[bug-gawk] Gawk Handles Late-In-Command-Line -v Variable Assignments Differently When -e and -f Are Omitted

[Neil R. Ormos]

Hello Arnold et al.:

In the examples below, only in Example 6, where
source code is provided on the command line
without -e, and where a variable assignment is
provided after the source code, is the result of
the variable assignment not available in the BEGIN
rule.

I don't know if this is intended behavior or a
bug.  I was unable to find an explanation in the
manual.  (If I missed something, please forgive.)

The results below use Gawk 5.0.0 compiled from the
tar achive from ftp.gnu.org, but I get the same
results using 4.2.0 and 3.1.7 (substituting
--source= for -e).

Best regards,

--Neil Ormos

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> uname -a
Linux aloha 4.9.0-8-amd64 #1 SMP Debian 4.9.130-2 (2018-10-27) x86_64 GNU/Linux

> lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 9.7 (stretch)
Release:        9.7
Codename:       stretch

> gawk --version | head -1
GNU Awk 5.0.0, API: 2.0

> echo 'BEGIN{print a}' > ! test.awk

> cat -n test.awk
     1  BEGIN{print a}


# Example 1
>            gawk -v a=99 -f test.awk
99

# Example 2
>            gawk         -f test.awk         -v a=99
99

# Example 3
>            gawk -v a=99 -e 'BEGIN{print a}'
99

# Example 4
>            gawk         -e 'BEGIN{print a}' -v a=99
99

# Example 5
>            gawk -v a=99    'BEGIN{print a}'
99

# Example 6
>            gawk            'BEGIN{print a}' -v a=99

# The line above was empty.

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