Reclaiming the lost art of Linux server administration

Post by ugjka » Fri, Jan 28, 2022, 7:01 PM UTC

trabant00 wrote: post #19

VWWHFSfQ wrote: post #12

Regular SA and DBA jobs will be almost completely gone within a decade or so. Same as there are hardly any auto mechanics anymore because nobody can fix any of the new cars but the manufacturer. You'll only find those jobs at one of the handful of cloud companies. Nobody will know how to do anything for themselves anymore and all this experience and knowledge will be lost. There are no more actual administrators. Jus…

I've been hearing this for the past 20 years. And now my sysadmin skills are more and more in demand. For the past 5 years or so I started making more money than a dev because of supply and demand. Rent to AWS actually drives demand up quite a lot since the bills are huge and very few people understand what is under the hood and how it can be optimized. I doubt very much things will change in the near future. In the…

Post by massysett » Fri, Jan 28, 2022, 7:02 PM UTC

netr0ute wrote: post #9

cure wrote: post #4

Earlier quoted context omitted.

> That advice can cause substantial headache on Ubuntu/Debian, where the Almquist shell is /bin/sh. This does not implement much of bash and will fail spectacularly on the simplest of scripts. This is also an issue on systems using Busybox. At least for Debian and Ubuntu, that's why we start bash scripts with #!/bin/bash, of course. Your point is valid for Busybox, though.

Why would anyone want to target bash specifically which doesn't exist in all systems instead of just sticking to what's implemented in /bin/sh?

Post by chasil » Fri, Jan 28, 2022, 7:04 PM UTC

ericbarrett wrote: post #15

chasil wrote: post #6

Earlier quoted context omitted.

> that's why we start bash scripts with #!/bin/bash That will also fail spectacularly, as bash does not behave the same when called as /bin/bash as it does when it is /bin/sh. I have principally noticed that aliases are not expanded in scripts unless a shopt is issued, which violates POSIX. Forcing POSIXLY_CORRECT might also help.

Not sure what you are saying, bash behaves as bash when invoked as /bin/bash, and Bourne-shell-ish when invoked as /bin/sh. Lots more detail in the man page. I've never seen use of aliases in a bash script...? They are generally for CLI convenience.

  $ ll /bin/sh
  lrwxrwxrwx. 1 root root 4 Nov 24 08:40 /bin/sh -> bash

  $ cat s1
  #!/bin/sh
  alias p=printf
  p hello\\n

  $ cat s2
  #!/bin/bash
  alias p=printf
  p world\\n

  $ ./s1
  hello

  $ ./s2
  ./s2: line 3: p: command not found

Post by chungy » Fri, Jan 28, 2022, 7:05 PM UTC

NexRebular wrote: post #14

zokier wrote: post #5

Earlier quoted context omitted.

> That advice can cause substantial headache on Ubuntu/Debian, where the Almquist shell is /bin/sh. This does not implement much of bash and will fail spectacularly on the simplest of scripts. That's not really a problem as long as you use #!/bin/bash shebang, and there is nothing wrong in doing that.

Unless bash lives in /usr/local/bin/bash

Post by tester756 » Fri, Jan 28, 2022, 7:06 PM UTC

VWWHFSfQ wrote: post #12

Regular SA and DBA jobs will be almost completely gone within a decade or so. Same as there are hardly any auto mechanics anymore because nobody can fix any of the new cars but the manufacturer. You'll only find those jobs at one of the handful of cloud companies. Nobody will know how to do anything for themselves anymore and all this experience and knowledge will be lost. There are no more actual administrators. Jus…