valdi@rhi.hi.is (Thorvaldur Sigurdsson) (03/20/90)
Subject: Unix (HP-UX) system call from ADA Newsgroups: comp.sys.hp,comp.lang.ada Keywords: ADA Problem : Making unix system calls within Ada code Background : HP-UX 6.5, HP 9000/300 series, Alsys 4.35 Ada compiler Error message : ld: Undefined external - _ll _clear ld: output file still contains undefined symbols ld: (Warning) did not generate an output file ada: Errors detected Manual : Reference Manual for the Ada Programming Language, Appendix F, page F-5, chapter F 1.1.4 Additional Information on INTERFACE and INTERFACE_NAME : "When you want to call an HP-UX system call from Ada code, you should use a pragma INTERFACE with C as the language name. It is not necassary to provide the C object file to the binder, because it will be found automatically when the linker searches the system library". Question : Is the manual wrong concerning automatic linking or am I doing something wrong in the code ? Source code : main.ada, system.ads main.ada : The following source is the main procedure -- ************************************************ -- * ABSTRACT: Main program * -- ************************************************ procedure MAIN is begin UNIX_SYSTEM_CALL.clear; UNIX_SYSTEM_CALL.ll; end MAIN; system.ads : The following source is the unix_system_call package -- ************************************************ -- * ABSTRACT: Package specification * -- ************************************************ package UNIX_SYSTEM_CALL is procedure clear; procedure ll; private pragma INTERFACE (C, clear); -- clear display pragma INTERFACE (C, ll); -- long list end UNIX_SYSTEM_CALL; -- package specification P.S. : I tried also implementing the usage of INTERFACE_NAME without results. ------------------------------------------------------------------------ Thorvaldur Egill Sigurdsson | Engineering Research Institute | Internet: valdi@kerfi.hi.is University of ICELAND | Hjardarhagi 2-6 | Phone: 354-1-694699 107 Reykjavik, ICELAND | ------------------------------------------------------------------------
karl@grebyn.com (Karl A. Nyberg) (03/21/90)
In article <1587@krafla.rhi.hi.is> valdi@rhi.hi.is (Thorvaldur Sigurdsson) writes:
%Problem : Making unix system calls within Ada code
%Background : HP-UX 6.5, HP 9000/300 series, Alsys 4.35 Ada compiler
%Error message :
% ld: Undefined external -
% _ll
% _clear
% ld: output file still contains undefined symbols
% ld: (Warning) did not generate an output file
% ada: Errors detected
%
% "When you want to call an HP-UX system call from Ada
% code, you should use a pragma INTERFACE with C as the
% language name. It is not necassary to provide the C
% object file to the binder, because it will be found
% automatically when the linker searches the system
% library".
%
%Question : Is the manual wrong concerning automatic linking or
% am I doing something wrong in the code ?
%
My guess is you are trying to use not SYSTEM calls, but calls to units in
some particular libraries (e.g. curses?). In those cases, you will need to
include the C object file to the binder (possibly the archive file?) to
resolve those names.
Or, are you trying to use the shell commands "clear" and "ls -l"? In which
case you're asking an entirely different set of questions, for which the
answer is a convoluted use of either the "system" call (if it exists on your
machine) or getting an interface to fork and/or exec.
-- Karl --gallag@hp-and.HP.COM (Mike Gallagher) (03/21/90)
> Problem : Making unix system calls within Ada code > Background : HP-UX 6.5, HP 9000/300 series, Alsys 4.35 Ada compiler > Error message : > ld: Undefined external - > _ll > _clear > ld: output file still contains undefined symbols > ld: (Warning) did not generate an output file > ada: Errors detected > > > procedure MAIN is > > begin > > UNIX_SYSTEM_CALL.clear; > UNIX_SYSTEM_CALL.ll; > > end MAIN; > > > system.ads : The following source is the unix_system_call package > > -- ************************************************ > -- * ABSTRACT: Package specification * > -- ************************************************ > > package UNIX_SYSTEM_CALL is > > procedure clear; > procedure ll; > > private > > pragma INTERFACE (C, clear); -- clear display > pragma INTERFACE (C, ll); -- long list > > end UNIX_SYSTEM_CALL; -- package specification > Using the HP Ada compiler on a HP-UX A.B3.10 U 9000/855 machine, I use the following: with SYSTEM_ENVIRONMENT; procedure MAIN is LOCAL_STATUS : SYSTEM_ENVIRONMENT.EXIT_STATUS; begin LOCAL_STATUS := SYSTEM_ENVIRONMENT.EXEC_SHELL_COMMAND("clear"); LOCAL_STATUS := SYSTEM_ENVIRONMENT.EXEC_SHELL_COMMAND("ll"); end MAIN; Perhaps your compiler has a similar SYSTEM_ENVIRONMENT package. Mike Gallagher gallag@hp-and
defaria@hpclapd.HP.COM (Andy DeFaria) (03/22/90)
This repsonse is a pointer to the notes group comp.lang.ada where a solution to this problem is proposed.