make sense and corrected the script(though earlier it was running fine (), don't know how).
Currently I'm trying to get the command I'm running using below sample test script:
Output:
Still I'm not getting the command, so that I can awk'ed the passed argument and put into a file. So the logic will be:
Once I'll restart script:
if this new file exist
take this new file
else
use old config file
once successfully done, I'll remove the error file (if any). Please suggest if this feasible.
Hi All,
I am working on solaris 8 sparc machine with 2 cpu.
I am trying to run my application which generates files. I run multiple instance of the application, but the results don't seem to show as if it were runing parallely.
When i run the application once it takes 12 secs to generate a... (1 Reply)
Hi
I want to run two shell script files parallely. These two scripts are interacting with the database. can any body help on this Pls
Regards
Audippa naidu.M (3 Replies)
Hi
I am looking for some kind of feature in unix that will help me write a script that can invoke multiple processes in parallel. And make sure that the multiple parallel processes complete successfully before I proceed to the next step.
Someone suggested something called timespid or... (6 Replies)
hi i am preparing a set of batches for a set of files sequentially
There is a folder /xyz where all the files reside
now all the files starting with
01 - will be appended for one below other to form a batch batch01
then all the files starting with
02 - will be appended for one below other to... (7 Replies)
Hello everybody,
I have a little problem with one of my program. I made a plugin for collectd (a stats collector for my servers) but I have a problem to make it run in parallel.
My program gathers stats from logs, so it needs to run in background waiting for any new lines added in the log... (0 Replies)
Hello
I have a shell script with multiple sections in it. Like, verify pre-requisites, ch co version, stop services , install product , post migration steps, start services, send status email.
If the script fails at certain step, (like after product installation) it can't be re-run since the... (2 Replies)
I have 10,000 + files, each of which I need to zip using bzip2.
Is ti possible to use bash to create 8 parallel streams sending a new file to be processed from the list when one of the others has finished? (1 Reply)
Discussion started by: garethsays
1 Replies
LEARN ABOUT MOJAVE
shlock
SHLOCK(1) BSD General Commands Manual SHLOCK(1)NAME
shlock -- create or verify a lock file for shell scripts
SYNOPSIS
shlock [-du] [-p PID] -f lockfile
DESCRIPTION
The shlock command can create or verify a lock file on behalf of a shell or other script program. When it attempts to create a lock file, if
one already exists, shlock verifies that it is or is not valid. If valid, shlock will exit with a non-zero exit code. If invalid, shlock
will remove the lock file, and create a new one.
shlock uses the link(2) system call to make the final target lock file, which is an atomic operation (i.e. "dot locking", so named for this
mechanism's original use for locking system mailboxes). It puts the process ID ("PID") from the command line into the requested lock file.
shlock verifies that an extant lock file is still valid by using kill(2) with a zero signal to check for the existence of the process that
holds the lock.
The -d option causes shlock to be verbose about what it is doing.
The -f argument with lockfile is always required.
The -p option with PID is given when the program is to create a lock file; when absent, shlock will simply check for the validity of the lock
file.
The -u option causes shlock to read and write the PID as a binary pid_t, instead of as ASCII, to be compatible with the locks created by
UUCP.
EXIT STATUS
A zero exit code indicates a valid lock file.
EXAMPLES
BOURNE SHELL
#!/bin/sh
lckfile=/tmp/foo.lock
if shlock -f ${lckfile} -p $$
then
# do what required the lock
rm ${lckfile}
else
echo Lock ${lckfile} already held by `cat ${lckfile}`
fi
C SHELL
#!/bin/csh -f
set lckfile=/tmp/foo.lock
shlock -f ${lckfile} -p $$
if ($status == 0) then
# do what required the lock
rm ${lckfile}
else
echo Lock ${lckfile} already held by `cat ${lckfile}`
endif
The examples assume that the file system where the lock file is to be created is writable by the user, and has space available.
HISTORY
shlock was written for the first Network News Transfer Protocol (NNTP) software distribution, released in March 1986. The algorithm was sug-
gested by Peter Honeyman, from work he did on HoneyDanBer UUCP.
AUTHORS
Erik E. Fair <fair@clock.org>
BUGS
Does not work on NFS or other network file system on different systems because the disparate systems have disjoint PID spaces.
Cannot handle the case where a lock file was not deleted, the process that created it has exited, and the system has created a new process
with the same PID as in the dead lock file. The lock file will appear to be valid even though the process is unrelated to the one that cre-
ated the lock in the first place. Always remove your lock files after you're done.
BSD June 29, 1997 BSD