Re: [Bug-apl] strange behavior of --

[Xiao-Yong Jin]

I would guess he is using zsh instead of bash.
zsh allows interpreter after #! without an absolute path, irrelevant of the OS 
kernel.

Try running the following script under zsh:

---- SCRIPT BEGIN ----
#!bash
echo 'this will fail'
---- SCRIPT END ----

You will get

---- OUTPUT BEGIN ----
bash: echo 'this will fail'
: No such file or directory
---- OUTPUT END ----

Zsh under both Linux and OSX should give this error, because zsh is making the 
syscall with its own interpretation of the shebang line.

On the other hand, with the absolute path, you get the standard OSX kernel 
handling the syscall.
Google gives a detailed list of behaviors on a webpage
http://www.in-ulm.de/~mascheck/various/shebang/
Your code supporting argv[1] with a concatenated string like '-l 37 --script 
--' may not be the best practice, IMHO, and should be avoided.

Putting more than 1 argument on the shebang line is calling for troubles if you 
want cross OS/kernel support.

> On Feb 6, 2017, at 12:43 PM, Juergen Sauermann <address@hidden> wrote:
> 
> Hi Alexey,
> 
> very odd indeed. It very much looks like OSX is starting apl but then not 
> piping
> the subsequent lines of the script into APL. As if they are opening the 
> script with
> popen() instead of execve(). Its probably more a problem of the shell than of
> the entire OS.
> 
> I would also believe that after starting the script you are in immediate 
> execution
> mode in GNU APL but with input echo off (apl was started with --script).
> 
> I suppose if you replace '--' by '-f' in your first script line (without 
> mentioning the
> script name as I proposed earlier), then it should work.
> 
> BTW a non-absolute path does not work in GNU/APL, which shows how different 
> the
> platforms are in this area.
> 
> /// Jürgen
> 
> 
> On 02/06/2017 06:45 PM, Alexey Veretennikov wrote:
>> Hi!
>> 
>> Finally I've down to something.
>> So the difference is whether I specify full path to apl in a file
>> header.
>> Consider:
>> head -1 aaa.apl
>> #!apl -l 37 --script --
>> 
>> sizeof(Svar_record) is    328
>> sizeof(Svar_partner) is   28
>> increasing rlimit RLIMIT_NPROC from 709 to infinity
>> 
>> initializing paths from argv[0] = apl
>> initializing paths from  $PATH = 
>> /Users/alexeyv/Applications:/Users/alexeyv/Development/stm32tools:/Users/alexeyv/Development/arm-eabi-toolchain/arm-cs-tools-2012.03-56-e3f4013-20130413/bin:/Users/alexeyv/Development/gapl:/Users/alexeyv/.cabal/bin:/Users/alexeyv/Development/gradle-2.3/bin:/Users/alexeyv/Development/groovy-2.4.3/bin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/Library/TeX/texbin
>> APL_bin_path is: /Users/alexeyv/Development/gapl
>> APL_bin_name is: apl
>> Reading config file 
>> /Users/alexeyv/Development/gapl/etc/gnu-apl.d/preferences ...
>> Reading config file /Users/alexeyv/.gnu-apl/preferences ...
>> Reading config file 
>> /Users/alexeyv/Development/gapl/etc/gnu-apl.d/parallel_thresholds ...
>> Not reading config file /Users/alexeyv/.config/gnu-apl/parallel_thresholds 
>> (not found/readable)
>> 0 input files:
>> using ANSI terminal output ESC sequences (or those configured in your 
>> preferences file(s))
>> using ANSI terminal input ESC sequences(or those configured in your 
>> preferences file(s))
>> Using TCP socket towards APserver...
>> connecting to 127.0.0.1 TCP port 16366 failed.
>>     (the first ::connect() to APserver is expected to fail, unless
>>      APserver was started manually)
>> Starting a new APserver listening on 127.0.0.1 TCP port 16366
