5 ms·

I've been using linux since 1992 and if there's one thing I can't stress enough is to use full directories and not anything abbreviated. After 25 years, I still

I've been using linux since 1992 and if there's one thing I can't stress enough is to use full directories and not anything abbreviated. After 25 years, I still find myself slipping up, overlooking some minute detail, causing data loss.

mmphosis 9y ago
I've heard this suggestion to use full paths for a long time. Why use full paths?
- tyingq 9y ago
  I'm sure there are other reasons, but the big one is that your scripts may get called in an environment other than your normal logged in shell. Cron, for example, doesn't have the same $PATH as your login shell. So no full paths means you can fail to run some commands, or run the wrong copy of one. There's also the security aspect. If your script has "." in it's $PATH, or something else writeable, I may be able to coerce it to run an imposter command.
  - uhhfcuvv 9y ago
    This is terrible advice, if you expect your PATH to be something, just set it at the top of the script and be done with it. No need to make it 100 times harder to read.
    - yebyen 9y ago
      Why even expect binaries to be in the same place on different systems with different default PATHs? Know how many times I've seen problems caused by (#!/usr/bin/bash|#!/bin/bash) pointing to the wrong place? After reading this thread though, I'm not sure I want to suggest people write `#!/usr/bin/env bash` either... since that depends on the path being correctly set, and bash being in the path!
      - mobilethrow 9y ago
        I've started to dislike /usr/bin/env too. At least use -i. Otherwise you're one PATH manipulation away from executing a malicious program as your intended shell.
    - tyingq 9y ago
      A PATH, though, is global. Situations exist where you need more granularity. There's also things like "watch" and "at" you might use in a shell script. They don't inherit the parent's environment, so setting PATH doesn't help. You're correct in that "full paths" isn't a definitive answer though. I suppose the more generic advice to not depend on your environment to have it right is better.
ori_b 9y ago
I use a variety of operating systems, many of which put things in different locations. Hell, even across linuxes, locations differ. Don't do this. $PATH exists for a reason.

mmphosis 9y ago

I've heard this suggestion to use full paths for a long time. Why use full paths?

tyingq 9y ago
I'm sure there are other reasons, but the big one is that your scripts may get called in an environment other than your normal logged in shell. Cron, for example, doesn't have the same $PATH as your login shell. So no full paths means you can fail to run some commands, or run the wrong copy of one. There's also the security aspect. If your script has "." in it's $PATH, or something else writeable, I may be able to coerce it to run an imposter command.
- uhhfcuvv 9y ago
  This is terrible advice, if you expect your PATH to be something, just set it at the top of the script and be done with it. No need to make it 100 times harder to read.
  - yebyen 9y ago
    Why even expect binaries to be in the same place on different systems with different default PATHs? Know how many times I've seen problems caused by (#!/usr/bin/bash|#!/bin/bash) pointing to the wrong place? After reading this thread though, I'm not sure I want to suggest people write `#!/usr/bin/env bash` either... since that depends on the path being correctly set, and bash being in the path!
    - mobilethrow 9y ago
      I've started to dislike /usr/bin/env too. At least use -i. Otherwise you're one PATH manipulation away from executing a malicious program as your intended shell.
  - tyingq 9y ago
    A PATH, though, is global. Situations exist where you need more granularity. There's also things like "watch" and "at" you might use in a shell script. They don't inherit the parent's environment, so setting PATH doesn't help. You're correct in that "full paths" isn't a definitive answer though. I suppose the more generic advice to not depend on your environment to have it right is better.

ori_b 9y ago

I use a variety of operating systems, many of which put things in different locations. Hell, even across linuxes, locations differ. Don't do this. $PATH exists for a reason.