LinuxQuestions.org
Share your knowledge at the LQ Wiki.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software
User Name
Password
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.

Notices


Reply
  Search this Thread
Old 06-10-2004, 11:44 PM   #1
Soujiro
LQ Newbie
 
Registered: Apr 2004
Posts: 14

Rep: Reputation: 0
Problem with SCREEN


I have a dedicated server on the east coast, and i connect to it via SSH. I run game servers on it.

I cant run this program on screen, my screen works with my game servers, but i have this program called HLTV. When i start hltv with ./hltv, it works perfect. But i cant use screen with it.

I went into the proper directory and I typed:

Screen -A -m -d -S ./hltv

I did this with a NON root user on SSH and it said:

Must run suid root for multiuser support.

So i figured u cant do it on a nonuser, so i went into ROOT and did the same thing, and i got THIS msg:

Cannot identify account '.'.



I dont know what is wrong, plz help.

Thanks,
Chris
 
Old 06-11-2004, 02:13 AM   #2
motub
Senior Member
 
Registered: Sep 2003
Location: The Netherlands
Distribution: Gentoo (main); SuSE 9.3 (fallback)
Posts: 1,607

Rep: Reputation: 46
Quote:
Must run suid root for multiuser support.
OK, as a non-root user, you get a message to do something, as root you get a message that the command is malformed.

I would suggest you take the first option and set the sticky bit on whatever needs it (not sure if the message refers to screen or hltv, or even ssh itself).

The first error is telling you that there is a permissions error, but it can be fixed.

Quote:
In addition to the basic file access modes (read, write, and execute), there are also a few special purpose modes. The special mode discussed in this week's tip is SUID, or set user ID.

If a file (command) is an executable and has the SUID bit set, the process running the command inherits the privileges and access rights of the file's owner for its duration, not those of the user who created the process. A frequently used UNIX command that exhibits this configuration is the passwd command:

-r-sr-sr-x 3 root sys 73748 Nov 2 2001 /usr/bin/passwd

The "s" in the third position of the owner permission set indicates set user ID and execute permission. Non-privileged users running passwd need this level of access (root) because the access-restricted /etc/shadow file has to be updated each time a login password is changed. Notice the ownership and permissions for this file:

-r-------- 1 root sys 346 Aug 16 15:14 /etc/shadow

If passwd was ran without having root's access rights, a non-privileged user would be unable to update /etc/shadow.

Just like basic file access modes, the SUID bit is also set with the chmod command. Consider the starting access mode of unixprogram:

-r-xr-xr-x 1 root other 647 Sep 6 16:17 unixprogram

The following command will set the SUID bit for this file:

# chmod 4555 unixprogram
# ls -l unixprogram
-r-sr-xr-x 1 root other 647 Sep 6 16:17 unixprogram

As you can see, the "x" in the owner permission set was changed to "s". Review chmod's man page for more information regarding the setting of this special permission.

It is important to recognize that using this functionality may also introduce security vulnerabilities, especially if used with files owned by root. This becomes even more of a concern if the files are shell scripts because of the relative ease in which they can be exploited.
(from Special Purpose Access Modes (Permissions) - Part I - SUID (set user ID).)

The SUID bit is also called the "sticky bit" (as the bit "sticks" to the file, no matter how conditions the file is being used under may change).

So if you set the sticky bit on the program that's asking for it to be set, you should be able to run that command as a non-root user.

Hope this helps.

Last edited by motub; 06-11-2004 at 02:15 AM.
 
Old 06-11-2004, 01:09 PM   #3
Soujiro
LQ Newbie
 
Registered: Apr 2004
Posts: 14

Original Poster
Rep: Reputation: 0
Wait i solved it, i forgot to add a name for the -S command :P

screen -A -m -d - S hltv ./hltv

Thanks anyway for the huge msg motub.
 
Old 08-28-2013, 04:39 AM   #4
2fishandchips
LQ Newbie
 
Registered: Aug 2013
Posts: 1

Rep: Reputation: Disabled
Problem with screen

Had the same problem using screen with option -dm only
This worked for me.
screen -dm bash -c "./temp.sh"
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Screen problem jocast Linux - Hardware 0 11-14-2005 04:06 PM
my screen have a problem rammstein_68 Linux - General 8 02-14-2005 12:54 PM
See through Screen Problem! techrolla Linux - General 8 01-02-2004 10:01 PM
Screen Problem tntcoder Linux - Laptop and Netbook 6 09-17-2003 12:39 PM
Screen Problem please help? Remark Linux - Software 3 06-17-2002 02:53 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Software

All times are GMT -5. The time now is 06:06 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration