newlib-cygwin/winsup/doc/new-features.sgml

<sect1 id="ov-new1.7"><title>What's new and what changed in Cygwin 1.7</title>

<sect2 id="ov-new1.7-os"><title>OS related changes</title>

<screen>
- Windows 95, 98 and Me are not supported anymore.  The new Cygwin 1.7 DLL
  will not run on any of these systems.

- Add support for Windows 7 and Windows Server 2008 R2.
</screen>

</sect2>

<sect2 id="ov-new1.7-file"><title>File Access related changes</title>

<screen>
- Mount points are no longer stored in the registry.  Use /etc/fstab
  and /etc/fstab.d/$USER instead.  Mount points created with mount(1)
  are only local to the current session and disappear when the last
  Cygwin process in the session exits.

- Cygwin creates the mount points for /, /usr/bin, and /usr/lib automatically
  from it's own position on the disk.  They don't have to be specified in
  /etc/fstab.

- If a filename cannot be represented in the current character set,
  the character will be converted to a sequence Ctrl-X + UTF-8 representation
  of the character.  This allows to access all files, even those not
  having a valid representation of their filename in the current character
  set (codepage).  To always have a valid string, use the UTF-8 charset
  by setting the environment variable $LANG, $LC_ALL, or $LC_CTYPE to a
  valid POSIX value, for instance in Cygwin.bat like this:

    set LC_CTYPE=en_US.UTF-8

- PATH_MAX is now 4096.  Internally, path names can be as long as the
  underlying OS can handle (32K).

- struct dirent now supports d_type, filled out with DT_REG or DT_DIR.
  All other file types return as DT_UNKNOWN for performance reasons.

- The CYGWIN environment variable options "ntsec" and "smbntsec" have
  been replaced by the per-mount option "acl"/"noacl".

- The CYGWIN environment variable option "ntea" has been removed without
  substitute.

- The CYGWIN environment variable option "check_case" has been removed
  in favor of real case-sensitivity on file systems supporting it.

- Creating filenames with special DOS characters '"', '*', ':', '&lt;',
  '&gt;', '|' is supported.

- Creating files with special DOS device filename components ("aux",
  "nul", "prn") is supported.

- File names are case sensitive if the OS and the underlying file system
  supports it.  Works on NTFS and NFS.  Does not work on FAT and Samba
  shares.  Requires to change a registry key (see the user's guide).
  Can be switched off on a per-mount base.

- Due to the above changes, managed mounts have been removed.

- Incoming DOS paths are always handled case-insensitive and get no POSIX
  permission, as if they are mounted with noacl,posix=0 mount flags.

- unlink(2) and rmdir(2) try very hard to remove files/directories even
  if they are currently accessed or locked.  This is done by utilizing
  the hidden recycle bin directories and marking the files for deletion.

- rename(2) rewritten to be more POSIX conformant.

- access(2) now performs checks using the real user ID, as required by
  POSIX; the old behavior of querying based on effective user ID is
  available through the new faccessat(2) and euidaccess(2) APIs.

- Add st_birthtim member to struct stat.

- File locking is now advisory, not mandatory anymore.  The fcntl(2) and
  the new lockf(2) APIs create and maintain locks with POSIX semantics,
  the flock(2) API creates and maintains locks with BSD semantics.
  POSIX and BSD locks are independent of each other.

- Implement atomic O_APPEND mode.

- New open(2) flags O_DIRECTORY, O_EXEC and O_SEARCH.

- Make the "plain file with SYSTEM attribute set" style symlink
  default again when creating symlinks.  Only create Windows shortcut
  style symlinks if CYGWIN=winsymlinks is set in the environment.

- Symlinks now use UTF-16 encoding for the target filename for
  better internationalization support.  Cygwin 1.7 can read all old style
  symlinks, but the new style is not compatible with older Cygwin releases.

- Handle NTFS native symlinks available since Vista/2008 as symlinks
  (but don't create Vista/2008 symlinks due to unfortunate OS restrictions).

- Recognize NFS shares and handle them using native mechanisms.
  Recognize and create real symlinks on NFS shares.  Get correct
  stat(2) information and set real mode bits on open(2), mkdir(2)
  and chmod(2).

- Recognize Netapp DataOnTap drives and fix inode number handling.

- Recognize Samba version beginning with Samba 3.0.28a using the new
  extended version information negotiated with the Samba developers.

- Stop faking hardlinks by copying the file on filesystems which don't
  support hardlinks natively (FAT, FAT32, etc.).  Just return an error
  instead, just like Linux.

- List servers of all accessible domains and workgroups in // instead of
  just the servers in the own domain/workgroup.

- Support Linux-like extended attributes ([fl]getxattr, [fl]listxattr,
  [fl]setxattr, [fl]removexattr).

- New file conversion API for conversion from Win32 to POSIX path and
  vice versa (cygwin_conv_path, cygwin_create_path, cygwin_conv_path_list).

- New openat family of functions: openat, faccessat, fchmodat, fchownat,
  fstatat, futimesat, linkat, mkdirat, mkfifoat, mknodat, readlinkat, renameat,
  symlinkat, unlinkat.

- Other new APIs: posix_fadvise, posix_fallocate, funopen, fopencookie,
  open_memstream, open_wmemstream, fmemopen, fdopendir, fpurge,
  mkstemps, eaccess, euidaccess, canonicalize_file_name, fexecve, execvpe.
</screen>

</sect2>

<sect2 id="ov-new1.7-net"><title>Network related changes</title>

<screen>
- New implementation for blocking sockets and select on sockets which
  is supposed to allow POSIX-compatible sharing of sockets between
  threads and processes.

- send/sendto/sendmsg now send data in 64K chunks to circumvent an
  internal buffer problem in WinSock (KB 201213).

- New send/recv option MSG_DONTWAIT.

- IPv6 support.  New API getaddrinfo, getnameinfo, freeaddrinfo,
  gai_strerror, in6addr_any, in6addr_loopback.  On IPv6-less systems,
  replacement functions are available for IPv4.  On systems with IPv6
  enabled, the underlying WinSock functions are used.  While I tried
  hard to get the functionality as POSIXy as possible, keep in mind that
  a *fully* conformant implementation of getaddrinfo and other stuff is
  only available starting with Windows Vista/2008.

- Resolver functions (res_init, res_query, res_search, res_querydomain,
  res_mkquery, res_send, dn_comp, dn_expand) are now part of Cygwin.
  Applications don't have to link against minires anymore.  Actually,
  this *is* the former libminires.a.

- rcmd is now implemented inside of Cygwin, instead of calling the
  WinSock function.  This allows rsh(1) usage on Vista/2008 and later,
  which dropped this function from WinSock.

- Define multicast structures in netinet/in.h.  Note that fully
  conformant multicast support is only available beginning with Vista/2008.

- Improve get_ifconf.  Redefine struct ifreq and subsequent datastructures
  to be able to keep more information.  Support SIOCGIFINDEX, SIOCGIFDSTADDR
  and the Cygwin specific SIOCGIFFRNDLYNAM.  Support real interface flags
  on systems supporting them.

- Other new APIs: bindresvport, bindresvport_sa, gethostbyname2, iruserok_sa,
  rcmd_af, rresvport_af.  getifaddrs, freeifaddrs, if_nametoindex,
  if_indextoname, if_nameindex, if_freenameindex.

- Add /proc/net/if_inet6.
</screen>

</sect2>

<sect2 id="ov-new1.7-device"><title>Device related changes</title>

<screen>
- Reworked pipe implementation which uses overlapped IO to create
  more reliable interruptible pipes and fifos.

- The CYGWIN environment variable option "binmode" has been removed.

- Improved fifo handling by using native Windows named pipes.

- Detect when a stdin/stdout which looks like a pipe is really a tty.
  Among other things, this allows a debugged application to recognize that
  it is using the same tty as the debugger.

- Support UTF-8 in console window.

- In the console window the backspace key now emits DEL (0x7f) instead
  of BS (0x08), Alt-Backspace emits ESC-DEL (0x1b,0x7f) instead of DEL
  (0x7f), same as the Linux console and xterm.
  Control-Space now emits an ASCII NUL (0x0) character.

- Support up to 64 serial interfaces using /dev/ttyS0 - /dev/ttyS63.

- Support up to 128 raw disk drives /dev/sda - /dev/sddx.

- New API: cfmakeraw, get_avphys_pages, get_nprocs, get_nprocs_conf,
  get_phys_pages, posix_openpt.
</screen>

</sect2>

<sect2 id="ov-new1.7-posix"><title>Other POSIX related changes</title>

<screen>
- A lot of character sets are supported now via a call to setlocale().
  The setting of the environment variables $LANG, $LC_ALL or $LC_CTYPE will
  be used.  For instance, setting $LANG to "de_DE.ISO-8859-15" before
  starting a Cygwin session will use the ISO-8859-15 character set in
  the entire session.  The default charset is "UTF-8", even in the
  default locale "C".  The default locale in the absence of one of the
  aforementioned environment variables is "C.UTF-8".

  The full list of supported character sets: "ASCII", "ISO-8859-x" with x
  in 1-16, except 12, "UTF-8", Windows codepages "CPxxx", with xxx in
  (437, 720, 737, 775, 850, 852, 855, 857, 858, 862, 866, 874, 1125,
  1250, 1251, 1252, 1253, 1254, 1255, 1256, 1257, 1258), "KOI8-R", "KOI8-U",
  "SJIS", "GBK", "eucJP", "eucKR", and "Big5".  The leading language and
  territory part (en_US, for instance) is not used by Cygwin yet, but is
  required for POSIX compatibility.

