Something like this longhand:-
OSX 10.7.5, deafult bash terminal.
Results:-
EDIT:
The line "exit 1" is deliberately added but can be removed if not needed.
This section does not change or reset the number of retries but that is an easy task to cure...
Last edited by wisecracker; 06-22-2014 at 03:18 PM..
Reason: See above...
This User Gave Thanks to wisecracker For This Post:
I want to create an automated script which is called by another maually executed script.
The condition is that the no one should be able to manually execute the automated script.
The automated script can be on the same machine or it can be on a remote machine.
Can any one suggest a check in the... (1 Reply)
Hi ,
I have a date parameter passed in YYYYMMDD format , how can I check whether it is Sat or Sun on Solaris box , as we can do the same easily on linux box by using date -d YYYYMMDD '+a' .
Any pointres will be really helpful . (5 Replies)
Hi,
i have a script 'a.sh' that should be called only by certain scripts like b.sh, c.sh
Inside a.sh, how can i determine
1) if this script was run directly from command prompt (or scheduler)
2) if called via other scripts?
Is there an easy way to get parent process name (not just pid),... (2 Replies)
Hello,
I wanted to run one of my shell script for every sunday at 5PM.
Here is the crontab entry i am using..
00 17 * * 0 /inventory/update.sh > /inventory/update.log 2>&1
The job is not kicking on sunday at the specified time.. Am i missing anthing?
Any help is appreciated... (2 Replies)
I have a local linux machine in which the files are dumped by a remote ubuntu server. If the process in remote server has any problem then empty files are created in local machine. Is there any way using perl script to check if the empty files are being created and delete them and then run a shell... (2 Replies)
I was to schedule a script in a crontab after every 15 days specically on every 2nd Sunday.
I know that i can schedule on basis of weekdays, but can it be done by skipping in between???:wall: (5 Replies)
Hi,
I need to create a autosys job which will run on every sunday at 7:30 AM NY time for each 10 min interval of time.
days_of_week: su
start_mins: 0,10,20,30,40,50
run_window:"07:30"
Is it fine? Please help
Thanks,
Anup (2 Replies)
Hello,
I'm looking for a bash script, that I will run from cron, that executes a php script. After 5 minutes that the php script is executed, the bash script, must check a value in a text file /public_html/check.txt
if check.txt = 0 the script will stop, if check.txt is not = 0 it must... (0 Replies)
Hi all,
I have a script that can be run via cron or via the command line.
Is there any way that I can place something on the script to be able to distinguish/differentiate whether the script was run via a user in the command line or whether it was run from the cron? (3 Replies)
Hi ALL,
I have been testing this script to run for every last Sunday of the month,looks like month which have 5 sunday (july 2016 )is not passing this and failing every time.
Here is what I am using,
current_date=31
echo " CURRENT DAY -> $current_date"
if
... (2 Replies)
Discussion started by: netdbaind
2 Replies
LEARN ABOUT XFREE86
flock
FLOCK(1) User Commands FLOCK(1)NAME
flock - manage locks from shell scripts
SYNOPSIS
flock [options] file|directory command [arguments]
flock [options] file|directory -c command
flock [options] number
DESCRIPTION
This utility manages flock(2) locks from within shell scripts or from the command line.
The first and second of the above forms wrap the lock around the execution of a command, in a manner similar to su(1) or newgrp(1). They
lock a specified file or directory, which is created (assuming appropriate permissions) if it does not already exist. By default, if the
lock cannot be immediately acquired, flock waits until the lock is available.
The third form uses an open file by its file descriptor number. See the examples below for how that can be used.
OPTIONS -c, --command command
Pass a single command, without arguments, to the shell with -c.
-E, --conflict-exit-code number
The exit code used when the -n option is in use, and the conflicting lock exists, or the -w option is in use, and the timeout is
reached. The default value is 1.
-F, --no-fork
Do not fork before executing command. Upon execution the flock process is replaced by command which continues to hold the lock.
This option is incompatible with --close as there would otherwise be nothing left to hold the lock.
-e, -x, --exclusive
Obtain an exclusive lock, sometimes called a write lock. This is the default.
-n, --nb, --nonblock
Fail rather than wait if the lock cannot be immediately acquired. See the -E option for the exit code used.
-o, --close
Close the file descriptor on which the lock is held before executing command. This is useful if command spawns a child process
which should not be holding the lock.
-s, --shared
Obtain a shared lock, sometimes called a read lock.
-u, --unlock
Drop a lock. This is usually not required, since a lock is automatically dropped when the file is closed. However, it may be
required in special cases, for example if the enclosed command group may have forked a background process which should not be hold-
ing the lock.
-w, --wait, --timeout seconds
Fail if the lock cannot be acquired within seconds. Decimal fractional values are allowed. See the -E option for the exit code
used. The zero number of seconds is interpreted as --nonblock.
--verbose
Report how long it took to acquire the lock, or why the lock could not be obtained.
-V, --version
Display version information and exit.
-h, --help
Display help text and exit.
EXAMPLES
shell1> flock /tmp -c cat
shell2> flock -w .007 /tmp -c echo; /bin/echo $?
Set exclusive lock to directory /tmp and the second command will fail.
shell1> flock -s /tmp -c cat
shell2> flock -s -w .007 /tmp -c echo; /bin/echo $?
Set shared lock to directory /tmp and the second command will not fail. Notice that attempting to get exclusive lock with second
command would fail.
shell> flock -x local-lock-file echo 'a b c'
Grab the exclusive lock "local-lock-file" before running echo with 'a b c'.
(
flock -n 9 || exit 1
# ... commands executed under lock ...
) 9>/var/lock/mylockfile
The form is convenient inside shell scripts. The mode used to open the file doesn't matter to flock; using > or >> allows the lock-
file to be created if it does not already exist, however, write permission is required. Using < requires that the file already
exists but only read permission is required.
[ "${FLOCKER}" != "$0" ] && exec env FLOCKER="$0" flock -en "$0" "$0" "$@" || :
This is useful boilerplate code for shell scripts. Put it at the top of the shell script you want to lock and it'll automatically
lock itself on the first run. If the env var $FLOCKER is not set to the shell script that is being run, then execute flock and grab
an exclusive non-blocking lock (using the script itself as the lock file) before re-execing itself with the right arguments. It
also sets the FLOCKER env var to the right value so it doesn't run again.
EXIT STATUS
The command uses sysexits.h return values for everything, except when using either of the options -n or -w which report a failure to
acquire the lock with a return value given by the -E option, or 1 by default.
When using the command variant, and executing the child worked, then the exit status is that of the child command.
AUTHOR
H. Peter Anvin <hpa@zytor.com>
COPYRIGHT
Copyright (C) 2003-2006 H. Peter Anvin.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICU-
LAR PURPOSE.
SEE ALSO flock(2)AVAILABILITY
The flock command is part of the util-linux package and is available from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils
/util-linux/>.
util-linux July 2014 FLOCK(1)