Re: getchar implementation without GNUishms

In article <vrvv30$spj$1@nnrp.usenet.blueworldhosting.com>,
Arti F. Idiot <addr@is.invalid> wrote:

On 3/25/25 7:10 AM, Janis Papanagnou wrote:

On 25.03.2025 10:51, anthk wrote:

Hello the guy from https://luxferre.top and gopher://hoi.st
has pretty interesting stuff, such as
>
[ shell specific or other tries to emulate some getchar function ]
>
Could it be possible to implement a true portable getchar?

 
Those who think that getchar is a useful function may implement that
natively in Awk. (It avoids external dependencies and all the issues
that the posted/quoted code has made obvious.)

>
>
I know you can iterate over input strings a character at a time in AWK
but I don't think you can read a single character from stdin without
also providing a newline via ENTER, which is perhaps what the OP was
actually wanting to do?

This works for me:

--- Cut Here ---
@load "call_any"
BEGIN {
    system("stty raw -echo");
    s = " "
    n = call_any("iisi","read",0,s,1)
    system("stty sane");
    print "s =","|"s"|","n =",n
    }
--- Cut Here ---

Note: I could probably change the system() calls to use call_any() as well.

It looks like tcgetattr(3) and tcsetattr(3) are the currently accepted ways
of doing this.  I've used those calls in my C programs, so would have to
adapt that to work with call_any().

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