Re: [PATCH] Environment variable convenience function

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 23 Apr 2023 10:07:55 -0700
> From: Keith Seitz via Gdb-patches <gdb-patches@sourceware.org>
> 
> This patch adds a new Python convenience function which simply
> returns the value of the given environment variable (or a default value)
> or throws a KeyError.
> 
> (gdb) p $_env("HOME")
> $1 = "/home/keiths"
> (gdb) p $_env("IS_THIS_USEFUL")
> Python Exception <class 'KeyError'>: 'IS_THIS_USEFUL'
> Error occurred in Python: 'IS_THIS_USEFUL'
> (gdb) p $_env("IS_THIS_USEFUL", "yes")
> $2 = "yes"
> ---
>  gdb/NEWS                            |  3 +++
>  gdb/data-directory/Makefile.in      |  1 +
>  gdb/doc/gdb.texinfo                 |  7 ++++++
>  gdb/python/lib/gdb/function/env.py  | 38 +++++++++++++++++++++++++++++
>  gdb/testsuite/gdb.base/default.exp  |  1 +
>  gdb/testsuite/gdb.python/py-env.c   | 22 +++++++++++++++++
>  gdb/testsuite/gdb.python/py-env.exp | 38 +++++++++++++++++++++++++++++
>  7 files changed, 110 insertions(+)
>  create mode 100644 gdb/python/lib/gdb/function/env.py
>  create mode 100644 gdb/testsuite/gdb.python/py-env.c
>  create mode 100644 gdb/testsuite/gdb.python/py-env.exp

Thanks.

> diff --git a/gdb/NEWS b/gdb/NEWS
> index 54b5da21245..4897b1e618b 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -156,6 +156,9 @@ info main
>       (program-counter) values, and can be used as the frame-id when
>       calling gdb.PendingFrame.create_unwind_info.
>  
> +  ** New Python-based convenience function $_env(name[, default]), which
> +     returns the string value of the environment variable of the given name.

This part is OK.

> +@findex $_env@r{, convenience function}
> +@item $_env(@var{name}@r{[}, @var{default}@r{]})
> +Return the value of the environment variable named @var{name}.
> +
> +If the variable is not defined in the environment, the optional default value
> +is returned, if specified, or a Python exception is thrown.

The last sentence abuses the passive voice, so I suggest to rephrase:

  If the variable @var{name} is not defined in the environment, the
  function returns the vale of the optional argument @var{default},
  and if that was not specified, it throws a Python exception.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>