On Thu, 18 Mar 2021 22:17:07 +0100
Pierre Labastie <pierre.labas...@neuf.fr> wrote:

> On Thu, 2021-03-18 at 14:32 -0400, Scott Andrews wrote:
> > On Thu, 18 Mar 2021 11:51:09 -0500
> > Bruce Dubbs <bruce.du...@gmail.com> wrote:
> >   
> > > On 3/18/21 11:21 AM, Scott Andrews wrote:  
> > > > 
> > > > I am presently looking at and working on the LFS boot scripts.
> > > > They are in my opinion very rough state.
> > > > 
> > > > I am going to clean them up and use the following format for
> > > > all of the individual scripts that will be used on my systems
> > > > as follows:
> > > > 
> > > > Shebang line:           #!/bin/bash
> > > > Comment Title block:    the purpose of the script
> > > > Global variables:       defined here
> > > > Local variables:        not defined in functions
> > > > Source scripts:         all outside scripts sourced here
> > > > Functions:              all functions defined here
> > > > Mainline:               main body
> > > > Cleanup:                any cleanup that needs to be done
> > > > Exit:                   script terminates
> > > > 
> > > > I will add comments to explain the goal/purpose of the script
> > > > and also what each function does. I am going to rewrite some
> > > > of the scripts so they will be self sufficient as possible.
> > > > 
> > > > I will add ipv6 support using a service file much like
> > > > ivp4-static. This should allow ipv6 to be used on both dual
> > > > stacked systems and system that are ipv4 or ipv6 only.
> > > > 
> > > > I am also going to build to test them before placing them
> > > > onto my working servers.
> > > > 
> > > > Is there any interest by LFS on doing this or am I just
> > > > wasting my time posting here?    
> > > 
> > > What you propose seems to be mostly documentation, but other
> > > changes may be appropriate.  I suggest you do a couple and let
> > > us review them. Then, with constructive feedback, the rest of
> > > the LFS scripts.
> > > 
> > > I'll note though that you are the only one giving feedback and
> > > the scripts have only had minor changes since at least 2011.  
> > 
> > example follows.........  
> 
> Some shell style comments:
> > 
> > remove SCRIPT_STAT from init-functions
> > 
> > Correctly write check_script_status in rc
> > 
> > function check_script_status {
> >         local script=${1}  
> It's preferable to use quotes around any variable you do not know
> in advance: script="$1"
> 
> >         SCRIPT_STAT="0"  
> But here it is not needed: SCRIPT_STAT=0

Actually it is very much needed, as the variable is only used in the
rc script and it is only used as a "status".  You are mis reading the
intent.

> 
> >         if [ ! -f ${script} ]; then  
> Same here. Moreover, if script is empty, you'll get an error: 
> if [ ! -f "${script}" ]; then
> 
> >                 log_warning_msg "${script} is not a valid file."
> >                 SCRIPT_STAT=retval="1"  
> =1. Note that "echo $SCRIPT_STAT" would print "retval=1", and that
> retval is empty after this statement. Is it what you want?
> Shouldn't there be an exit or return here? If $script is not a
> file, there is little chance it is executable.

See my response to bruce

> 
> >         fi
> >         if [ ! -x ${script} ]; then  
> if [ ! -x "${script}" ]; then ...
> 
> >                 log_warning "${script} is not executable."
> >                 SCRIPT_STAT=retval="1"  
> =1, and same note as above.
> >         fi
> >         return
> > }
> > 
> > #       Check script for file and executable
> > check_script_status
> > if [ "1" = ${SCRIPT_STAT} ]; then continue; fi  
> You'd better quote ${SCRIPT_STAT} instead of 1. And, as said above,
> SCRIPT_STAT may contain "retval=1".
> 

I could point out the lack of quoting in the existing boot scripts
but I found that to not be necessary. 

> 
> > 
> > That fixes the issue but I would rewrite check_script_status to
> > return true or false then then do this
> > 
> > function check_script_status {
> >         local script=${1}
> >         local retval="0"
> >         if [ ! -f ${script} ]; then
> >                 log_warning_msg "${script} is not a valid file."
> >                 retval="1"
> >         fi
> >         if [ ! -x ${script} ]; then
> >                 log_warning "${script} is not executable."
> >                 retval="1"
> >         fi
> >         [ "0" = ${retval} ] && return 0 || return 1  
> Why not `return retval'?
> 
> > }
> > 
> > if [ check_script_status ]; then continue; fi  
> No brackets here. Brackets introduce predicates like -f, -x, or
> (in)equality. Testing the return of a command (a function here) is
> just done with `if <command>'. Note that `if [ check_script_status
> = 0 ]' wouldn't work either.
> 
> Also, it seems to me that the logic would be `if !
> check_script_status; then continue; fi'

So when you are going to cleanup the boot scripts as they use 

if [ something ]; then whatever; fi

and

if something; then whatever; fi


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