I need to pass a parameter that will then be grepped.
I need it to grep /paramater and then have a space
so if 123 was passed my grep would be grep '/123 ' sample.log
this works fine from the command line
but when i try and set it searchThis="/$2 "
and then run grep $searchThis... (6 Replies)
Hello,
I would like for the user to input the date for a particular log file, then have the input sent to a variable, which is then used via grep to extra the logs for the specific date the user request.
I did some searching, but I still don't understand why I'm not seeing any result.
... (4 Replies)
Hi
I am having hard time getting this right and need some help. I Have several log files, and everyone contains the following 3 lines at the end:
4 ETW000 Disconnected from database.
4 ETW000 End of Transport (0000).
4 ETW000 date&time: 13.01.2011 - 08:03:28
I need to capture the value... (7 Replies)
I have a list of fields that I want to check a file for, returning that field if it not found at all in the file. Is there a way to do a grep -lc and return the passed variable too rather then just the count?
I am doing some crappy work-around now but I was not sure how to regrep this for :0 so... (3 Replies)
Hi All,
I have a text file which looks like this:
computer programming
systems engineering
I want to get rid of these square brackets and also the text that is inside these brackets. So that my final text file looks like this:
computer programming
systems engineering
I am using... (3 Replies)
Hello Team,
I have a script which will grep for a time from a file. I have following code to grep for a time in a file.
node=`hostname`
current_date=`date`
file11=weblogic.log
next_date=`date '+%b %e, %Y'`
next_date_time11=`grep -i "${#next_date}" ${file11}| tail -1 | awk... (3 Replies)
Hi Guys,
I want to set a variable which happend to have square brackets in them. I tried multiple ways that is by escaping it with quotes (both single and double ) but it didn't help.
All I want is:
set x = slicearray.slice\.post
My failed attempts were:
set x = "slicearray.slice\.post"... (3 Replies)
Hi All,
When i am logged into a server , i am able to assign grep value to a variable as follows.
VAR=`grep 'Listener stopped' /logs/perf.log`
However, when i log out of the server, and try to execute the following command by first SSHing into server, it throws error.
$ VAR=`ssh Server... (4 Replies)
I have a lot of files with keywords and unique names. I'm using a shell script to refer to a simple pattern file with comma separated values in order to match on certain keywords. The problem is that I don't understand how to handle the wildcard values when I want to skip over the unique names.
... (5 Replies)
Im trying to search for a single variable in the first field and from that output use awk to extract out the lines that contain a value less than a value stored in another variable. Both the variables are associated with each other.
Any guidance is appreciated.
File that contains the... (6 Replies)
Discussion started by: ncwxpanther
6 Replies
LEARN ABOUT CENTOS
flock
FLOCK(1) User Commands FLOCK(1)NAME
flock - manage locks from shell scripts
SYNOPSIS
flock [options] <file|directory> <command> [command args]
flock [options] <file|directory> -c <command>
flock [options] <file descriptor number>
DESCRIPTION
This utility manages flock(2) locks from within shell scripts or the command line.
The first and second forms wrap 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. By default, if the lock cannot be
immediately acquired, flock waits until the lock is available.
The third form uses open file by file descriptor number. See examples how that can be used.
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 rather than wait if the lock cannot be immediately acquired. See the -E option for the exit code used.
-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.
-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.
-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.
-c, --command command
Pass a single command, without arguments, to the shell with -c.
-h, --help
Print a help message.
-V, --version
Show version number 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 else but an options -n or -w failures which return either the value given by the
-E option, or 1 by default.
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 <ftp://ftp.kernel.org/pub/linux/utils/util-
linux/>.
util-linux September 2011 FLOCK(1)