That is quite an expensive way to do it since it causes sed to read the entire file twice per iteration. You can instead obtain the $now from the file size, and use tail -c to jump to that offset:
Code:
start=$(<wherewasi)
now=$(ls -l moxy.log | awk '{print $5}')
if [[ $now -lt $start ]] ; then
start=0
fi
echo $now > wherewasi
tail -c +$(($start + 1)) moxy.log | grep 'stuff i want to find'
Hello:
I'm a very newbee at UNIX/AIX.
What i want to do is to tail a file from the bottom until a certain string is found and write all the lines after the found string to another file.
I've tried out a lot of combination with tail and grep but doesn't find the good one.
Could someone help... (4 Replies)
Hello all,
I have some weird problem that kinda baffles me. Say I have the following test file:
claudia:~/tmp$ cat testfile.txt
This is a test line
This is the second test line
And yeah, this is the third test line
Then say I want to tail the file, grep for the word "third" then... (7 Replies)
The program that is running on my machine generates log files. I want to be able to know the number of lines that contain "FT" in the most recent log file. I wrote the following, but it always returns zero. And I know the count is not zero. Any ideas?
ls -rt *.log | tail -n 1 | grep -c FT (6 Replies)
I need to tail -f a file so I can monitor it as it is being written to. However, there is a lot of garbage in the file that I don't care about. So normally I would just pipe and grep for the string that is important to me. However, in this case, there are two things I need to grep for. I can't... (3 Replies)
I have a basic tail/grep question. I have logs that are generated & kept in a directory called alert_audit. I am using "tail" to see the logs that are coming in, but I only need logs that contain the IP address 10.249.185. or 10.247.231.
Here is the command I have, but it pulls all IP... (3 Replies)
This isn't exactly a question. Just thought I'd share something I just wrote and found useful.
For those of you on modern linux boxen: you may be aware that there's a lovely little tool called notify-send that you can use to send notifications to the desktop. Any experienced shell-scripter could... (0 Replies)
Hello,
How to tail -f multi logfile from multi path in 1 shell script.
File & Path
/usr/home/localmode/mode110l/log/logic/number110/digit110_digit110m4_2013050210.txt
/usr/home/localmode/mode103l/log/logic/number103/digit103_digit103m4_2013050210.txt... (4 Replies)
hi guys,
I perform a sort of monitoring. I have a server running and with
tail -f | grep "Searchstring"I monitor the log-file for recent specific entries. This is ok and works fine.
Now, in addition I want to have my search results not posted into the shell but into a file. I tried:
tail... (3 Replies)
Good Morning,
i ran into some trouble this morning while 'improving' my monitoring stuff. i would like to get a warning when the number of mails sent (outbound) by postfix is above a certain number. so far, so easy. to test that i simply put
cat /var/log/mail.info | grep 'to=<' | grep -v -e... (1 Reply)
Hello,
I would like to write script to tail a file for different environment
But the number of lines are keep changing
How can I write a script
For example:
env could : A, B or C
and log files could be a.log, b.log and c.log
with the number of lines can change
say sometimes it 100 last... (9 Replies)
Discussion started by: encrypt_decrypt
9 Replies
LEARN ABOUT SUSE
tail
TAIL(1) User Commands TAIL(1)NAME
tail - output the last part of files
SYNOPSIS
tail [OPTION]... [FILE]...
DESCRIPTION
Print the last 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With
no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options too.
-c, --bytes=N
output the last N bytes; alternatively, use +N to output bytes starting with the Nth of each file
-f, --follow[={name|descriptor}]
output appended data as the file grows; -f, --follow, and --follow=descriptor are equivalent
-F same as --follow=name --retry
-n, --lines=N
output the last N lines, instead of the last 10; or use +N to output lines starting with the Nth
--max-unchanged-stats=N
with --follow=name, reopen a FILE which has not changed size after N (default 5) iterations to see if it has been unlinked or
renamed (this is the usual case of rotated log files)
--pid=PID
with -f, terminate after process ID, PID dies
-q, --quiet, --silent
never output headers giving file names
--retry
keep trying to open a file even when it is or becomes inaccessible; useful when following by name, i.e., with --follow=name
-s, --sleep-interval=S
with -f, sleep for approximately S seconds (default 1.0) between iterations
-v, --verbose
always output headers giving file names
--help display this help and exit
--version
output version information and exit
If the first character of N (the number of bytes or lines) is a `+', print beginning with the Nth item from the start of each file, other-
wise, print the last N items in the file. N may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB
1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y.
With --follow (-f), tail defaults to following the file descriptor, which means that even if a tail'ed file is renamed, tail will continue
to track its end. This default behavior is not desirable when you really want to track the actual name of the file, not the file descrip-
tor (e.g., log rotation). Use --follow=name in that case. That causes tail to track the named file by reopening it periodically to see if
it has been removed and recreated by some other program.
AUTHOR
Written by Paul Rubin, David MacKenzie, Ian Lance Taylor, and Jim Meyering.
REPORTING BUGS
Report tail bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
COPYRIGHT
Copyright (C) 2009 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
The full documentation for tail is maintained as a Texinfo manual. If the info and tail programs are properly installed at your site, the
command
info coreutils 'tail invocation'
should give you access to the complete manual.
GNU coreutils 7.1 July 2010 TAIL(1)