04-11-2007
Quote:
Originally Posted by naren_chella
so i have to locak it before i update it .
any information reg the same a C program to lock , remove and unlock the at.allow so that we can avoid concurrency issues .
Look at
https://www.unix.com/showthread.php?t...highlight=lock
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Anyone have a simple shell script that will prompt and accept screen input for each field that is required in the /etc/passwd file? (3 Replies)
Discussion started by: Relykk
3 Replies
2. Shell Programming and Scripting
Hi,
I need to convert user-input from '(this)' to '\(this\)' before passing it to egrep. I've tried using TR, SED and NAWK to add the backslash, but the most I ever get is a backslash without a '(' or ')'.
Any ideas?
Thanks! (13 Replies)
Discussion started by: netguy
13 Replies
3. UNIX for Dummies Questions & Answers
I'm using SAM to add users on an HP and they're adding fine. But in /etc/group it only lists the group names. It's not adding the users in there. Is there a way to have them put in there without going into SAM and modifying the group and adding them? I guess what I want to happen is when I add... (1 Reply)
Discussion started by: golfhakker
1 Replies
4. Shell Programming and Scripting
I'm trying to create a script to remove users from sudoers on multiple servers. I'm able to do this with a one-line script using sed, but only if it's on one server.
Example: sed '/someuser/d' /host/local/etc/sudoers
Also, I think the problem with this one-line script is that I would have to... (4 Replies)
Discussion started by: em23
4 Replies
5. UNIX for Dummies Questions & Answers
Hello everyone and let me start off by thanking anyone who can help with this.
I work for a company that uses Unix as one of their servers. I'm not at all familar with Unix beyond logging after I restart the server:rolleyes: I'm looking for some command that will bring me up a list of current... (3 Replies)
Discussion started by: disgracedsaint
3 Replies
6. UNIX for Dummies Questions & Answers
Hello there,
I want to add new users to my system, so, being logged in as root I do useradd -m user_name, and the new user is added to the system. The problem is that it has more privileges than I expected. If I do su user_name then I am allowed to do cat /etc/passwd , so it is... (4 Replies)
Discussion started by: help.goes.here
4 Replies
7. Solaris
How do I remove a user from a group? I'm using the usermod command but its not working.
I have a user "abc" who is a member of the groups root and other. I'm trying to remove him from the group "other" (using CLI) which is his secondary group but it's not working.
How do I do this? Is there any... (11 Replies)
Discussion started by: the_red_dove
11 Replies
8. AIX
I apologize if this is a simple/stupid question. When I add users in smit as root, many(most) of the fields are automatically popluated with some basic default values.
Some other admins here have access to create users via sudo, however when they create users (sudo smit users), the user gets... (3 Replies)
Discussion started by: mshilling
3 Replies
9. Shell Programming and Scripting
Hi guys,
I've a simple linux script (made by my friend), which adds users to the system from userlist file. it also creates user home dir and copies certain files to the directory. To be honest, am a newbie in scripting so am unable to fully understand how the script is working. unfortunately,... (30 Replies)
Discussion started by: vish6251
30 Replies
10. Shell Programming and Scripting
hello i'm making a bash script for adding users from a txt fille
i have a basic script that adds users and their password . when you type the users by hand , now i want to upgrade my script with a txt file of users and their password , but i don't know how to start .
my txt file looks... (10 Replies)
Discussion started by: Roggy
10 Replies
LEARN ABOUT LINUX
lockfile-touch
lockfile-progs(1) Lockfile programs lockfile-progs(1)
NAME
lockfile-progs - command-line programs to safely lock and unlock files and mailboxes (via liblockfile).
SYNOPSIS
mail-lock [--use-pid] [--retry retry-count]
mail-unlock
mail-touchlock [--oneshot]
lockfile-create [--use-pid] [--retry retry-count] [--lock-name] filename
lockfile-remove [--lock-name] filename
lockfile-touch [--oneshot] [--lock-name] filename
lockfile-check [--use-pid] [--lock-name] filename
DESCRIPTION
Lockfile-progs provides a set a programs that can be used to lock and unlock mailboxes and files safely (via liblockfile):
mail-lock - lock the current user's mailbox
mail-unlock - unlock the current user's mailbox
mail-touchlock - touch the lock on the current user's mailbox
lockfile-create - lock a given file
lockfile-remove - remove the lock on a given file
lockfile-touch - touch the lock on a given file
lockfile-check - check the lock on a given file
By default, the filename argument refers to the name of the file to be locked, and the name of the lockfile will be filename .lock. How-
ever, if the --lock-name argument is specified, then filename will be taken as the name of the lockfile itself.
Each of the mail locking commands attempts to lock /var/spool/mail/<user>, where <user> is the name associated with the effective user ID,
as determined by via geteuid(2).
Once a file is locked, the lock must be touched at least once every five minutes or the lock will be considered stale, and subsequent lock
attempts will succeed. Also see the --use-pid option and the lockfile_create(3) manpage.
The lockfile-check command tests whether or not a valid lock already exists.
OPTIONS
-q, --quiet
Suppress any output. Success or failure will only be indicated by the exit status.
-v, --verbose
Enable diagnostic output.
-l, --lock-name
Do not append .lock to the filename. This option applies to lockfile-create, lockfile-remove, lockfile-touch, or lockfile-check.
-p, --use-pid
Write the current process id (PID) to the lockfile whenever a lockfile is created, and use that pid when checking a lock's validity.
See the lockfile_create(3) manpage for more information. This option applies to lockfile-create, lockfile-remove, lockfile-touch, and
lockfile-check.
-o, --oneshot
Touch the lock and exit immediately. This option applies to lockfile-touch and mail-touchlock. When not provided, these commands will
run forever, touching the lock once every minute until killed.
-r retry-count, --retry retry-count
Try to lock filename retry-count times before giving up. Each attempt will be delayed a bit longer than the last (in 5 second incre-
ments) until reaching a maximum delay of one minute between retries. If retry-count is unspecified, the default is 9 which will give
up after 180 seconds (3 minutes) if all 9 lock attempts fail.
EXAMPLES
Locking a file during a lengthy process:
lockfile-create /some/file
lockfile-touch /some/file &
# Save the PID of the lockfile-touch process
BADGER="$!"
do-something-important-with /some/file
kill "${BADGER}"
lockfile-remove /some/file
EXIT STATUS
0
For lockfile-check this indicates that a valid lock exists, otherwise it just indicates successful program execution.
Not 0
For lockfile-check a non-zero exit status indicates that the specified lock does not exist or is not valid. For other programs it
indicates that some problem was encountered.
SEE ALSO
maillock(3)
touchlock(3)
mailunlock(3)
lockfile_create(3)
lockfile_remove(3)
lockfile_touch(3)
lockfile_check(3)
AUTHOR
Written by Rob Browning <rlb@defaultvalue.org>
0.1.12 2008-02-10 lockfile-progs(1)