12-08-2003
Same problem, kinda
I have this same problem except when I create the semaphore file using a shell script, what happens if the shell script fails and the semaphore file is sitting out there forever?
So, the next time the script runs, it sees the semaphore file and doesn't run.
I need something like a 'finally' block in Java where if the shell script bails out, it needs to remove the semaphore file.
Any idea how to do this using shell scripting?
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi,
I want to do the foll steps:
1. Check if someone has a lock on my file1.
2. if file1 is locked by any other user
wait in a loop till another user releases lock
3. when lock released, lock file1.
4. do procesing (write) on file1.
5. processing complete. release lock on file1.
... (2 Replies)
Discussion started by: sunil_neha
2 Replies
2. Shell Programming and Scripting
hi Guys,
I just wondering how I can check and ensure a file is not locked by another process. I need to modify a file using sed but I need to ensure that is not being modified by another process at the same time. Thanks.
Harby. (2 Replies)
Discussion started by: hariza
2 Replies
3. Shell Programming and Scripting
I have a file named "suspected" with series of line like these :
{'protocol': 17, 'service': 'BitTorrent KRPC', 'server': '219.78.120.166', 'client_port': 52044, 'client': '10.64.68.44', 'server_port': 8291, 'time': 1226506312L, 'serverhostname': ''}
{'protocol': 17, 'service': 'BitTorrent... (3 Replies)
Discussion started by: rk4k
3 Replies
4. UNIX for Advanced & Expert Users
Hi,
I want to list out all files which are lock by some process.
ex- ~/critical
I want to list all files in critical directory which has been locked.
I need this very badly. Any suggestion highly appriciated.
Regards,
Ashok (1 Reply)
Discussion started by: ashokd001
1 Replies
5. UNIX for Dummies Questions & Answers
using OS X and the Terminal, I'd like to find all locked files in a specified directory, unlock them, and print a list of those files that were unlocked
how can I do this?
I'm familiar with chflags nouchg for unlocking one file but not familiar with unix enough to do what I'd like.
Thanks! (0 Replies)
Discussion started by: alternapop
0 Replies
6. Solaris
Hi Guys.
This is part of my filesystem structure :
Filesystem size used avail capacity Mounted on
/dev/md/dsk/d0 47G 5.2G 42G 12% /
/devices 0K 0K 0K 0% /devices
ctfs 0K 0K 0K 0% ... (2 Replies)
Discussion started by: aggadtech08
2 Replies
7. Shell Programming and Scripting
Dear community,
I've a continuos tcpdump on redhat that close the dumped file every 100000 captured packets.
To avoid disk full I would like to gzip the closed *.cap file. But how can I check if the file is currently opened by tcpdump and skip it from gzip?
Thanks!
EDIT: Just to post an... (9 Replies)
Discussion started by: Lord Spectre
9 Replies
8. UNIX for Dummies Questions & Answers
I am facing an Issue with a particular Unix Account ( ie a particular Userid) getting LOCKED everyday between 7:30am and 8:00am. The Password associated with this particular Account has been setup such that it should never Expire at all but it does LOCK the Account after more than 3 failed... (5 Replies)
Discussion started by: pchegoor
5 Replies
9. Shell Programming and Scripting
I was trying to read the file to create a table in SAS and I got error as follows while I read.
Resource is write-locked by another user. File
=/usr/sas/sas_config/Lev1/SASApp/StoredProcessServer/Logs/SASApp_STPServer_2015-09-29_tmp_18208.log. System Error Code =
0.
ERROR: File is in... (10 Replies)
Discussion started by: Ram Kumar_BE
10 Replies
10. Shell Programming and Scripting
Hi Experts,
I am beginner to shell scripting, I have a archive script which will connect to the FTP server and archive the files from FTP source location to FTP archive location.
Now the problem here is, the script working for few files and not working for few.I am facing the below error... (1 Reply)
Discussion started by: spidy
1 Replies
LEARN ABOUT HPUX
sem_post
sem_post(2) System Calls Manual sem_post(2)
NAME
sem_post - unlock a POSIX semaphore
SYNOPSIS
DESCRIPTION
is used to post the semaphore referenced by sem. The calling thread will not return from its call to unless it can either: increment the
semaphore value, if there are no blocked threads on this semaphore; give the semaphore to a blocked thread, if there are any blocked
threads on this semaphore; or have an error condition.
If the semaphore value is < 0, the semaphore has blocked threads, waiting for it to become available (the absolute value of the semaphore's
value indicates the number of waiters at that moment). If the semaphore value is >= 0, the semaphore has no waiters.
If the semaphore has no waiters at the time its value is checked, the semaphore's value will be atomically incremented, with respect to the
checking of its value, up to its maximum value as specified by If the semaphore has waiters at the time its value is checked, the semaphore
value is not changed. Instead, the calling thread will attempt to wake up a waiter. If the semaphore has waiters having realtime priori-
ties, the thread must wake up the highest priority waiter. Otherwise the thread at the head of the channel queue is woken up.
When a waiter is successfully woken, the semaphore being posted will be given to the woken waiter. In other words, the state of the sema-
phore remains unchanged. Instead, the semaphore being posted will be inherited by the waiter being woken from this call to
If the specified semaphore referred to by sem is a named semaphore, then this semaphore must have been opened by the calling process with
The calling process must have both read and write permissions on the semaphore to perform this operation. The routine may be called asyn-
chronously, i.e. from a signal handler.
To use this function, link in the realtime library by specifying on the compiler or linker command line.
EXAMPLES
The following call to will post the semaphore sem.
RETURN VALUE
A successful call to will return 0 and the calling thread would have posted the semaphore. Otherwise, the call to will return -1 with
errno set to the appropriate value of the error condition.
ERRORS
fails and does not perform the requested operation if any of the following conditions are encountered:
[EPERM] The calling process does not have the privileges necessary to post the semaphore.
[EINVAL] The argument sem does not refer to a valid semaphore.
SEE ALSO
<semaphore.h>.
STANDARDS CONFORMANCE
sem_post(2)