> From: Kiszka, Jan (FT RPD CED) <[email protected]>
> Sent: Friday, November 21, 2025 11:16
> Subject: Re: [PATCH 1/1] scripts: Changed potential O(n) file size
> calculation to
> O(1)
>
> > scripts/mkemmc.sh | 10 ++++++++--
> > 1 file changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/scripts/mkemmc.sh b/scripts/mkemmc.sh index
> > 45dc3f08fa..d2c4e84b16 100755
> > --- a/scripts/mkemmc.sh
> > +++ b/scripts/mkemmc.sh
> > @@ -37,13 +37,19 @@ usage() {
> > exit "$1"
> > }
> >
> > +file_size() {
> > + ls_line=$(ls -Hdog "$1") || return
>
> This will not suppress the error message when a file does not exist or is not
> accessible, so:
>
> ls_line=$(ls -Hdog "$1" 2>/dev/null) || return
My take on this is:
`ls' is able to produce informative diagnostic messages as it has
access to `errno'. The additional information, e.g., whether an 'EACCES',
an `ENOENT' or an `ENOTDIR' error has occurred, should in the majority
of cases help the user in fixing the underlying problem. I think it would be
counter-productive to suppress this.
(In fact, one could go further and consider using only the error message
of `ls' and not provide an own error message at all.
In this case, it would be especially easy to return `ls' status back to
the script's invoker, by simply invoking `exit' without an argument.)
>
> > + printf %s\\n "$ls_line" | cut -d\ -f3
> > + unset ls_line
> > +}
> > +
> > process_size() {
> > name=$1
> > image_file=$2
> > alignment=$3
> > image_arg=$4
> > if [ "${image_arg#*:}" = "$image_arg" ]; then
> > - if ! size=$(wc -c < "$image_file" 2>/dev/null); then
> > + if ! size=$(file_size "$image_file"); then
> > echo "Missing $name image '$image_file'." >&2
> > exit 1
> > fi
> > @@ -105,7 +111,7 @@ check_truncation() {
> > if [ "$image_file" = "/dev/zero" ]; then
> > return
> > fi
> > - if ! actual_size=$(wc -c < "$image_file" 2>/dev/null); then
> > + if ! actual_size=$(file_size "$image_file"); then
> > echo "Missing image '$image_file'." >&2
> > exit 1
> > fi
>
> Thanks,
> Jan
>
> --
> Siemens AG, Foundational Technologies
> Linux Expert Center
