RE: Problems with status.

[PATTON, BILLY \(SBCSI\)]

Paul,
  I think you hit the nail on the head with $(EXEC_LOG ) ... || exit $?

I'm going to test now.

Thankyouverymuch :)

> -----Original Message-----
> From: Paul Smith [mailto:address@hidden On Behalf Of Paul D. Smith
> Sent: Thursday, April 13, 2006 3:14 PM
> To: PATTON, BILLY (SBCSI)
> Cc: address@hidden
> Subject: Re: Problems with status.
> 
> 
> %% "PATTON, BILLY \(SBCSI\)" <address@hidden> writes:
> 
>   pb> I may have 10 lines in my command but all are ; \  to 
> make one process.
> 
> Not good.
> 
>   pb> example
>   pb> target :
>   pb>   @for X in variable ; do \
>   pb>     if [ -f $$$$X ] ; then \
>   pb>       $(EXEC_LOG) some_scommand ; \
>   pb>     fi ; \
>   pb>   done ; \
>   pb>   $(DO_SOMETHING) ;\
>   pb>   if [ a = b ] ; then \
>   pb>      bla bla bla ; \
>   pb>   fi 
> 
>   pb> EXEC_LOG is failing but make is continuing to run.  As 
> I understand it
>   pb> the last ; wins.
> 
> To be precise, the exit code from a shell script is the exit 
> code of the
> last command executed in the script.
> 
> Unless you explicitly call exit with a different value.
> 
>   pb> This came to me through the K's of defunct processes.  
> 
>   pb> Do I have to do something like
>   pb>   stat=0; \
>   pb> @for X in xxx ; do \
>   pb>   $(EXEC_LOG) ...
>   pb>   let stat=stat+$?
>   pb> ...
>   pb> fi ; \
>   pb> $$stat
> 
> This won't work.  It will just try to run the command "0" or "1" or
> whatever, which certainly doesn't exist.
> 
>   $ /bin/sh -c 'stat=0; $stat'
>   /bin/sh: 0: command not found
> 
> This is the shell, not Perl.
> 
> 
> Do you really want to continue to run the rest of the command once
> something fails?  If so you'll have to do something similar 
> to what you
> suggest.
> 
> But, if you want to stop as soon as something bad happens you have two
> choices: either exit immediately, or use "set -e" in your 
> shell scripts
> to tell the shell to exit as soon as some command fails (see the
> documentation for your shell to know what this means).
> 
> First example:
> 
>  target :
>        @for X in variable ; do \
>          if [ -f $$$$X ] ; then \
>            $(EXEC_LOG) some_scommand || exit $? ; \
>          fi ; \
>        done ; \
>        $(DO_SOMETHING) || exit $? ; \
>        if [ a = b ] ; then \
>           bla bla bla || exit $? ; \
>        fi
> 
> 
> Second example
> 
>  target :
>        @set -e; \
>         for X in variable ; do \
>          if [ -f $$$$X ] ; then \
>            $(EXEC_LOG) some_scommand ; \
>          fi ; \
>        done ; \
>        $(DO_SOMETHING) ; \
>        if [ a = b ] ; then \
>           bla bla bla ; \
>        fi
> 
> Note that neither of this is effective if your commands are in a
> pipeline and one of them fails:
> 
>     foo | bar | baz
> 
> and "bar" fails... this is very, very hard to deal with in 
> normal Bourne
> shell.
> 
> -- 
> --------------------------------------------------------------
> -----------------
>  Paul D. Smith <address@hidden>          Find some GNU make tips at:
>  http://www.gnu.org                      http://make.paulandlesley.org
>  "Please remain calm...I may be mad, but I am a 
> professional." --Mad Scientist
>