Small compatibility fixes

[dwmw2]

• Echo input from non-tty stdin
• Fix Ctrl-R key handling
• Simple build fixes

[msteveb]

Thanks. C++ support seems fine.

What is the rationale for echoing input. If I do this I get double output. One from the terminal and one from the echo.

$ TERM=dumb ./jimsh
Welcome to Jim version 0.80
. puts hello
puts hello
hello

Regarding reverse-i-search, really - is that how it is supposed to work? How to go forward again after skipping past the one you want? I suppose we have to be compatible, but I prefer mine :-(

[dwmw2]

What is the rationale for echoing input. If I do this I get double output. One from the terminal and one from the echo.

Ah, as noted in the commit comment, this was intended for the case where it isn't a tty. I hadn't spotted that enableRawMode() is also returning failure (and even setting errno = ENOTTY) for the case of unsupported $TERM too.

I'm a little confused by the errno setting... can I make enableRawMode() set errno = ENOTTY only when it literally isn't a tty, and set a different errno in other cases.... or in fact, is anyone even looking? Why set errno at all?

Or just do this perhaps...

--- a/linenoise.c
+++ b/linenoise.c
@@ -1851,7 +1851,7 @@ char *linenoise(const char *prompt)
         printf("%s", prompt);
         fflush(stdout);
         sb = sb_getline(stdin);
-        if (sb) {
+        if (!isatty(current.fd) && sb) {
             printf("%s\n", sb_str(sb));
             fflush(stdout);
         }

[dwmw2]

Regarding reverse-i-search, really - is that how it is supposed to work? How to go forward again after skipping past the one you want? I suppose we have to be compatible, but I prefer mine :-(

Honestly, this is one of those cases where my fingers' muscle memory knows more than my conscious brain. They definitely want that repeated Ctrl-R to keep going backwards.

It turns out that Ctrl-S is the 'search forwards' command, which doesn't actually work in practice unless you do stty -ixon otherwise it gets consumed. But I'll go and implement that; thanks for the reminder.

[msteveb]

Or just do this perhaps...

--- a/linenoise.c
+++ b/linenoise.c
@@ -1851,7 +1851,7 @@ char *linenoise(const char *prompt)
         printf("%s", prompt);
         fflush(stdout);
         sb = sb_getline(stdin);
-        if (sb) {
+        if (!isatty(current.fd) && sb) {
             printf("%s\n", sb_str(sb));
             fflush(stdout);
         }

Yes. That will probably do. Use of errno is probably lost in the mists of time (not literally - it would have come from original linenoise).

[msteveb]

With the ^S change, I think this all looks good but will take some time before I can test thoroughly and merge (busy time leading up to Christmas) so I'll get to it in due course. Thanks.

[dwmw2]

Branch updated and rebased, updated the list of keybindings that you've added in the meantime. Also added @metinkaya's allocation checks from dwmw2#1

[msteveb]

Thanks. I will get to this soon but I won’t be merging the allocation checks. IMHO checking for allocation failure achieves no useful purpose on modern operating systems.

[msteveb]

I merged the earlier commits and made a few small changes to ctrl-r/s
Take a look at https://github.com/msteveb/linenoise/tree/readline-compat-ctrl-r and if ok I will merge it

[msteveb]

I didn't get a response, so I merged that branch. Any problems can be raised in a new issue.