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Disable interactive mode (-a) if readline not available

php.internals

Nikita Popov

5 years ago
Hi internals, If the readline extension is enabled, PHP provides an interactive shell under -a. If it is not enabled, it falls back to an "interactive mode" (yes, the difference between "interactive shell" and "interactive mode" is important here). The interactive mode is simply an stdin input, which needs to be terminated using Ctrl+D. You can only run one script that way. I think the current behavior is quite confusing, because it's really not obvious that you ended up in this fallback mode (you need to know the difference between "shell" and "mode" in the output) and most people wouldn't know what to do with it. The latest instance of this is https://bugs.php.net/bug.php?id=81033. I think we would be better off disabling -a completely if readline is not available, and exit with a helpful error message. I've opened https://github.com/php/php-src/pull/6976 to that effect. Does that sound reasonable? Regards, Nikita

Moritz Friedrich

5 years ago
> Am 12.05.2021 um 10:12 schrieb Nikita Popov <nikita.ppv@gmail.com>: > > Hi internals, > > If the readline extension is enabled, PHP provides an interactive shell > under -a. If it is not enabled, it falls back to an "interactive mode" > (yes, the difference between "interactive shell" and "interactive mode" is > important here). The interactive mode is simply an stdin input, which needs > to be terminated using Ctrl+D. You can only run one script that way. > > I think the current behavior is quite confusing, because it's really not > obvious that you ended up in this fallback mode (you need to know the > difference between "shell" and "mode" in the output) and most people > wouldn't know what to do with it. The latest instance of this is > https://bugs.php.net/bug.php?id=81033. > > I think we would be better off disabling -a completely if readline is not > available, and exit with a helpful error message. I've opened > https://github.com/php/php-src/pull/6976 to that effect. Does that sound > reasonable? > > Regards, > Nikita
Hi Nikita, if I may ask, would it also be possible to have deadline as a mandatory dependency to always have the interactive shell available? Is there a good reason to compile PHP without? Having a basic prompt available is really handy at times — especially looking at Node.js with their ahead-completion and general UX. The same has been done for other PHP modules in the past, so I wonder if we could simply have readline as a guarantee. Regards, Moritz

Nikita Popov

5 years ago
On Wed, May 12, 2021 at 10:37 AM Moritz Friedrich <m@9dev.de> wrote:
> > > Am 12.05.2021 um 10:12 schrieb Nikita Popov <nikita.ppv@gmail.com>: > > > > Hi internals, > > > > If the readline extension is enabled, PHP provides an interactive shell > > under -a. If it is not enabled, it falls back to an "interactive mode" > > (yes, the difference between "interactive shell" and "interactive mode" > is > > important here). The interactive mode is simply an stdin input, which > needs > > to be terminated using Ctrl+D. You can only run one script that way. > > > > I think the current behavior is quite confusing, because it's really not > > obvious that you ended up in this fallback mode (you need to know the > > difference between "shell" and "mode" in the output) and most people > > wouldn't know what to do with it. The latest instance of this is > > https://bugs.php.net/bug.php?id=81033. > > > > I think we would be better off disabling -a completely if readline is not > > available, and exit with a helpful error message. I've opened > > https://github.com/php/php-src/pull/6976 to that effect. Does that sound > > reasonable? > > > > Regards, > > Nikita > > Hi Nikita, > if I may ask, would it also be possible to have deadline as a mandatory > dependency to always have the interactive shell available? Is there a good > reason to compile PHP without? Having a basic prompt available is really > handy at times — especially looking at Node.js with their ahead-completion > and general UX. > The same has been done for other PHP modules in the past, so I wonder if > we could simply have readline as a guarantee.
The readline extension has an external dependency on readline / libedit. Making it a required extension would also make this a required dependency. We avoid having dependencies for the minimal build. The only dependency we currently have is libpcre, and we vendor that one. I doubt we'll want to add a new vendored dependency, as they tend to be a major pain. I personally do not use the interactive shell (and I think most people who do use *an* interactive shell prefer psysh), so I don't think this can be reasonably considered a "required" feature. Regards, Nikita

Joe Watkins

5 years ago
Morning Nikita, +1 on the change to cli. It can't really be a default extension right now because readline license is not compatible: https://github.com/php/php-src/pull/3823 Even without the license problem, I'm not convinced of the value of adding the dependency: Because of this long standing strange behaviour, I don't really think the interactive shell is well used. Cheers Joe On Wed, 12 May 2021 at 10:48, Nikita Popov <nikita.ppv@gmail.com> wrote:

