Re: failure in pipeline not reflected in $?

[Jason Pepas]

Thanks!  Sorry to waste your time with something which was in the man
page afterall.  This is exactly what I was looking for.

-jason pepas

On Thu, Aug 25, 2005 at 02:02:40AM -0400, Chris F.A. Johnson wrote:
> On Wed, 24 Aug 2005 cell@ices.utexas.edu wrote:
> >
> >Configuration Information [Automatically generated, do not change]:
> >Machine: i586
> >OS: linux-gnu
> >Compiler: gcc
> >Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i586' 
> >-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i586-mandrake-linux-gnu' 
> >-DCONF_VENDOR='mandrake' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' 
> >-DSHELL -DHAVE_CONFIG_H  -I.  -I.. -I../include -I../lib  -D_GNU_SOURCE  
> >-O2 -fomit-frame-pointer -pipe -march=i586 -mtune=pentiumpro
> >uname output: Linux block.ices.utexas.edu 2.6.11-6mdk #1 Tue Mar 22 
> >16:04:32 CET 2005 i686 AMD Athlon(TM) XP 2200+ unknown GNU/Linux
> >Machine Type: i586-mandrake-linux-gnu
> >
> >Bash Version: 3.0
> >Patch Level: 16
> >Release Status: release
> >
> >Description:
> >     I am not sure if this is a bug, or if this is correct behavior.
> >
> >   consider:
> >
> >   false | true
> >   echo $?
> >   0
> >
> >   If a command in a pipeline of commands fails, there appears to be no
> >   way of knowing this.  One alternate behavior to consider is to return
> >   the exit status of the first command in the pipeline to exit with non
> >   zero status.
> 
>     The return codes are stored in the PIPESTATUS array:
> 
> $ false | true | false | true
> $ printf "%s\n" "${PIPESTATUS[@]}"
> 1
> 0
> 1
> 0
> 
> 
> -- 
>     Chris F.A. Johnson                     <http://cfaj.freeshell.org>
>     ==================================================================
>     Shell Scripting Recipes: A Problem-Solution Approach, 2005, Apress
>     <http://www.torfree.net/~chris/books/cfaj/ssr.html>