On Friday 12 November 2021 13:38:48 Greg Wooledge wrote: > On Fri, Nov 12, 2021 at 08:19:15AM -0500, Gene Heskett wrote: > > On Friday 12 November 2021 07:36:01 Eduardo M KALINOWSKI wrote: > > > On 12/11/2021 09:30, Stephen P. Molnar wrote: > > > > This is the immediate problem that I need to fix: > > > > > > > > comp@AbNormal:~$ sudo apt upgrade > > > > Reading package lists... Done > > > > Building dependency tree > > > > Reading state information... Done > > > > E: The package brscan4 needs to be reinstalled, but I can't find > > > > an archive for it. > > > > > > > > sudo apt update ran without any problems. > > > > > > Try downloading it again (since it's not part of the archives, it > > > must be downloaded manually) and running 'apt install > > > ./brscan4-......deb' (substituting the actual file name, > > > naturally). The './' is necessary to tell apt it's a file name. > > > > No, to be precise, it tells the file system its a file in the > > currently cd'd to directory. Which may not be in the env's $PATH. > > It's both, Gene. > > To the file system (kernel), ./foo is a relative pathname that's 100% > equivalent to foo. There's no difference at all. > > However, to apt-get or apt, ./foo and foo are very different > arguments. The former is a relative path to a file, and the latter is > a package name. > > This has nothing to do with $PATH, because we're not talking about > running a program from the current directory. We're talking about > apt-get and apt specifically. > > You're thinking of the conventional use of "./configure" and so on to > run a program in the current directory. This is necessary because > PATH should never contain "." (or the empty string) as one of its > components. That would allow the execution of *anything* at all in > the current directory (the way MS-DOS works). This is a huge security > problem on a multi-user system, where someone could leave a script in > /tmp hoping for you to run it accidentally. > > It *works* because the shell bypasses the PATH search if the command > that you give it contains a slash character. ./configure means "run > the program named configure in the current directory, and don't search > anywhere else".
Thanks Greg, a better view than mine. Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene>
