[systemd-devel] [RFC PATCH] Fix so install will work without 'ln --relative' support

[Kay Sievers]

On Fri, May 16, 2014 at 12:30 AM, Lennart Poettering
<lennart at poettering.net> wrote:
> On Wed, 07.05.14 08:54, Emil Sjölin (emil.sjolin at axis.com) wrote:
>
>> This fix makes sure that the package installation will work
>> on systems using versions of 'GNU coreutils' older than 8.16.
>>
>> Please see tools/lnr.sh for limitations for this fix.
>> ---
>>  configure.ac |   16 ++++++++++
>>  tools/lnr.sh |   93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 109 insertions(+)
>>  create mode 100755 tools/lnr.sh
>>
>> diff --git a/configure.ac b/configure.ac
>> index ead697b..399a52f 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -315,6 +315,22 @@ fi
>>  AM_CONDITIONAL(ENABLE_COVERAGE, [test "$have_coverage" = "yes"])
>>
>>  # ------------------------------------------------------------------------------
>> +ln_relative_support=yes
>> +AC_CHECK_PROG(ln_found, [ln], [yes], [no])
>> +if test "x$ln_found" = xno ; then
>> +        AC_MSG_ERROR([*** ln support requested but the program was not found])
>> +else
>> +        ln_version_major="`ln --version | head -1 | cut -d ' ' -f 4 | cut -d '.' -f 1`"
>> +        ln_version_minor="`ln --version | head -1 | cut -d ' ' -f 4 |
>> cut -d '.' -f 2`"
>
> Isn't "head -n 1" more correct?
>
>> +        if test "$ln_version_major" -lt 8 || test "$ln_version_major" -eq 8 -a "$ln_version_minor" -lt 16; then
>> +                ln_relative_support=no
>> +        fi
>> +        if test "x$ln_relative_support" = "xno"; then
>> +                LN_S=$(echo "$LN_S" | sed
>> s:"ln":""$srcdir"\/tools\/lnr.sh":)
>
> Shouldn't this be "sed -e"?
>
>> +        fi
>> +fi
>
> Hmm, if we ship this anyway, why not always use it? Otherwise it would
> too easily bitrot...
>
> THis would also allow removing much of the shell pipeline in the
> configure script for this. I mean, these commands have changed all the
> time in the past, for example sed quite a bit...
>
>> +
>> +# ------------------------------------------------------------------------------
>>  have_kmod=no
>>  AC_ARG_ENABLE(kmod, AS_HELP_STRING([--disable-kmod], [disable loadable modules support]))
>>  if test "x$enable_kmod" != "xno"; then
>> diff --git a/tools/lnr.sh b/tools/lnr.sh
>> new file mode 100755
>> index 0000000..74e1644
>> --- /dev/null
>> +++ b/tools/lnr.sh
>> @@ -0,0 +1,93 @@
>
> No shebang?
>
>> +# This script makes the 'ln --relative' command work as expected on a system where the
>> +# 'relative' option of 'ln' is not supported.
>> +#
>> +# NOTE:
>> +# The script assumes that the 'relative' option of 'ln' is used with any
>> +# of the following syntaxes:
>> +# '--relative'
>> +# '-r'
>> +#
>> +# The script will NOT handle combined options e.g. '-rf', '-ir' etc.
>> +# The script will also only handle the 1st form of the 'ln' command (see man page
>> +# for the 'ln' command for the different forms).
>> +#
>> +
>> +
>> +while [ $# -gt 2 ]; do
>> +     string="$1"
>> +     if [ "${string#-*}" != "$string" ]; then
>> +             # argument is an option
>> +             if [ "$string" = "$relop_1" ] || [ "$string" =
>> "$relop_2" ]; then
>
> Why not "-o" instead of "] || ["?
>
> I'd really prefer if somebody who's a true shell guru could look over
> this. Harald? (Or Zbigniew?)

I do not think we should do such hacks in upstream systemd.

It is a commonly available feature since quite some years, and
building without chroot on old systems is a bit too exotic to justify
carrying this rather large work around upstream.

We do not accept distro-specific, not commonly needed things in the
upstream code base because we do not want to maintain them, the same
seems to apply to this.

Thanks,
Kay