Re: [PATCH 1/4] scripts/run-qemu.sh: better error checks & formatting

[Demi Marie Obenour <demiobenour@gmail.com>]

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On 11/13/25 07:23, Alyssa Ross wrote:
> Demi Marie Obenour <demiobenour@gmail.com> writes:
> 
>> No other functional change intended.
>>
>> Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
>> ---
>>  scripts/run-qemu.sh | 24 ++++++++++++++----------
>>  1 file changed, 14 insertions(+), 10 deletions(-)
> 
> This is a lot of changes all in one, without individual explanation.
> I'd appreciate it if they could be broken up and explained, because I'm
> going to have to ask what the purpose of each change is.
> 
>> diff --git a/scripts/run-qemu.sh b/scripts/run-qemu.sh
>> index 64fd29259ab108bc547cb7c74623ae9dc288b3b7..9c6c8193bbeba5916038c82d8f76992051719c19 100755
>> --- a/scripts/run-qemu.sh
>> +++ b/scripts/run-qemu.sh
>> @@ -1,11 +1,15 @@
>> -#!/bin/sh -ue
>> +#!/bin/sh --
> 
> The idea here is to be robust against the script being invoked with
> argv[0] set to "-c" or something?

Correct.

>>  # SPDX-FileCopyrightText: 2023-2025 Alyssa Ross <hi@alyssa.is>
>>  # SPDX-License-Identifier: EUPL-1.2+
>>  
>>  # This script wraps around QEMU to paper over platform differences,
>>  # which can't be handled portably in Make language.
>> +set -uef
> 
> Adding -f makes sense.
> 
>> +if [ -n ${ARCH+test} ]; then
>> +	ARCH=$(uname -m)
>> +fi
>>  
>> -case "${ARCH:="$(uname -m)"}" in
>> +case $ARCH in
>>  	aarch64)
>>  		machine=virt,accel=kvm:tcg,gic-version=3,iommu=smmuv3
>>  		;;
> 
> Why is this better?

If uname exits with a non-zero status, the script will exit rather
than continuing.

>> @@ -17,13 +21,13 @@ case "${ARCH:="$(uname -m)"}" in
>>  esac
>>  
>>  i=0
>> -while [ $i -lt $# ]; do
>> -	arg="$1"
>> +while [ "$i" -lt "$#" ]; do
>> +	arg=$1
>>  	shift
>>  
>> -	case "$arg" in
>> +	case $arg in
>>  		-append)
> 
> Makes sense as long as we're consistent about it.  I wonder if we could
> get the formatter to do this.

+1

>> -			set -- "$@" -append "${append:+$append }$1"
>> +			set -- "$@" -append ${append:+"$append "}"$1"
>>  			i=$((i + 2))
>>  			shift
>>  			continue
> 
> Don't understand this one.  We've gone from one set of quotes to two
> sequential ones.

I remember reading that the first version might not conform to POSIX.
I'm not sure if it matters though.
-- 
Sincerely,
Demi Marie Obenour (she/her/hers)

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