Linux – Potential Issues with Adding /usr/local/[s]bin to Root’s Path

linuxpathrootshellunix

I've noticed that the root account $PATH does not include /usr/local/bin or /usr/local/sbin by default. Are there any potential issues that could arise from adding those directories to the path? If so, what is the best way to make sure your shell finds executables in those directories, without affecting the stability and security of the system?

Best Answer

Make sure that the write permissions on the directories and files are reasonable. You don't want "Other" to be able to write there. File owner and group are also very important. You don't want someone adding or changing something that will be executed under root privileges but that may do something either malicious or have unintended consequences.

Adding those directories to the end of the PATH is safer, but doing that doesn't give you the opportunity to have local overrides of standard utilities. There are pluses and minuses to either approach.

If you leave them out of root's PATH, you can still specify the absolute path explicitly.

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Check this link if you're facing the same problem.

Default configuration file depends on which shell you're using. Back to my question, I forgot to check ~/.zprofile("waterwood" is set in this file).

Linux – cron apparently requires a newline character on its own line at the end of the file

Is this a bug?

No. I created a file with no newline character at the end. Nevertheless Vim (after :set list) shows $ at the end. It looks like your premise is false, your file is missing a final newline, cron works as intended.

Notes:

POSIX requires a trailing newline character to consider any line to be complete.

3.195 Incomplete Line
A sequence of one or more non-<newline> characters at the end of the file.

[…]

3.206 Line
A sequence of zero or more non-<newline> characters plus a terminating <newline> character.

So the behavior of cron is not just an arbitrary quirk (although the tool might not be that restrictive). For more insight see Why should text files end with a newline?
Vim with default settings will fix the missing newline while saving, unless you tell it not to.
To tell whether there is a newline character at the end or not, make a hexdump of the file, e.g. hexdump the_file or xxd the_file. In case of your crontab this may be hard. In my Debian the crontab is /var/spool/cron/crontabs/kamil, but since I have no access to /var/spool/cron/crontabs/ as a normal user, I cannot just xxd the file. To overcome this I can use the following trick:
```
EDITOR=xxd crontab -e
```
There is a newline at the end iff the last byte reports as 0a.

Best Answer

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