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

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• Hash : 8dffeb6f
  Author :
  Date : 2009-11-14T22:13:10
  

  setenv, unsetenv: work around various bugs
  
  POSIX requires setenv(NULL,"",0), setenv("a=b","",0),
  unsetenv(NULL), and unsetenv("a=b") to fail with EINVAL, but
  many BSD implementations lack validation.  The gnulib
  replacement for void unsetenv did not do validation, and the
  replacement for setenv was out of sync with glibc.  Also, some
  BSD implementations of setenv("a","==",1) eat the leading '='.
  
  See also some recent Austin Group interpretations on environ:
  http://austingroupbugs.net/view.php?id=167
  http://austingroupbugs.net/view.php?id=185
  
  * lib/setenv.c (setenv) [!HAVE_SETENV]: Resync from glibc.
  (setenv) [HAVE_SETENV]: Work around bugs.
  * lib/unsetenv.c (unsetenv) [HAVE_UNSETENV]: Work around bugs.
  * m4/setenv.m4 (gl_FUNC_SETENV_SEPARATE, gl_FUNC_UNSETENV): Check
  for bugs.
  (gl_FUNC_SETENV): Write in terms of gl_FUNC_SETENV_SEPARATE.
  * m4/environ.m4 (gl_ENVIRON): Avoid expand-before-require.
  * m4/stdlib_h.m4 (gl_STDLIB_H_DEFAULTS): Update defaults.
  * modules/stdlib (Makefile.am): Update substitutions.
  * lib/stdlib.in.h (setenv, unsetenv): Update prototypes.
  * doc/posix-functions/setenv.texi (setenv): Document the bugs.
  * doc/posix-functions/unsetenv.texi (unsetenv): Likewise.
  * modules/setenv-tests: New test.
  * modules/unsetenv-tests: Likewise.
  * tests/test-setenv.c: New file.
  * tests/test-unsetenv.c: Likewise.
  
  Signed-off-by: Eric Blake <ebb9@byu.net>
  

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• doc/posix-functions/unsetenv.texi

• @node unsetenv
  @section @code{unsetenv}
  @findex unsetenv
  
  POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/unsetenv.html}
  
  Gnulib module: setenv
  
  Portability problems fixed by Gnulib:
  @itemize
  @item
  This function is missing on some platforms:
  AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 9, mingw, BeOS.
  @item
  This function has the return type @samp{void} instead of @samp{int} on some
  platforms:
  MacOS X 10.3, FreeBSD 6.0, NetBSD 1.6, OpenBSD 3.8, OSF/1 5.1.
  @item
  On some platforms, this function does not fail with @samp{EINVAL} when
  passed a null pointer, an empty string, or a string containing @samp{=}:
  FreeBSD 6.0, NetBSD 1.6, OpenBSD 3.8.
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
  @end itemize
  

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