Pierre

5 years ago
Le 12/05/2021 à 11:29, Joe Watkins a écrit :
> Morning Nikita, > > +1 on the change to cli. > > It can't really be a default extension right now because readline license > is not compatible: > > https://github.com/php/php-src/pull/3823 > > Even without the license problem, I'm not convinced of the value of adding > the dependency: Because of this long standing strange behaviour, I don't > really think the interactive shell is well used.
Hello, I might be an exception, I don't know, but I do use it a lot (almost every day). I don't want to install psysh or anything like it, php -a is enough for what I do with it. Regards, Pierre

Michelangelo van Dam

5 years ago
> On 12 May 2021, at 11:39, Pierre <pierre-php@processus.org> wrote: > > Le 12/05/2021 à 11:29, Joe Watkins a écrit : >> Morning Nikita, >> >> +1 on the change to cli. >> >> It can't really be a default extension right now because readline license >> is not compatible: >> >> https://github.com/php/php-src/pull/3823 >> >> Even without the license problem, I'm not convinced of the value of adding >> the dependency: Because of this long standing strange behaviour, I don't >> really think the interactive shell is well used. > > Hello, > > I might be an exception, I don't know, but I do use it a lot (almost every day). I don't want to install psysh or anything like it, php -a is enough for what I do with it. > > Regards, > > Pierre > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: https://www.php.net/unsub.php >
Hello, I’m using php -a daily on CLI to quickly try out hypothesis or evaluate expressions. No interest in using other tools. Cheers, Michelangelo

Nikita Popov

5 years ago
On Wed, May 12, 2021 at 11:44 AM Michelangelo van Dam <dragonbe@gmail.com> wrote:
> > > > On 12 May 2021, at 11:39, Pierre <pierre-php@processus.org> wrote: > > > > Le 12/05/2021 à 11:29, Joe Watkins a écrit : > >> Morning Nikita, > >> > >> +1 on the change to cli. > >> > >> It can't really be a default extension right now because readline > license > >> is not compatible: > >> > >> https://github.com/php/php-src/pull/3823 > >> > >> Even without the license problem, I'm not convinced of the value of > adding > >> the dependency: Because of this long standing strange behaviour, I don't > >> really think the interactive shell is well used. > > > > Hello, > > > > I might be an exception, I don't know, but I do use it a lot (almost > every day). I don't want to install psysh or anything like it, php -a is > enough for what I do with it. > > > > Regards, > > > > Pierre > > > > -- > > PHP Internals - PHP Runtime Development Mailing List > > To unsubscribe, visit: https://www.php.net/unsub.php > > > > Hello, > > I’m using php -a daily on CLI to quickly try out hypothesis or evaluate > expressions. No interest in using other tools. >
Everyone, let's please keep discussion relating to the interactive shell *with* readline out of this thread. Unless you are using the interactive mode *without* readline, your usage will not be affected by the proposed change. If you want to discuss improvements to php -a *with* readline, then please do so in a different thread. Regards, Nikita

Joe Watkins

5 years ago
Morning, Still I think heavy use has to be the exception, especially heavy use where readline is not available (because it's questionably useful). Cheers Joe On Wed, 12 May 2021 at 11:39, Pierre <pierre-php@processus.org> wrote:

Christoph Becker

5 years ago
On 12.05.2021 at 10:12, Nikita Popov wrote:
> I think we would be better off disabling -a completely if readline is not > available, and exit with a helpful error message. I've opened > https://github.com/php/php-src/pull/6976 to that effect. Does that sound > reasonable?
I'm in favor of dropping the interactive mode. Thank you for the PR! I wonder, though, if there is even a difference between `php -a` (without readline) and `php` (besides the "interactive mode" message).
-- Christoph M. Becker

Nikita Popov

5 years ago
On Wed, May 12, 2021 at 3:42 PM Christoph M. Becker <cmbecker69@gmx.de> wrote:
> On 12.05.2021 at 10:12, Nikita Popov wrote: > > > I think we would be better off disabling -a completely if readline is not > > available, and exit with a helpful error message. I've opened > > https://github.com/php/php-src/pull/6976 to that effect. Does that sound > > reasonable? > > I'm in favor of dropping the interactive mode. Thank you for the PR! > > I wonder, though, if there is even a difference between `php -a` > (without readline) and `php` (besides the "interactive mode" message). >
I don't think there's any difference. Nikita

