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 $now from the file size, and use tail -c to jump to that offset:
Hello:
I'm a very newbee at UNIX/AIX.
What i want to do is to tail a file from the bottom until a certain string is found and write all the lines after the found string to another file.
I've tried out a lot of combination with tail and grep but doesn't find the good one.
Could someone help... (4 Replies)
Hello all,
I have some weird problem that kinda baffles me. Say I have the following test file:
claudia:~/tmp$ 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 DEBIAN
plan9-tail
TAIL(1) General Commands Manual TAIL(1)NAME
tail - deliver the last part of a file
SYNOPSIS
tail [ +-number[lbc][rf] ] [ file ]
tail [ -fr ] [ -n nlines ] [ -c nbytes ] [ file ]
DESCRIPTION
Tail copies the named file to the standard output beginning at a designated place. If no file is named, the standard input is copied.
Copying begins at position +number measured from the beginning, or -number from the end of the input. Number is counted in lines, 1K
blocks or bytes, according to the appended flag or Default is -10l (ten ell).
The further flag causes tail to print lines from the end of the file in reverse order; (follow) causes tail, after printing to the end, to
keep watch and print further data as it appears.
The second syntax is that promulgated by POSIX, where the numbers rather than the options are signed.
EXAMPLES
tail file
Print the last 10 lines of a file.
tail +0f file
Print a file, and continue to watch data accumulate as it grows.
sed 10q file
Print the first 10 lines of a file.
SOURCE
/src/cmd/tail.c
BUGS
Tails relative to the end of the file are treasured up in a buffer, and thus are limited in length.
According to custom, option +number counts lines from 1, and counts blocks and bytes from 0.
Tail is ignorant of UTF.
TAIL(1)