You can save the last timestamp processed by your awk script and reload that value in your shell script before calling awk the next time and then have awk skip over all lines with a timestamp that is less than or equal to the saved timestamp. For example:
Obviously, you should also verify that the read was successful, but this might work as a starting point for what you need.
This User Gave Thanks to Don Cragun For This Post:
Anyone know of a guide or instructions for Solaris
I got to configure a SBUS HBA to talk to a tape robot.
I have done this on a switch but not point to point.
just going HBA >>>>> TAPE Fibre simple two nodes
Kie (6 Replies)
Hi the following c-code utilizing the 'read()' man 2 read method cant read in files larger that 2gig.
Hi I've found a strange problem on ubuntu64bit, that limits the data you are allowed to allocate on a 64bit platform using the c function 'read()'
The following program wont allow to allocate... (14 Replies)
Hi Guys,
Happy New Year to you all!
I have a requirement to read an embedded new-line using KSH's read builtin.
Here is what I am trying to do:
run_sql "select guestid, address, email from guest" | while read id addr email
do
## Biz logic goes here
done
I can take care of any... (6 Replies)
Hello All,
i am a newbie and need some help when reading a csv file in a bourne shell script. I want to read 10 lines, then wait for a minute and then do a reading of another 10 lines and so on in the same way. I want to do this till the end of file.
Any inputs are appreciated
... (3 Replies)
Hi
I am new to writing script and want to use a Bash Piped while-read and read from user input.
if something happens on server.log then do while loop or if something happend on user input then do while loop.
Pseudocode something like:
tail -n 3 -f server.log | while read serverline || read... (8 Replies)
hi,
I would like to ask or is it possible to dump a hex using dd from starting point to end point just like the "xxd -s 512 -l 512 <bin file>"
I know the redirect hexdump -C but i can't figure it out the combination options of dd.
Hope someone can share their knowledge..
Thanks in... (3 Replies)
For my backup , I mount and external hard disk to /mnt/mybackup and then I do an rsync to /mnt/mybackup
If for some reason the rsync fails, I want to prevent it from writing data on the server hard disk itself since the external hard disk will no longer be mounted on it.
I want /mnt/mybackup... (8 Replies)
Hi.
How can I create a history function? (By "read" command or so)
&
How can I configure a read command so that the arrow keys are not displayed so funny? (^[[A)
Thanks in advance. (4 Replies)
Hi again,
first thanks for all your suggestions. This forum it is very useful.
I have a question. Is it possible to read from the last line a file was closed. For example, imagine that i've got a file with a LOT of timestamps :
1467387616.868717770
1467387616.874189609... (1 Reply)
How to create a new mount point with 600GB and add 350 GBexisting mount point
Best if there step that i can follow or execute before i mount or add diskspace IN AIX
Thanks (2 Replies)
Discussion started by: Thilagarajan
2 Replies
LEARN ABOUT SUSE
flock
FLOCK(1) H. Peter Anvin FLOCK(1)NAME
flock - Manage locks from shell scripts
SYNOPSIS
flock [-sxon] [-w timeout] lockfile [-c] command...
flock [-sxon] [-w timeout] lockdir [-c] command...
flock [-sxun] [-w timeout] fd
DESCRIPTION
This utility manages flock(2) locks from within shell scripts or the command line.
The first and second forms wraps the lock around the executing a command, in a manner similar to su(1) or newgrp(1). It locks a specified
file or directory, which is created (assuming appropriate permissions), if it does not already exist.
The third form is convenient inside shell scripts, and is usually used the following manner:
(
flock -s 200
# ... commands executed under lock ...
) 200>/var/lock/mylockfile
The mode used to open the file doesn't matter to flock; using > or >> allows the lockfile to be created if it does not already exist, how-
ever, write permission is required; using < requires that the file already exists but only read permission is required.
By default, if the lock cannot be immediately acquired, flock waits until the lock is available.
OPTIONS -s, --shared
Obtain a shared lock, sometimes called a read lock.
-x, -e, --exclusive
Obtain an exclusive lock, sometimes called a write lock. This is the default.
-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.
-n, --nb, --nonblock
Fail (with an exit code of 1) rather than wait if the lock cannot be immediately acquired.
-w, --wait, --timeout seconds
Fail (with an exit code of 1) if the lock cannot be acquired within seconds seconds. Decimal fractional values are allowed.
-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 hold ing the lock.
-c, --command command
Pass a single command to the shell with -c.
-h, --help
Print a help message.
AUTHOR
Written by 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-ng package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.
flock utility 4 Feb 2006 FLOCK(1)