CoCoA » CoCoALib

I agree the CoCoA scripts should consistently use only one of the shebang options. I think either option has a potential disadvantage against the other and by mixing them, one inherits the union of the disadvantages.

(As an advantage of the env option, one might add that it allows the user to use a different version of the shell easily, e.g. should the one in /bin be nonexistent, buggy or otherwise unsuitable. But that may not be a major point here.)

John Abbott wrote:

Ulrich perfectly reasonably called cat and rm in the script. I have changed these to
/bin/rm and /bin/cat to avoid the possibilities of "impostors". Obviously if /bin/rm
or /bin/cat do not exist then an error will be triggered. Is there any modern linux/unix-like
platform where such an error would be forthcoming? If so, how do we work around it?

I'm not sure I understand the argument for providing full paths to cat and rm in detail. Wouldn't the same argument apply to make and qmake (which are called in the same script)? And also to several other commands, e.g., g++ (see CXX=g++ in the configure script)?

Is there some standard (POSIX ?) you would generally assume a user's system to conform to? In POSIX it seems cat, rm, and make may be expected to behave reasonably, but /bin is not among the directories guaranteed to exist.

On a more practical note, perhaps the following shebang line provides the behavior that you want (without warranty or encouragement!):

#!/usr/bin/env -S PATH=/what/you:/want /bin/bash

It is however less portable than either of the above options (in particular, env -S doesn't work e.g. with OpenBSD env, but BSDs don't seem to be in your focus anyway).

Also it assumes the script to provide a set of paths that works across all targeted systems.

On the other hand, where it works it allows execution of programs only from a set of prescribed paths while still allowing the system to choose the path from that set for each program.