>> Found /Users/alexeyv/Development/gapl/APserver
>> Starting /Users/alexeyv/Development/gapl/APserver --port 16366 --auto...
>> 
>> connecting to 127.0.0.1 TCP port 16366 failed.
>>     (::connect() should succeed eventually. This was attempt 1 of 5)
>> connecting to 127.0.0.1 TCP port 16366 failed.
>>     (::connect() should succeed eventually. This was attempt 2 of 5)
>> connecting to 127.0.0.1 TCP port 16366 failed.
>>     (::connect() should succeed eventually. This was attempt 3 of 5)
>> connecting to 127.0.0.1 TCP port 16366 failed.
>> ::connect() to supposedly existing APserver failed: Invalid argument
>> PID is 14426
>> argc: 3
>>   argv[0]: 'apl'
>>   argv[1]: '-l 37 --script --'
>>   argv[2]: './aaa.apl'
>> stdin is: OPEN
>> uprefs.user_do_svars:   1
>> uprefs.system_do_svars: 1
>> uprefs.requested_id:    0
>> uprefs.requested_par:   0
>> Svar_DB not connected in Svar_DB::is_registered_id()
>> id.proc: 1001 at ProcessorID.cc:77
>> Processor ID was completely initialized: 1001:0:0
>> system_do_svars is: 1
>> ┌→──────────────────────────────────────────┐
>> │┌→──┐ ┌→─┐ ┌→─┐ ┌→───────┐ ┌→─┐ ┌→────────┐│
>> ││apl│ │-l│ │37│ │--script│ │--│ │./aaa.apl││
>> │└───┘ └──┘ └──┘ └────────┘ └──┘ └─────────┘│
>> └∊──────────────────────────────────────────┘
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> However:
>> 
>> 
>> head -1 bbb.apl
>> #!/Users/alexeyv/Development/gapl/apl -l 37 --script --
>> 
>> 
>> 
>> ./bbb.apl
>> sizeof(Svar_record) is    328
>> sizeof(Svar_partner) is   28
>> increasing rlimit RLIMIT_NPROC from 709 to infinity
>> 
>> initializing paths from argv[0] = /Users/alexeyv/Development/gapl/apl
>> initializing paths from  $PWD = /Users/alexeyv/Sources/apl
>> APL_bin_path is: /Users/alexeyv/Development/gapl
>> APL_bin_name is: apl
>> Reading config file 
>> /Users/alexeyv/Development/gapl/etc/gnu-apl.d/preferences ...
>> Reading config file /Users/alexeyv/.gnu-apl/preferences ...
>> Reading config file 
>> /Users/alexeyv/Development/gapl/etc/gnu-apl.d/parallel_thresholds ...
>> Not reading config file /Users/alexeyv/.config/gnu-apl/parallel_thresholds 
>> (not found/readable)
>> 0 input files:
>> using ANSI terminal output ESC sequences (or those configured in your 
>> preferences file(s))
>> using ANSI terminal input ESC sequences(or those configured in your 
>> preferences file(s))
>> Using TCP socket towards APserver...
>> connected to APserver, socket is 4
>> using Svar_DB on APserver!
>> PID is 14455
>> argc: 6
>>   argv[0]: '/Users/alexeyv/Development/gapl/apl'
>>   argv[1]: '-l'
>>   argv[2]: '37'
>>   argv[3]: '--script'
>>   argv[4]: '--'
>>   argv[5]: './bbb.apl'
>> stdin is: OPEN
>> uprefs.user_do_svars:   1
>> uprefs.system_do_svars: 1
>> uprefs.requested_id:    0
>> uprefs.requested_par:   0
>> id.proc: 1001 at ProcessorID.cc:77
>> Processor ID was completely initialized: 1001:0:0
>> system_do_svars is: 1
>> 
>> 
>> 
>> 
>> 
>> - Here it hangs.
>> Here you see what depending on whether we have a full path in the first
>> line command line arguments interpreted differently. Very odd.
>> 
>> 
>> 
>> 
>> Juergen Sauermann 
>> <address@hidden>
>>  writes:
>> 
>> 
>>> Hi Alexey,
>>> 
>>> but then everything is just fine, isn't it? I believe in an 
>>> earlier post you said that in OSX you don't see any output and have to type 
>>> )OFF
>>> blindly (which suggest that you didn't have a working stdin)?
>>> 
>>> /// Jürgen
>>> 
>>> On 02/06/2017 05:53 PM, Alexey Veretennikov wrote:
>>> 
>>>  Hi,
>>> 
>>> Here are the results:
>>> 
>>> sizeof(Svar_record) is    328
>>> sizeof(Svar_partner) is   28
>>> increasing rlimit RLIMIT_NPROC from 709 to infinity
>>> 
>>> initializing paths from argv[0] = apl
>>> initializing paths from  $PATH = 
>>> /Users/alexeyv/Applications:/Users/alexeyv/Development/stm32tools:/Users/alexeyv/Development/arm-eabi-toolchain/arm-cs-tools-2012.03-56-e3f4013-20130413/bin:/Users/alexeyv/Development/gapl:/Users/alexeyv/.cabal/bin:/Users/alexeyv/Development/gradle-2.3/bin:/Users/alexeyv/Development/groovy-2.4.3/bin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/Library/TeX/texbin
>>> APL_bin_path is: /Users/alexeyv/Development/gapl
>>> APL_bin_name is: apl
>>> Reading config file 
>>> /Users/alexeyv/Development/gapl/etc/gnu-apl.d/preferences ...
>>> Reading config file /Users/alexeyv/.gnu-apl/preferences ...
>>> Reading config file 
>>> /Users/alexeyv/Development/gapl/etc/gnu-apl.d/parallel_thresholds ...
>>> Not reading config file /Users/alexeyv/.config/gnu-apl/parallel_thresholds 
>>> (not found/readable)
>>> 0 input files:
>>> using ANSI terminal output ESC sequences (or those configured in your 
>>> preferences file(s))
>>> using ANSI terminal input ESC sequences(or those configured in your 
>>> preferences file(s))
>>> Using TCP socket towards APserver...
>>> connected to APserver, socket is 4
>>> using Svar_DB on APserver!
>>> PID is 13743
>>> argc: 3
>>>   argv[0]: 'apl'
>>>   argv[1]: '-l 37 --script --'
>>>   argv[2]: './aaa.apl'
>>> stdin is: OPEN
>>> uprefs.user_do_svars:   1
>>> uprefs.system_do_svars: 1
>>> uprefs.requested_id:    0
>>> uprefs.requested_par:   0
>>> id.proc: 1001 at ProcessorID.cc:77
>>> Processor ID was completely initialized: 1001:0:0
>>> system_do_svars is: 1
>>> ┌→──────────────────────────────────────────┐
>>> │┌→──┐ ┌→─┐ ┌→─┐ ┌→───────┐ ┌→─┐ ┌→────────┐│
>>> ││apl│ │-l│ │37│ │--script│ │--│ │./aaa.apl││
>>> │└───┘ └──┘ └──┘ └────────┘ └──┘ └─────────┘│
>>> └∊──────────────────────────────────────────┘
>>> 
>>> 
>>> Juergen Sauermann 
>>> <address@hidden>
>>>  writes:
>>> 
>>>  Hi,
>>> 
>>> i have added a check if stdin is open when GNU APL starts, SVN 881.
>>> 
>>> If you start the following script:
>>> 
>>> #!/usr/local/bin/apl -l 37 --script --
>>> 
>>> ]BOXING ¯8
>>> ⎕ARG
>>> )off
>>> 
>>> Then we can see if stdin is open on OSX and how apl is being called in OSX.
>>> 
>>> /// Jürgen
>>> 
>>> On 02/06/2017 11:21 AM, Juergen Sauermann wrote:
>>> 
>>>  Hi Alexey,
>>> 
>>>  yes. I changed it recently to fix the '--' issue.
>>> 
>>>  A GNU APL script assumes that it was called by execve(). The expand_argv() 
>>> function
>>>  "undoes" the behavior of execve(), which lumps together all arguments on 
>>> the first script line
>>>  into argv[1] of GNU APL's main(argc, argv) functions. In that process the 
>>> filename of the script
>>>  gets lost (or may not even exist, e.g. in a pipe) so -f could be used to 
>>> tell the script where to
>>>  fetch its input. This is because execve() had already closed the file 
>>> descriptor before it called
>>>  apl, so apl has no stdin when it starts. With -f you point apl to re-open 
>>> the input file again.
>>> 
>>>  /// Jürgen
>>> 
>>>  On 02/05/2017 09:24 PM, Alexey Veretennikov wrote:
>>> 
>>>  Ok, as I understand I need to take a look at
>>> UserPreferences::expand_argv
>>> and
>>> UserPreferences::is_APL_script
>>> 
>>> correct?
>>> 
>>> Juergen Sauermann 
>>> <address@hidden>
>>>  writes:
>>> 
>>>  Hi,
>>> 
>>> yes, most of this trouble is caused by how execve() works, which is quite 
>>> different
>>> on different platforms. And it happens before apl is being called so I cant 
>>> do much
>>> about it.
>>> 
>>> Sometimes it helps to start apl with -f so that the interpreter knows where 
>>> to fetch
>>> its input, like:
>>> 
>>> #!/usr/local/bin/apl -f /home/eedjsa/tmp/script --script --
>>> 
>>> /// Jürgen
>>> 
>>> On 02/04/2017 02:00 PM, Alexey Veretennikov wrote:
>>> 
>>>  Hi Juergen,
>>> 
>>> Something is apparently strange on OSX(?). With the latest version
>>> when I run the same script below I get the silent input without
>>> echoing, no output like below, and I have to blindly type )off manually
>>> to exit interpreter.
>>> 
>>> 
>>> Juergen Sauermann 
>>> <address@hidden>
>>>  writes:
>>> 
>>>  Hi Alexey,
>>> 
>>> I have changed the handling of command line options, SVN 877.
>>> 
>>> It now works like this:
>>> 
>>> script:
>>> 
>>> #!/usr/local/bin/apl --script --
>>> 
>>> )copy 5 FILE_IO FIO∆errno
>>> 8⎕CR ⎕ARG
>>> )off
>>> 
>>> output:
>>> 
>>> address@hidden:~/tmp$ ./script scriptarg
>>> DUMPED 2017-01-28 22:57:44 (GMT+1)
>>> ┌→──────────────────────────────────────────────────────────┐
>>> 
>>> │┌→─────────────────┐ ┌→───────┐ ┌→─┐ ┌→───────┐
>>> ┌→────────┐│
>>> ││/usr/local/bin/apl│ │--script│ │--│ │./script│ │scriptarg││
>>> │└──────────────────┘ └────────┘ └──┘ └────────┘
>>> └─────────┘│
>>> └∊──────────────────────────────────────────────────────────┘
>>> 
>>> 
>>> /// Jürgen
>>> 
>>> On 02/03/2017 11:06 PM, Alexey Veretennikov wrote:
>>> 
>>>  Hi,
>>> 
>>> Yes ./script -- myarg works.
>>> 
>>> The problem is why I have to repeat -- in command line since I've
>>> already specified it in the first line of the script, as it is specified
>>> in documentiation.
>>> 
>>> Basically I would like to pass my arguments to the script without
>>> mentioning "--" in the command line.
>>> 
>>> Juergen Sauermann 
>>> <address@hidden>
>>>  writes:
>>> 
>>>  Hi Alexey,
>>> 
>>> how about this:
>>> 
>>> address@hidden:~/tmp$ ./script -- arg**
>>> **DUMPED 2017-01-28 22:57:44 (GMT+1)**
>>> **┌→────────────────────────────────────────────────────┐**
>>> **│┌→─────────────────┐ ┌→───────┐ ┌→───────┐ ┌→─┐ ┌→──┐│**
>>> **││/usr/local/bin/apl│ │--script│ │./script│ │--│ │arg││**
>>> **│└──────────────────┘ └────────┘ └────────┘ └──┘ └───┘│**
>>> **└∊────────────────────────────────────────────────────┘*
>>> 
>>> There is no point (and it does not work) to put the arguments in the first 
>>> line
>>> of the script,
>>> because if the script itself knows them then the rest of the script can use 
>>> them
>>> as well.
>>> 
>>> *⎕ARG *is what is passed to the script, not what is passed to the 
>>> interpreter
>>> mentioned in the script.
>>> See also *man execve*.
>>> 
>>> /// Jürgen
>>> 
>>> 
>>> On 02/03/2017 08:29 PM, Alexey Veretennikov wrote:
>>> 
>>>  Given the following script:
>>> ------------------------------------------
>>> #!apl --script --
>>> )copy 5 FILE_IO FIO∆errno
>>> 8⎕CR ⎕ARG
>>> )off
>>> ------------------------------------------
>>> when I try to run it like
>>> 
>>> ./script.apl myarg
>>> 
>>> I get the error:
>>> 
>>> /script.apl myarg
>>> unknown option 'myarg'
>>> ...
>>> 
>>> This happens on 833 and 1.5 and on both linux and osx.
>>> 
>>> In INFO file it explicitely states:
>>> 
>>> "Using ’—-’ as last argument on the first line of the script file
>>> prevents any of the options given to the script to be interpreted as APL
>>> options; all such options are passed to the application via ⎕ARG."
>>> 
>>> But it is not happening.
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>