- Allow multiple concurrent read locks per thread for pthread_rwlock_t.

- Implement pthread_kill(thread, 0) as per POSIX.

- New API for POSIX IPC:
  Named semaphores: sem_open, sem_close, sem_unlink.
  Message queues: mq_open, mq_getattr, mq_setattr, mq_notify, mq_send,
  mq_timedsend, mq_receive, mq_timedreceive, mq_close, mq_unlink.
  Shared memory: shm_open, shm_unlink.

- Only declare expected functions in &lt;strings.h&gt;, don't include
  &lt;string.h&gt; from here.

- Support for WCONTINUED, WIFCONTINUED() added to waitpid and wait4.

- New APIs: _Exit, confstr, insque, remque, sys_sigabbrev,
  posix_madvise, posix_memalign, reallocf,
  exp10, exp10f, pow10, pow10f, lrint, lrintf, rint, rintf, llrint, llrintf,
  llrintl, lrintl, rintl,
  mbsnrtowcs, strcasestr, stpcpy, stpncpy, wcpcpy, wcpncpy, wcsnlen,
  wcsnrtombs, wcsftime, wcstod, wcstof, wcstoimax, wcstok, wcstol, wcstoll,
  wcstoul, wcstoull, wcstoumax, wcsxfrm, wcscasecmp, wcsncasecmp,
  fgetwc, fgetws, fputwc, fputws, fwide, getwc, getwchar, putwc, putwchar,
  ungetwc, asnprintf, dprintf, vasnprintf, vdprintf,
  wprintf, fwprintf, swprintf, vwprintf, vfwprintf, vswprintf,
  wscanf, fwscanf, swscanf, vwscanf, vfwscanf, vswscanf.
</screen>

</sect2>

<sect2 id="ov-new1.7-sec"><title>Security related changes</title>

<screen>
- Getting a domain user's groups is hopefully more bulletproof now.

- Cygwin now comes with a real LSA authentication package.  This must
  be manually installed by a privileged user using the /bin/cyglsa-config
  script.  The advantages and disadvantages are noted in
  http://cygwin.com/ml/cygwin-developers/2006-11/msg00000.html

- Cygwin now allows storage and use of user passwords in a hidden area of
  the registry.  This is tried first when Cygwin is called by privileged
  processes to switch the user context.  This allows, for instance,
  ssh public key sessions with full network credentials to access shares
  on other machines.

- New options have been added to the mkpasswd and mkgroup tools to
  ease use in multi-machine and multi-domain environments.  The existing
  options have a slightly changed behaviour.
</screen>

</sect2>

<sect2 id="ov-new1.7-misc"><title>Miscellaneous</title>

<screen>
- New ldd utility, similar to Linux.

- New link libraries libdl.a, libresolve.a, librt.a.

- Fallout from the long path names: If the current working directory is
  longer than 260 bytes, or if the current working directory is a virtual
  path (like /proc, /cygdrive, //server), don't call native Win32 programs
  since they don't understand these paths.

- On the first usage of a DOS path (C:\foo, \\foo\bar), the Cygwin DLL
  emits a scary warning that DOS paths shouldn't be used.  This warning
  may be disabled via the new CYGWIN=nodosfilewarning setting.

- The CYGWIN environment variable option "server" has been removed.
  Cygwin automatically uses cygserver if it's available.

- Allow environment of arbitrary size instead of a maximum of 32K.

- Don't force uppercase environment when started from a non-Cygwin process.
  Except for certain Windows and POSIX variables which are always uppercased,
  preserve environment case.  Switch back to old behaviour with the new
  CYGWIN=upcaseenv setting.

- Detect and report a missing DLL on process startup.

- Add /proc/registry32 and /proc/registry64 paths to access 32 bit and
  64 bit registry on 64 bit systems.

- Add the ability to distinguish registry keys and registry values with the
  same name in the same registry subtree.  The key is called "foo" and the
  value will be called "foo%val" in this case.

- Align /proc/cpuinfo more closly to Linux content.

- Add /proc/$PID/mounts entries and a symlink /proc/mounts pointing to
  /proc/self/mounts as on Linux.

- Optimized strstr and memmem implementation.

- Remove backwards compatibility with old signal masks.  (Some *very* old
  programs which use signal masks may no longer work correctly).

- Cygwin now exports wrapper functions for libstdc++ operators new and
  delete, to support the toolchain in implementing full C++ standards
  conformance when working with shared libraries.

- Different Cygwin installations in different paths can be run in parallel
  without knowing of each other.  The path of the Cygwin DLL used in a
  process is a key used when creating IPC objects.  So different Cygwin
  DLLs are running in different namespaces.

- Each Cygwin DLL stores its path and installation key in the registry.
  This allows troubleshooting of problems which could be a result of having
  multiple concurrent Cygwin installations.
</screen>

</sect2>

</sect1>