, PATH_MAX);

    if (len <= 0 || len == PATH_MAX) // memory not sufficient or general error occured
    {
        invalidateStringOutParameter(path, pathLength);
        return;
    }

    // Copy contents to caller, create caller ownership
    copyToStringOutParameter(exePath, len, path, pathLength);

#elif defined SYSTEM_WINDOWS

    // Preallocate MAX_PATH (e.g., 4095) characters and hope the executable path isn't longer (including null byte)
    char exePath[MAX_PATH];

    // Return written bytes, indicating if memory was sufficient
    unsigned int len = GetModuleFileNameA(GetModuleHandleA(0x0), exePath, MAX_PATH);
    if (len == 0) // memory not sufficient or general error occured
    {
        invalidateStringOutParameter(path, pathLength);
        return;
    }

    // Copy contents to caller, create caller ownership
    copyToStringOutParameter(exePath, len, path, pathLength);

#elif defined SYSTEM_SOLARIS

    // Preallocate PATH_MAX (e.g., 4096) characters and hope the executable path isn't longer (including null byte)
    char exePath[PATH_MAX];

    // Convert executable path to canonical path, return null pointer on error
    if (realpath(getexecname(), exePath) == 0x0)
    {
        invalidateStringOutParameter(path, pathLength);
        return;
    }

    // Copy contents to caller, create caller ownership
    unsigned int len = strlen(exePath);
    copyToStringOutParameter(exePath, len, path, pathLength);

#elif defined SYSTEM_DARWIN

    // Preallocate PATH_MAX (e.g., 4096) characters and hope the executable path isn't longer (including null byte)
    char exePath[PATH_MAX];

    unsigned int len = (unsigned int)PATH_MAX;

    // Obtain executable path to canonical path, return zero on success
    if (_NSGetExecutablePath(exePath, &len) == 0)
    {
        // Convert executable path to canonical path, return null pointer on error
        char * realPath = realpath(exePath, 0x0);

        if (realPath == 0x0)
        {
            invalidateStringOutParameter(path, pathLength);
            return;
        }

        // Copy contents to caller, create caller ownership
        unsigned int len = strlen(realPath);
        copyToStringOutParameter(realPath, len, path, pathLength);

        free(realPath);
    }
    else // len is initialized with the required number of bytes (including zero byte)
    {
        char * intermediatePath = (char *)malloc(sizeof(char) * len);

        // Convert executable path to canonical path, return null pointer on error
        if (_NSGetExecutablePath(intermediatePath, &len) != 0)
        {
            free(intermediatePath);
            invalidateStringOutParameter(path, pathLength);
            return;
        }

        char * realPath = realpath(intermediatePath, 0x0);

        free(intermediatePath);

        // Check if conversion to canonical path succeeded
        if (realPath == 0x0)
        {
            invalidateStringOutParameter(path, pathLength);
            return;
        }

        // Copy contents to caller, create caller ownership
        unsigned int len = strlen(realPath);
        copyToStringOutParameter(realPath, len, path, pathLength);

        free(realPath);
    }

#elif defined SYSTEM_FREEBSD

    // Preallocate characters and hope the executable path isn't longer (including null byte)
    char exePath[2048];

    unsigned int len = 2048;

    int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };

    // Obtain executable path by syscall
    if (sysctl(mib, 4, exePath, &len, 0x0, 0) != 0)
    {
        invalidateStringOutParameter(path, pathLength);
        return;
    }

    // Copy contents to caller, create caller ownership
    copyToStringOutParameter(exePath, len, path, pathLength);

#else

    // If no OS could be detected ... degrade gracefully
    invalidateStringOutParameter(path, pathLength);

#endif
}

你可以在这里详细看看。

根据QNX Neutrino版本的不同，有不同的方法来查找用于启动运行进程的可执行文件的完整路径和名称。我将进程标识符表示为<PID>。试试下面的方法:

If the file /proc/self/exefile exists, then its contents are the requested information. If the file /proc/<PID>/exefile exists, then its contents are the requested information. If the file /proc/self/as exists, then: open() the file. Allocate a buffer of, at least, sizeof(procfs_debuginfo) + _POSIX_PATH_MAX. Give that buffer as input to devctl(fd, DCMD_PROC_MAPDEBUG_BASE,.... Cast the buffer to a procfs_debuginfo*. The requested information is at the path field of the procfs_debuginfo structure. Warning: For some reason, sometimes, QNX omits the first slash / of the file path. Prepend that / when needed. Clean up (close the file, free the buffer, etc.). Try the procedure in 3. with the file /proc/<PID>/as. Try dladdr(dlsym(RTLD_DEFAULT, "main"), &dlinfo) where dlinfo is a Dl_info structure whose dli_fname might contain the requested information.

我希望这能有所帮助。

但是我想知道是否有一种方便的方法来找到当前应用程序的目录在C/ c++与跨平台接口。

你不能这样做(至少在Linux上)

因为一个可执行文件可以，在运行它的进程执行期间，重命名(2)它的文件路径到不同的目录(同一文件系统)。请参见syscalls(2)和inode(7)。

在Linux上，一个可执行文件(原则上)甚至可以通过调用unlink(2)来删除(3)本身。Linux内核应该继续分配该文件，直到没有进程再引用它为止。使用proc(5)，你可以做一些奇怪的事情(例如重命名(2)/proc/self/exe文件，等等…)

换句话说，在Linux上，“当前应用程序的目录”的概念没有任何意义。

请参阅高级Linux编程和操作系统:三个简单的部分。

还可以在OSDEV上查看一些开源操作系统(包括FreeBSD或GNU Hurd)。其中一些提供了接近POSIX的接口(API)。

考虑使用(在获得许可的情况下)跨平台c++框架，如Qt或POCO，也许可以通过将它们移植到您喜欢的操作系统来对它们做出贡献。

除了mark4o的答案，FreeBSD也有

const char* getprogname(void)

它应该也可以在macOS中使用。它可以通过libbsd在GNU/Linux中获得。