Windows – write function requires unistd.h on Unix, what about windows

cposixunistd.hvisual studiowindows

I've changed from a linux computer to a windows and I'm having trouble compiling my code because these two OS don't share the same header files.

Since the unistd.h is not obviously included, Visual C doesn't know what read(), write(), close(), socklen_t() and bzero()functions are. Can anyone help me with this?

I've googled this: Is there a replacement for unistd.h for Windows (Visual C)?

I have no idea how unistd.h works, nor do I know how to code my own. Can someone please link me to one?

Best Answer

read, write and close are in <io.h>, just like they traditionally were on Unix.

Offhand, I don't know of a bzero being included on Windows at all -- if you care at all about portability, you normally want to use memset instead.

socklen_t isn't normally used on Windows -- most things that would be socklen_t on Unix use either size_t or int on Windows (socklen_t on Unix is currently another reference to the same underlying type as size_t, added in case it might be useful someday -- aka, a solution in search of a problem).

Related Solutions

C++ – replacement for unistd.h for Windows (Visual C)

Since we can't find a version on the Internet, let's start one here.
Most ports to Windows probably only need a subset of the complete Unix file.
Here's a starting point. Please add definitions as needed.

#ifndef _UNISTD_H
#define _UNISTD_H    1

/* This is intended as a drop-in replacement for unistd.h on Windows.
 * Please add functionality as neeeded.
 * https://stackoverflow.com/a/826027/1202830
 */

#include <stdlib.h>
#include <io.h>
#include <getopt.h> /* getopt at: https://gist.github.com/ashelly/7776712 */
#include <process.h> /* for getpid() and the exec..() family */
#include <direct.h> /* for _getcwd() and _chdir() */

#define srandom srand
#define random rand

/* Values for the second argument to access.
   These may be OR'd together.  */
#define R_OK    4       /* Test for read permission.  */
#define W_OK    2       /* Test for write permission.  */
//#define   X_OK    1       /* execute permission - unsupported in windows*/
#define F_OK    0       /* Test for existence.  */

#define access _access
#define dup2 _dup2
#define execve _execve
#define ftruncate _chsize
#define unlink _unlink
#define fileno _fileno
#define getcwd _getcwd
#define chdir _chdir
#define isatty _isatty
#define lseek _lseek
/* read, write, and close are NOT being #defined here, because while there are file handle specific versions for Windows, they probably don't work for sockets. You need to look at your app and consider whether to call e.g. closesocket(). */

#ifdef _WIN64
#define ssize_t __int64
#else
#define ssize_t long
#endif

#define STDIN_FILENO 0
#define STDOUT_FILENO 1
#define STDERR_FILENO 2
/* should be in some equivalent to <sys/types.h> */
typedef __int8            int8_t;
typedef __int16           int16_t; 
typedef __int32           int32_t;
typedef __int64           int64_t;
typedef unsigned __int8   uint8_t;
typedef unsigned __int16  uint16_t;
typedef unsigned __int32  uint32_t;
typedef unsigned __int64  uint64_t;

#endif /* unistd.h  */

Windows equivalent to UNIX pwd

This prints it in the console:

echo %cd%

or paste this command in CMD, then you'll have pwd:

(echo @echo off
echo echo ^%cd^%) > C:\WINDOWS\pwd.bat

Best Answer

Related Solutions

C++ – replacement for unistd.h for Windows (Visual C)

Windows equivalent to UNIX pwd

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