Bob Weinand

5 years ago
> Am 12.05.2021 um 10:12 schrieb Nikita Popov <nikita.ppv@gmail.com>: > > Hi internals, > > If the readline extension is enabled, PHP provides an interactive shell > under -a. If it is not enabled, it falls back to an "interactive mode" > (yes, the difference between "interactive shell" and "interactive mode" is > important here). The interactive mode is simply an stdin input, which needs > to be terminated using Ctrl+D. You can only run one script that way. > > I think the current behavior is quite confusing, because it's really not > obvious that you ended up in this fallback mode (you need to know the > difference between "shell" and "mode" in the output) and most people > wouldn't know what to do with it. The latest instance of this is > https://bugs.php.net/bug.php?id=81033. > > I think we would be better off disabling -a completely if readline is not > available, and exit with a helpful error message. I've opened > https://github.com/php/php-src/pull/6976 to that effect. Does that sound > reasonable? > > Regards, > Nikita
Hey Nikita, yes, please merge that PR, I've been annoyed more than once that the php -a was not actually interactive despite a seemingly good message. (and as cmb noted, it's effectively identical to bare php without args.) Bob

Aaron Piotrowski

5 years ago
> On May 12, 2021, at 3:12 AM, Nikita Popov <nikita.ppv@gmail.com> wrote: > > Hi internals, > > If the readline extension is enabled, PHP provides an interactive shell > under -a. If it is not enabled, it falls back to an "interactive mode" > (yes, the difference between "interactive shell" and "interactive mode" is > important here). The interactive mode is simply an stdin input, which needs > to be terminated using Ctrl+D. You can only run one script that way. > > I think the current behavior is quite confusing, because it's really not > obvious that you ended up in this fallback mode (you need to know the > difference between "shell" and "mode" in the output) and most people > wouldn't know what to do with it. The latest instance of this is > https://bugs.php.net/bug.php?id=81033. > > I think we would be better off disabling -a completely if readline is not > available, and exit with a helpful error message. I've opened > https://github.com/php/php-src/pull/6976 to that effect. Does that sound > reasonable? > > Regards, > Nikita
This would have been helpful several years ago when I started compiling PHP myself and was confused why `php -a` broke. An error message would have saved me some time. So yes, please, merge it. Aaron Piotrowski

David Gebler

5 years ago
On Wed, 12 May 2021, 09:13 Nikita Popov, <nikita.ppv@gmail.com> wrote:
> > I think we would be better off disabling -a completely if readline is not > available, and exit with a helpful error message. I've opened > https://github.com/php/php-src/pull/6976 to that effect. Does that sound > reasonable? > > Regards, > Nikita >
+1 for this, the shell is very useful but "interactive mode", the evidence is clear has a tendency to confuse people. To invert the question, would anyone have a good justification to NOT remove interactive mode?

Unnamed Person

5 years ago
On Wed, May 12, 2021 at 10:13 AM David Gebler <davidgebler@gmail.com> wrote:
> > On Wed, 12 May 2021, 09:13 Nikita Popov, <nikita.ppv@gmail.com> wrote: > > > > > I think we would be better off disabling -a completely if readline is not > > available, and exit with a helpful error message. I've opened > > https://github.com/php/php-src/pull/6976 to that effect. Does that sound > > reasonable? > > > > Regards, > > Nikita > > > > +1 for this, the shell is very useful but "interactive mode", the evidence > is clear has a tendency to confuse people. > To invert the question, would anyone have a good justification to NOT > remove interactive mode?
I've never once ran `php -a` and wanted the behavior that comes if you don't have readline or libedit available. As has been mentioned, if you want that behavior run `php` without -a. There's no loss of functionality here, methinks. As long as `php -a` gives a sensible message if it wasn't built with readline or libedit that says such: The interactive shell requires libedit or readline support, which this build does not have. Run php without -a to get an interactive mode instead. Or something.

Rowan Collins

5 years ago
On 12/05/2021 17:21, Levi Morrison via internals wrote:
> The interactive shell requires libedit or readline support, which > this build does not have. > Run php without -a to get an interactive mode instead.
Unless I'm missing something, the default CLI mode (php without -a) is "interactive PHP" only if you consider "cat > foo.txt" to be an "interactive editor". You can type a complete script (remembering to start with "<?php"), hit Ctrl-D (if you happen to know that that means "end of file") and it will execute it, then exit. I too have been stung by accidentally triggering this mode without readline enabled, and would be happy to see Nikita's patch merged. Regards,
-- Rowan Tommins [IMSoP]

Niklas Keller

5 years ago
Hey all, please remember that you can also use php -r to quickly evaluate expressions, e.g. generating a random password: php -r 'var_dump(bin2hex(random_bytes(16)));' I'm in favor of removal without readline. Best, Niklas Rowan Tommins <rowan.collins@gmail.com> schrieb am Mi., 12. Mai 2021, 22:46: