Converting launch_activate_socket() from C to Pascal - issues
lazarus / 38-Networking and Web Programming

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trev · 2021-05-04 10:44

After having successfully converted  the SampleD C daemon code into
working, non-deprecated C code (ie replacing the deprecated ASL
logging with OSLog; replacing the myriad deprecated launch_ functions
with launch_activate_socket) my quest to convert it into Pascal has
hit a pot hole, er, wall.

My working, converted, C code:

Code: C  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i #include
<launch.h>[...] int *listening_fd_array; size_t
listening_fds_count; int err;[...]err =
launch_activate_socket("MySocket", &listening_fd_array,
&listening_fds_count);if (err != 0) {   os_log_error(OS_LOG_DEFAULT,
"launch_activate_socket() failed error %d (%s)", err,
strerror(err));} if (NULL == listening_fd_array) {   
os_log_error(OS_LOG_DEFAULT, "No known sockets found to answer
requests on!");    retval = EXIT_FAILURE;    goto done;}
My failed Pascal attempt:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
launch_activate_socket(const name: string; var fds: PInteger; cnt:
size_t): integer; external name '_launch_activate_socket'; [...]var 
err : integer;  listening_fd_array: PInteger;  listening_fds_count:
size_t; [...]err := launch_activate_socket('MySocket',
listening_fd_array, listening_fds_count);if(err <> 0) then  begin   
if(err = ENOENT) then      writeln('Error: Socket not found in plist
file (', err, ')')    else if(err = ESRCH) then      writeln('Error:
Calling process is not managed by launchd (', err, ')')    else if(err
= EALREADY) then      writeln('Error: Socket already activated (',
err, ')')    else      writeln('Error: ', err);  end; if(Nil =
listening_fds_count) then  begin    writeln('No known sockets found to
answer requests on!');    goto Done;  end;
Where did I go wrong? It compiles successfully, but errors out with
ESRCH and "No known sockets...".

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PascalDragon · 2021-05-04 11:10

I have really strong doubts that launch_activate_socket as a C
function takes a Pascal string instead of a PChar. Also shouldn't your
cnt parameter be a var (or out) as well?
(Also I doubt that Nil = listening_fds_count does indeed compile)

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trev · 2021-05-04 12:45

Dang (cut 'n paste errors from another version):
- Nil should have been 0
- string should have been pchar

Thanks - I'd missed the missing var. No more spurious errors

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PascalDragon · 2021-05-05 07:07

Quote from: trev on May 04, 2021, 02:45:51 pmThanks - I'd missed the
missing var. No more spurious errors

You're welcome.