Sponsored Content
Full Discussion: Break out of tail -f
Top Forums Shell Programming and Scripting Break out of tail -f Post 302778847 by DGPickett on Monday 11th of March 2013 04:12:53 PM
Old 03-11-2013
Well, tail -f can be a problem to manage, but the file is the file. Data can get hung up in the pipe, too. Shell can find strings without calling grep, using case. Logs can be written in blocks from a FILE* buffer. You could poll and just tail a big hunk of file. You could figure how many lines you have checked and just check up-file of there. Really economical and efficient solutions would be in C, where you can mmap() the file as it growns and monitor the content with low overhead just in areas not already checked.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

using tail -f

Working in HP-UX 10.20. I eventually want to write a bourne shell script to handle the following problem, but for now I am just toying with it at the command line. Here's what I am basically trying to do: tail -f log_X | grep n > log_Y I am doing a tail -f on log_X . Once it sees "n", I... (6 Replies)
Discussion started by: cdunavent
6 Replies

2. Shell Programming and Scripting

Tail??

Hello all, I have search the forum and could not find an answer...Here is what I am trying to do. Every 15 minutes, a script send uptime output to a logfile (dailylog.log), that file contains lines like the one below: 11:21am up 44 days, 19:15, 1 user, load average: 0.00, 0.02, 0.03 ... (7 Replies)
Discussion started by: qfwfq
7 Replies

3. Shell Programming and Scripting

tail -f

I am trying to extract a particular line from a.log which keeps appending every sec and output that into a newfile b.log which should append itself with filtered data received from a.log I tried tail -f a.log |grep fail| tee -a b.log nothing in b.log tail -f a.log |grep fail >>b.log ... (4 Replies)
Discussion started by: wannalearn
4 Replies

4. HP-UX

Break mirror so that it can be used later

Hello again, We need to install patches to HP-UX B.11.11 but would like to break the mirror it has (with out damaging it) so that in case of failure we can use this a meassure procedure. Any ideas on how to do this Thank you! (2 Replies)
Discussion started by: AQG
2 Replies

5. Shell Programming and Scripting

break out of 'if'

is it possible? because i still need to keep on reading even though i don't want to read that particular line (7 Replies)
Discussion started by: finalight
7 Replies

6. Shell Programming and Scripting

help on page break

Hi, i have a file say samp.s which has 123 a b c d 123 e f g h 123 i j k l 123 m n o p 234 a b c d 234 e f g h 234 i j k l the first 3 characters in each line are considered the key values i have one more file temp.txt which has 123 234 i want to have a page break in... (5 Replies)
Discussion started by: Sheema
5 Replies

7. Shell Programming and Scripting

break: cannot break

hi guys I am working on a menu for linux... some basic stuff. but I have an issue. I got 1 server where something is working and the same thing does not work in the same way in another linux box Basically I am simulating a command line where user insert some commands and to end and go back... (7 Replies)
Discussion started by: karlochacon
7 Replies

8. Shell Programming and Scripting

BASH: Break line, read, break again, read again...

...when the lines use both a colon and commas to separate the parts you want read as information. The first version of this script used cut and other non-Bash-builtins, frequently, which made it nice and zippy with little more than average processor load in GNOME Terminal but, predictably, slow... (2 Replies)
Discussion started by: SilversleevesX
2 Replies

9. Shell Programming and Scripting

Joining multiple files tail on tail

I have 250 files that have 16 columns each - all numbered as follows stat.1000, stat.1001, stat.1002, stat.1003....stat.1250. I would like to join all 250 of them together tail by tail as follows. For example stat.1000 a b c d e f stat.1001 g h i j k l So that my output... (2 Replies)
Discussion started by: kayak
2 Replies

10. Shell Programming and Scripting

Tail +

because the tail +2 on the first line gives me the file name pomga I do not want anything like what I miss tail +2 ejemplo.txt ouput ==> ejemplo.txt <== 1 2 3 4 5 6 7 8 9 10 (2 Replies)
Discussion started by: tricampeon81
2 Replies
TAIL(1) 								FSF								   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. --retry keep trying to open a file even if it is inaccessible when tail starts or if it becomes inaccessible later -- useful only with -f -c, --bytes=N output the last N bytes -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 --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 -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 for 512, k for 1024, m for 1048576 (1 Meg). 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 bugs to <bug-coreutils@gnu.org>. COPYRIGHT
Copyright (C) 2002 Free Software Foundation, Inc. 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
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 tail should give you access to the complete manual. tail (coreutils) 4.5.3 February 2003 TAIL(1)
All times are GMT -4. The time now is 04:11 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy