Re: The 'source x' command doesn't keep variables set by x when source output is piped into other command

[Oğuz]

On Saturday, November 16, 2024, Martin D Kealey <martin@kurahaupo.gen.nz>
wrote:

> (Insert this between the "Copyright" and "Description" sections)
>
>
> *“PrefaceDear reader, if this is your introduction to the Shell programming
> language, please be aware that although it may look like other languages
> you are familiar with, such similarity is deceptive. The shell language is
> different in subtle and non-obvious ways from all (*1) other languages, and
> making assumptions based on what you know from other languages will lead
> you into traps. Please read the "Shell Grammar" section, allowing **time to
> digest it **slowly and thoroughly, and then read at least one of the
> recommended tutorials listed in appendix B. If you are unsure whether you
> fully understand the Shell, please take the test in appendix A.”*
>
>
> (Insert this after the "Bugs" section)
>
>
>
>
>
> *“Appendix A: a self-test to check understanding of basic principles.If you
> have trouble answering these questions then you should read one of the
> tutorials in Appendix B before consulting this manual. It will also be
> helpful to read the "Shell Grammar" section. Please write down your answer
> to each question, and then run its code (*2) to see if its behaviour
> matches your answer. There is no pass or fail mark, but any mismatch
> indicates that you would likely benefit from revision.*
> *1. What will be displayed when you run this: foo=bar ; echo zot | read foo
> ; echo "$foo"*
>
> *2. What will be displayed when you run this: export foo=bar ; foo=zot ;
> env | grep ^foo=*
> *3.  ...” *(additional questions welcome)
>
>
> *“Appendix B: Recommended TutorialsBefore consulting this manual, we
> recommend reading: https://mywiki.wooledge.org/BashGuide
> <https://mywiki.wooledge.org/BashGuide> *http://guide.bash.academy/*
> etc...
> We recommend avoiding the so-called Advanced Bash-Scripting Guide on *
> tldp.org <https://tldp.org/LDP/abs/html/>
> *...”*(additional reading suggestions welcome)
>
> -Martin
>
> (*1: yes I know it's an offshoot of the UNIX v7 shell, and other similar
> languages were designed around the same time, but they're all dead now, and
> certainly won't be encountered by a neophyte reading this manual page in
> 2024.)
>
> (*2: this may require some finessing of nroff to ensure that it does NOT
> substitute curly quotes or otherwise mess with the shell syntax, so that
> users can simply copy & paste the example code to test it)
>

This belongs in separate, unofficial document; not the reference manual,
which is fine as is.


-- 
Oğuz