Vladimir's IBM AIX notes

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Various notes on AIX specific topics:

Contents

[edit] Using dbx debugger

  • Start debugger with 
dbx executable

If a core file exists in the current directory, dbx will automatically pick it up and start a post mortem analysis.

  • Pass program arguments to the run command inside dbx: 
(dbx) run --version
  • See the stack trace (gdb bt command) with 
(dbx) where
  • Set a breakpoint to a function with: 
(dbx) stop in processResponse
  • Set a breakpoint to a line number with stop at ["filename":]linenr: 
(dbx) stop at "prima_saml_support.cpp":330
  • Move in the stack with frame 0-n 
(dbx) frame 2
  • Quit the debugger with quit 
(dbx) quit

[edit] Linking dynamic libraries

To test how to make (shared object) libraries:

  • Preliminaries: I have a program (usemylib.c) using a library (mylibfunc.c) with a function (print_hello) advertised in a header file (mylibfunc.h). Compile the program and the library into object files:
  • Link a program with an object file: 
xlc -o usemylib-static-o usemylib.o mylibfunc.o
  • Create a static library, link a program with the library 
ar -rv libmylibfunc-static.a mylibfunc.o
xlc -o usemylib-static-lib usemylib.o -L . -lmylibfunc-static
  • Create a shared object, link a program agains the shared object 
xlc -o mylibfunc-shr.o -qmkshrobj mylibfunc.o
xlc -o usemylib-shr-o usemylib.o mylibfunc-shr.o
export LD_LIBRARY_PATH=.
export LIBPATH=. 
./usemylib-shr-o # needs mylibfunc-shr.o to run
ldd usemylib-shr-o 
>> usemylib-shr-o needs:
        /usr/lib/libc.a(shr.o)
        ./mylibfunc-shr.o
        /unix
        /usr/lib/libcrypt.a(shr.o)
    • Note that even though to run the program, it works to either set LD_LIBRARY_PATH or LIBPATH, ldd only picks LIBPATH and otherwise prints Cannot find for each missing library or object file.
  • Create a shared library - reuse shared object created in previous step 
ar -rv libmylibfunc-shr.a mylibfunc-shr.o
xlc -o usemylib-shr-lib usemylib.o -L . -lmylibfunc-shr
./usemylib-shr-lib # needs libmylibfunc-shr.a
ldd usemylib-shr-lib
>> usemylib-shr-lib needs:
        /usr/lib/libc.a(shr.o)
        ./libmylibfunc-shr.a(mylibfunc-shr.o)
        /unix
        /usr/lib/libcrypt.a(shr.o)
  • Alternatively with makeC++SharedLib: note that this wrapper script creates an Object, not a library - it's an quivalent to creating a shared object two steps above. 
makeC++SharedLib -o mylibfunc-shr-cpp.o -p 0 mylibfunc.o  -L /usr/vac/lib 
xlc -o usemylib-shr-o-cpp usemylib.o mylibfunc-shr-cpp.o

[edit] Running interactive LoadLeveler jobs 

poe ./prog.exe –llfile ./llfile

[edit] Starting sendmail as an AIX service

The startsrc command does not know any default arguments to the service and they must be explicitly passed. For sendmail, this is: 

startsrc -s sendmail -a "-bd -q30m"
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