07-20-2001
From what I understand, the "sticky" bit is only allowed to be set by a superuser via the chmod command. If set the "ls" format will show a "t" in the last position of the permissions.
The sticky bits purpose is to prevent a program from swapping out of of memory when not being used. Thus, the executable image of the program (file) stays in the "swap space" even when the program is NOT being executed. In effect, it would make the program run faster (no swapping to virtual memory involved).
Since the program gets "stuck" (in the swap space) it's called "sticky mode" (controlled by the "sticky bit". Since swap space is usually at a premium (on most systems) you wouldn't want too many programs running in "sticky mode".
I'm certainly not an expert, but the above is what I gathered through reading. Hope it helps. LY18
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
I have a script that I want to be able to let user 'wcs1234' execute it, but when it runs, it will do so under the higher authority of 'cdunix'. It is my understanding that I accomplish this with a sticky bit. I have tried every variation of this but am unable to get this to work.
my script is... (2 Replies)
Discussion started by: hedrict
2 Replies
2. UNIX for Dummies Questions & Answers
What command string would you use to set the sticky bit on a directory that you own? (2 Replies)
Discussion started by: mma_buc_98
2 Replies
3. UNIX for Dummies Questions & Answers
I have the sticky bit set on my /tmp directory, but users are still able to remove files that are not owned by them. Does the /etc/group file get invloved in securing these files ?? (1 Reply)
Discussion started by: rob11g
1 Replies
4. UNIX for Dummies Questions & Answers
Hi,
could anyone please send me a link to learn/ know more about sticky bits? I am still not clear on the application of using a sticky bits.
Thanks for your help.
Regards,
UP (3 Replies)
Discussion started by: teenu18
3 Replies
5. UNIX for Dummies Questions & Answers
Hi ,
I am having file permision as
drwxrwsr_x
I kwo for deleting a file in the diretory i need w permsion as well ..
Say if i am having the permsion as
drwxrwsrwx - wil any one can delete the files in the directory ..
And one more question what is the s doing there ..... (2 Replies)
Discussion started by: arunkumar_mca
2 Replies
6. UNIX for Dummies Questions & Answers
HI
What is sticky bit?
how can be see if the sticky bit for file is set?
WHat is meaning of sticky bit set on Directory?
What is the syntax to set the sticky bit? With example
Thanks (10 Replies)
Discussion started by: skyineyes
10 Replies
7. UNIX for Advanced & Expert Users
Hi,
I understand the purpose of sticky bit on directories. But I am not very clear about what the sticky bit do on a file.
Can any one explain me in detail and with example please.
Thanks in advance. (1 Reply)
Discussion started by: praveen_b744
1 Replies
8. Shell Programming and Scripting
I want a file I create to not be deletable by other users so I created a sticky bit by chmod 1644 on the file. chown'd it to root and then tried to delete (via GUI drag to trash and empty) as a non root user and it let me. is sticky bit only good for terminal deletes or something? (4 Replies)
Discussion started by: glev2005
4 Replies
9. AIX
What is sticky bit ...and where we aill use this.. how to set this bit in files and directories (1 Reply)
Discussion started by: udtyuvaraj
1 Replies
10. AIX
as far as i understand, if sticky bit is set on a directory, the files created under tht directory cannot be deleted by ordinary user...
but we can do ths by permission itself,,, tht's assign only read permission to tht dirrectory
wht 's the difference? (1 Reply)
Discussion started by: udtyuvaraj
1 Replies
CHMOD(1) General Commands Manual CHMOD(1)
NAME
chmod - change mode
SYNOPSIS
chmod [ -Rf ] mode file ...
DESCRIPTION
The mode of each named file is changed according to mode, which may be absolute or symbolic. An absolute mode is an octal number con-
structed from the OR of the following modes:
4000 set user ID on execution
2000 set group ID on execution
1000 sticky bit, see chmod(2)
0400 read by owner
0200 write by owner
0100 execute (search in directory) by owner
0070 read, write, execute (search) by group
0007 read, write, execute (search) by others
A symbolic mode has the form:
[who] op permission [op permission] ...
The who part is a combination of the letters u (for user's permissions), g (group) and o (other). The letter a stands for all, or ugo. If
who is omitted, the default is a but the setting of the file creation mask (see umask(2)) is taken into account.
Op can be + to add permission to the file's mode, - to take away permission and = to assign permission absolutely (all other bits will be
reset).
Permission is any combination of the letters r (read), w (write), x (execute), X (set execute only if file is a directory or some other
execute bit is set), s (set owner or group id) and t (save text - sticky). Letters u, g, or o indicate that permission is to be taken from
the current mode. Omitting permission is only useful with = to take away all permissions.
When the -R option is given, chmod recursively descends its directory arguments setting the mode for each file as described above. When
symbolic links are encountered, their mode is not changed and they are not traversed.
If the -f option is given, chmod will not complain if it fails to change the mode on a file.
EXAMPLES
The first example denies write permission to others, the second makes a file executable by all if it is executable by anyone:
chmod o-w file
chmod +X file
Multiple symbolic modes separated by commas may be given. Operations are performed in the order specified. The letter s is only useful
with u or g.
Only the owner of a file (or the super-user) may change its mode.
SEE ALSO
ls(1), chmod(2), stat(2), umask(2), chown(8)
7th Edition May 22, 1986 CHMOD(1)