Use ldd instead of scanelf in install.sh

[exot]

Hey,

I just figured that the install.sh script was not working properly for me, because scanelf is not present on my system. However, the script can easily be changed to work with ldd instead of scanelf like so:

#!/usr/bin/env bash
set -e

which profanity > /dev/null
which ldd > /dev/null
which sed > /dev/null

profanity="$(which profanity)"
python_version="$(ldd "${profanity}" | grep libpython | sed -nre 's/^\s*libpython([0-9]+\.[0-9]+).*$/\1/p')"

python"${python_version}" setup.py install --force --user --prefix=
mkdir -p ~/.local/share/profanity/plugins
cp deploy/prof_omemo_plugin.py ~/.local/share/profanity/plugins/

I do not know whether this works on all systems, but as far as I can see it should.

Best,

  Daniel

[bascht]

Hi Daniel! Thanks for your report. We decided against ldd (see the discussion over here) – if you have any alternative that would be more compatible: we're open for improvements. :smile:

[exot]

Hey bascht,

thanks for the pointer, I didn't know there was a prior discussion on what tool to use to extract the built in python version. (Indeed, I even didn't know know about the security considerations around ldd, shame on me …).

The discussion already provided an alternative (readelf) that I would like to see instead of scanelf, because it's part of the standard installation of virtually every Linux distribution (I don't know about OSX, though). From a quick glance over the discussion, I cannot directly see why this option had been discarded … Do you know why?

The man page of ldd indead also mentions an alternative, namely objdump:

$ objdump -p /usr/bin/profanity | grep libpython | perl -pe 's/.*libpython(\d\.\d).*/\1/'
3.7

objdump should be as ubiquitous as readelf, but again I don't know about OSX. (Come to think of it: BSD does not use ELF, does it?)

In any way: this issue is not that important, I just thought to share the idea of simplifying the install script, not realizing there was some prior discussion already covering it. So feel free to close this issue. :)

Best,

  Daniel

[exot]

Edit: modern BSDs do indeed use ELF.

[yumitsu]

@exot There is no ldd on OSX. More than that, there is no libpython library in linked libraries:

~ λ dyldinfo -dylibs $(command -v profanity)
attributes     dependent dylibs
                /usr/local/opt/glib/lib/libgio-2.0.0.dylib
                /usr/local/opt/glib/lib/libgobject-2.0.0.dylib
                /usr/local/opt/glib/lib/libglib-2.0.0.dylib
                /usr/local/opt/gettext/lib/libintl.8.dylib
                /usr/lib/libcurl.4.dylib
                /System/Library/Frameworks/Python.framework/Versions/2.7/Python
                /usr/local/opt/libotr/lib/libotr.5.dylib
                /usr/local/opt/gpgme/lib/libgpgme.11.dylib
                /usr/local/opt/libassuan/lib/libassuan.0.dylib
                /usr/local/opt/libgpg-error/lib/libgpg-error.0.dylib
                /usr/local/opt/readline/lib/libreadline.8.dylib
                /usr/lib/libncurses.5.4.dylib
                /usr/local/opt/libstrophe/lib/libstrophe.0.dylib
                /usr/lib/libSystem.B.dylib

In fact, I can't understand, why are you trying to fetch python version in that way. Why don't you use pkg-config?

~ λ pkg-config --modversion python3
3.7