[SOLVED] i am trying to give the world permission to read and write but it seems to never work

Skaperen · 08-13-2022, 09:58 PM

i am trying to give the world permission to read and write but it seems to never work.

Code:

lt1a/phil/3 /home/phil 28> ls -dl /tmp/p
-rw----rw- 1 root root 25 Aug 13 22:49 /tmp/p
lt1a/phil/3 /home/phil 29> cat /tmp/p
cat: /tmp/p: Permission denied
lt1a/phil/3 /home/phil 30>

rkelsen · 08-13-2022, 11:07 PM

There are no group permissions set.

You need to set them too.

GazL · 08-14-2022, 03:53 AM

Quote:

Originally Posted by rkelsen

There are no group permissions set.

You need to set them too.

That should only be significant if the executing user, which looks to be "phil", is in the "root" group¹.

___
1) which is possible, but would not be the best idea.

teckk · 08-14-2022, 10:33 AM

Code:

__touch /tmp/p.txt

__ls -l /tmp/p.txt
-rw-r--r-- 1 me me 0 Aug 14 10:19 /tmp/p.txt

__chmod 666 /tmp/p.txt 

__ls -l /tmp/p.txt
-rw-rw-rw- 1 me me 0 Aug 14 10:19 /tmp/p.txt

echo "Hello" > /tmp/p.txt

cat /tmp/p.txt
Hello

__sudo chown root:root /tmp/p.txt

__ls -l /tmp/p.txt
-rw-rw-rw- 1 root root 6 Aug 14 10:22 /tmp/p.txt

cat /tmp/p.txt
Hello

Sorry, had to add underscores to be able to post.

boughtonp · 08-14-2022, 10:43 AM

Quote:

Originally Posted by teckk

Sorry, had to add underscores to be able to post.

That's due to LQ's stupid CloudFlare filters picking up on the "\nls -l" within your post.

An easier workaround - which still maintains valid syntax - is to either add a space or backslash before "ls", or put a different option before the "l" param.

dugan · 08-14-2022, 11:10 AM

Is there a umask taking away the permissions?

pan64 · 08-14-2022, 11:12 AM

theoretically it may depend on the permissions of the directory /tmp (and also of /), but we don't know them.

scasey · 08-14-2022, 11:15 AM

Quote:

Originally Posted by Skaperen

i am trying to give the world permission to read and write but it seems to never work.

Code:

lt1a/phil/3 /home/phil 28> ls -dl /tmp/p
-rw----rw- 1 root root 25 Aug 13 22:49 /tmp/p
lt1a/phil/3 /home/phil 29> cat /tmp/p
cat: /tmp/p: Permission denied
lt1a/phil/3 /home/phil 30>

/tmp/p is (appears to be) a directory, to the “execute”bit must be set for it to be read…try

Code:

chmod 707

GazL · 08-14-2022, 02:13 PM

Don't think so. The first character of the ls -l output would be 'd' if it were a directory. Also, the link count would be higher than 1.

scasey · 08-14-2022, 02:34 PM

Quote:

Originally Posted by GazL

Don't think so. The first character of the ls -l output would be 'd' if it were a directory. Also, the link count would be higher than 1.

Good point…my bad. Never mind

!!! · 08-14-2022, 04:49 PM

Worked for me meaning I could not reproduce it.

A wild guess: #3: phil is member of 0(root) group.

please post the output of:

id
IF not in 0(root) group, then:
head -1 /etc/group
And then look for: ?'fs weirdness'?:
ls -ld /tmp; df /tmp; grep /tmp /proc/mounts

And if still not, ?#1: what distro???
(custom Solaris From Scratch?

)

Apparently the ugo hierarchy is followed.

I couldn't come up with the right Web Search keywords to get a good article that explains this. I tried:
unix|linux follow first match permission order hierarchy

Skaperen · 08-14-2022, 07:19 PM

yes, user phil is in root group. so i guess that causes it to check the group permission. will need to check why my upgrade to Xubuntu 20.04 put some users in group root. i've been using -rw----rw- on these files (single letter in /tmp, owned by root, intended to allow every user to read or write without being able to change permissions). yeah, i could change to -rw-rw-rw- but i've had -rw----rw- on these for ages. i do this because i switch between users very often but copy & paste doesn't go between users (separate X servers).

rkelsen · 08-14-2022, 07:57 PM

Quote:

Originally Posted by Skaperen

yes, user phil is in root group. so i guess that causes it to check the group permission.

Yeah, that sounds right.