kc3-lang/gnulib/doc/posix-functions/dup2.texi

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• Hash : cfcb5fc6
  Author :
  Date : 2020-07-08T02:52:09
  

  dup2: Remove support for some very old platforms.
  
  * m4/dup2-obsolete.m4: Remove file.
  * modules/dup2-obsolete: Remove file.
  * m4/dup2.m4 (gl_FUNC_DUP2): Assume module 'dup2-obsolete' is absent.
  Don't define HAVE_DUP2.
  * lib/unistd.in.h (dup2): Assume HAVE_DUP2 is 1.
  * lib/dup2.c: Likewise.
  * modules/dup2 (Depends-on, configure.ac): Likewise.
  (Depends-on): Remove dup2-obsolete.
  * m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Don't initialize HAVE_DUP2.
  * modules/unistd (Makefile.am): Don't substitute HAVE_DUP2.
  * doc/posix-functions/dup2.texi: Don't mention module 'dup2-obsolete'.
  

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• doc/posix-functions/dup2.texi

• @node dup2
  @section @code{dup2}
  @findex dup2
  
  POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/dup2.html}
  
  Gnulib module: dup2
  
  Portability problems fixed by Gnulib:
  @itemize
  @item
  This function is declared in a different header file (namely, @code{<io.h>})
  on some platforms:
  MSVC 14.
  
  @item
  This function always returns 0 for success on some platforms:
  mingw, MSVC 14.
  
  @item
  This function can hang when duplicating an fd to itself on some platforms:
  mingw, MSVC 14.
  
  @item
  This function crashes when invoked with invalid arguments on some platforms:
  Cygwin 1.7.17, MSVC 14.
  
  @item
  This function crashes when invoked with valid arguments on some platforms:
  Cygwin 1.7.25.
  
  @item
  This function fails with @code{EINVAL} when duplicating an fd to itself:
  Android.
  
  @item
  This function resets the @code{FD_CLOEXEC} flag when duplicating an fd
  to itself on some platforms:
  Haiku.
  
  @item
  This function returns 0 for @code{dup2 (1, 1)} on some platforms:
  Cygwin 1.5.x.
  
  @item
  This function may return @code{-EBADF} instead of @code{-1} on some platforms:
  Linux releases between July 2008 and May 2009 (versions 2.6.27 to 2.6.29).
  
  @item
  This function returns @code{EMFILE} instead of @code{EBADF} for
  large targets, which interferes with using
  @code{dup2(fd,fd)==fd)} as the minimal @code{EBADF} filter:
  AIX 7.1, FreeBSD 6.1, Cygwin 1.5.
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
  @end itemize
  

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