Hi Jan, all, I'd like to carry our OBS dicussion to a wider audience (https://build.opensuse.org/request/show/672510). The question is whether we can assume that "/bin/sh" links to bash, in particular whether rpm scriptlets without explicit -p interpreter can be assumed to interpreted by bash. I'm aware that, in principle, /bin/sh is supposed to be the Bourne shell on Unix systems. But as a matter of fact, on current openSUSE, it is not. Unless it's tampered with, /bin/sh is a symlink to /bin/bash. bash is not started in full POSIX mode if invoked as /bin/sh, and even if it's in POSIX mode, it supports some extensions over the POSIX shell spec (e.g. the [[ ]] construct), which makes it behave differently than another shell not supporting [[ ]] would (*). Problably there are more differences, I can't claim to know them all. Here are some arguments why I think it'd be reasonable to assume that /bin/sh is bash on openSUSE: 1. patterns-base-minimal_base depends on bash, and the /bin/sh symlink is a non-configurable part of the "bash" package. 2. we could handle /bin/sh via /etc/alternatives, but we don't. 3. our Wiki suggests testing failing scriplets using "bash -xv" (https://en.opensuse.org/openSUSE:Packaging_scriptlet_snippets) 4. /bin/sh has pointed to bash for a long time (not sure how long exactly). FTR, Fedora basically guarantees (sh == bash) for the purpose of rpm scriptlets (https://fedoraproject.org/wiki/Packaging:Scriptlets). So Fedora <-> openSUSE portability may also be an issue to consider. If we can't assume that /bin/sh is bash, what else can we assume? I recall from earlier work that writing really 100% compatible shell code for all kinds of environments is really hard. E.g., "[" isn't 100% portable either, even though it's part of the POSIX "test" standard (http://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html). We should have clear rules which syntax expressions can be used in rpm scriptlets, and which can't. IMO we should define one of the various existing shells as a reference by saying "if it's supported by this shell, it's valid scriptlet code". That'd be easier (especially for testing compliance) than referring to a spec. That reference shell doesn't have to be bash, of course. Thanks Martin (*) For example: # ln -s /usr/bin/echo '/usr/bin/[[' # ls -l /bin/sh lrwxrwxrwx 1 root root 4 Feb 8 10:38 /bin/sh -> bash # /bin/sh --posix -c '[[ 2 = 1 ]] && echo yes' # dash -c '[[ 2 = 1 ]] && echo yes' 2 -eq 1 ]] yes -- Dr. Martin Wilck <mwilck@suse.com>, Tel. +49 (0)911 74053 2107 SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org