Bug 587428

sysconfig package -> Marius

AFAICS the script /etc/init.d/network is a bash script and also the
file /etc/sysconfig/network/scripts/functions is for bash usage only.

The constructs '<()' and `>()' are so called fifo's explained in the
manual page of the bash in section `Process Substitution'

       Process substitution is supported on systems that support named pipes
       (FIFOs) or the /dev/fd method of naming open  files.   It  takes  the
       form  of  <(list) or >(list).  The process list is run with its input
       or output connected to a FIFO or some file in /dev/fd.  The  name  of
       this  file  is  passed  as  an argument to the current command as the
       result of the expansion.  If the >(list) form is used, writing to the
       file  will  provide input for list.  If the <(list) form is used, the
       file passed as an argument should be read to  obtain  the  output  of
       list.

       When available, process substitution is performed simultaneously with
       parameter and variable expansion, command  substitution,  and  arith-
       metic expansion.

Please note that the construct

     a=""
     while do ... a=x;... done < <(command)
     echo $a

is able to to show the new value of $a whereas the

    a=""
    command | while do ... a=x;... done

does not. Beside this the first way of using a real fifo is
normally faster then using a normal pipe.

Seidemark, the construct <() or ()> can be replaced by

   mkfifo /tmp/myfifo || exit 1
   command > /tmp/xxx &
   while do ... done < /tmp/xxx
   rm -f /tmp/xxx

or to be more secure and use only program from the root fs:

  trap 'rm -f $fifo' EXIT
  fifo=$(mktemp -u fifo.XXXXXXXX) || exit 1
  mknod $fifo p || exit 1
  command >  $fifo &
  while do ... done < /tmp/xxx

the script /etc/sysconfig/network/scripts/functions could
use a switch on $0 to distinguish between `sh' and `bash'

Thanks Werner,
you were faster. I'm not even thinking about sh compatibility -- there
is no reason for and also IMO no reason to reinvent the wheel and use
sh-compatible code as in comment 3.

(In reply to comment #0)
> User-Agent:       Mozilla/5.0 (compatible; Konqueror/4.3; Linux) KHTML/4.3.5
> (like Gecko) SUSE
> 
> It appears to me that
> 
>  /etc/sysconfig/network/scripts/functions
> 
> is not /bin/sh compatible.

> I'm not sure if  it is /bin/bash but would doubt it too.

It _is_ bash and no, it isn't sh compatible.

All scripts in sysconfig require bash and they use #!/bin/bash at
the begin. BTW: Most of the scripts in openSUSE require bash.

I'll also not change to become sh compatible. There is no reason for
use and it would require that some features can't be used any more,
e.g. regex - it makes completely no sense to reinvent the wheel.

This special example is maybe not needed in sysconfig, but it is
possible in bash >= 3.x:

pat='^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)([?]([^#]*))?(#(.*))?'
str='https://bugzilla.novell.com/show_bug.cgi?id=587428#add_comment'
if [[ $str =~ $pat ]] ; then
  declare -i i
  for ((i=0;i<${#BASH_REMATCH[@]};i++)) ; do
    echo "[$i] ${BASH_REMATCH[$i]}"
  done
fi
[0] https://bugzilla.novell.com/show_bug.cgi?id=587428#add_comment
[1] https:
[2] https
[3] //bugzilla.novell.com
[4] bugzilla.novell.com
[5] /show_bug.cgi
[6] ?id=587428
[7] id=587428
[8] #add_comment
[9] add_comment

[...]
> I would say a shell-construct like 
> 
> while ..
> 
> do < <(command)
> 
> is not allowded. 
> better use

See "man bash", "Process Substitution". It is normal bash syntax,
that opens a fifo `<()' as normal standard input for all command
in the while loop.

> I think that most of network-script is working is that these>
> functions are not used in many cases.

Sorry, but this is nonsense.

> A pool of computers did not start network due to this error.

Then don't try to use /bin/sh when a script is using /bin/bash
at the begin.


> Please rethink also programming-style of 
> 
> /etc/init.d/network 
> 
> Code around line 49: 
> 
> if ! . scripts/functions 2>/dev/null; then
>         echo -n "Network: file /etc/sysconfig/network/scripts/functions is
> missing."
>         rc_failed
>         rc_status -v
>         rc_exit
> fi
> 
> I my case scripts/functions was present, but had a syntactical error but
> shell-output of that error was redirected to /dev/null. The resulting message
> "Network: file /etc/sysconfig/network/scripts/functions is missing." was not
> true and misleading.

Yes, the message is misleading - most of the scripts are quite old,
written by many people having different styles and could get some
some cleanup. I'll fix the above when I not forget it, but there
are more urgent things to cleanup than the above message.

And no, there is no syntax error. Every script in sysconfig verified
for correct syntax (bash -n) in every RPM build.

=> INVALID, try to use wrong shell.

*** Bug 739338 has been marked as a duplicate of this bug. ***