Sponsored Content
Top Forums UNIX for Advanced & Expert Users How to alert if no output from tail -f command Post 302425805 by sharif on Sunday 30th of May 2010 11:02:36 AM
Old 05-30-2010
How to alert if no output from tail -f command

Hi Dears,
I am using AWK script to monitor some log files. My awk will get the input from the output of tail -f LOGFILE. (tail -f LOGFILE | myawkanalyzer)

My doubt is, How can I notify, if I didn't get any output from the tail -f command. i.e) Log file stuck for some reason. I want to display some alert message as "Log file stuck. blah blah"...

I hope my message is clear. Please excuse me if the info is not clear.

Regards,
Sharif.
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Output from tail to a user

Hi all I've read through a few of these lists but can't find a right combination of answers (I can create VPN's but can't send an email!) Ok - I'm using taper as backup software which generates a log file called taper_log I want the last eight lines of this log file to be sent to a specified... (3 Replies)
Discussion started by: ifan
3 Replies

2. Shell Programming and Scripting

piping output of tail running in background

Not sure why this does not work in bash: tail -f err.log |& -bash: syntax error near unexpected token `&' I am attempting to continuously read a file that is being updated by doing a "tail -f" on the file and piping the output to stdin which can then be read by the next shell command Thnx (4 Replies)
Discussion started by: anuramdas
4 Replies

3. UNIX for Dummies Questions & Answers

AWK Output not working with tail -f

Hi , I have Continuous updating log file. I want to continuously scan that file using "tail -f " and execute a shell command like "date" command when that particular keyword is detected . I am using awk to acheive it but not suceeded so far. However when I use "cat" instead of tail -f this... (3 Replies)
Discussion started by: scott_tiger
3 Replies

4. Shell Programming and Scripting

how to read tail -F command output in perl

Hi All, How I will read the output of the tail -F command in perl. I have text file with below contains file1.txt 1 2 3 4 $running=1; sub openLog($) { (my $log) = @_; (1 Reply)
Discussion started by: pravin27
1 Replies

5. Shell Programming and Scripting

copy tail output to an external file in perl

The below code works to tail client.log file. but I want to copy the output into an external file /home/tail.txt Can anyone please help. #!/opt/bin/perl -w open my $pipe, "-|", "/usr/bin/tail", "/var/log/client.log" or die "could not start tail on /var/log/client.log : $!"; print while... (2 Replies)
Discussion started by: sureshcisco
2 Replies

6. Shell Programming and Scripting

tail command help

Hi does anyone know how to create a file using the tail command? My book has this file I need to create and it says to use the tail command and that it is possible but I have no idea. Thanks. (4 Replies)
Discussion started by: drew211
4 Replies

7. Shell Programming and Scripting

Weird tail output over ssh

Hello; Am trying to correct the formatting of tail output over ssh. Using the following code: echo "" > $FILE for BOX in $SERVERS do echo "Processing on $BOX" |tee -a $FILE echo "===============================" >> $FILE sudo ssh $BOX 'TERMINAL="vt100" /usr/bin/sh -s' <... (2 Replies)
Discussion started by: delphys
2 Replies

8. Shell Programming and Scripting

Count lines and words of a stream output with tail

Hello, I need to tail -f a file output stream and I need to get only lines that contains "get" and "point" in the same line. It doesn't matter the order. Then I need only the text BEFORE "point". I have to count each line and perform other serveral actions after this has performed 3 times.... (9 Replies)
Discussion started by: Kibou
9 Replies

9. UNIX for Dummies Questions & Answers

Tail -f | grep > output.txt

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)
Discussion started by: LaUs3r
3 Replies

10. Shell Programming and Scripting

When redirecting tail -F output fail after log rotation?

Redirecting the tail output fails when log rotation happens even though i have used -F. But when i tail and see the output on terminal this does not happen. Note i have also used & to execute this statement in background. Suppose if i want to tail a file /opt/SAMPLE.txt and redirect its output... (1 Reply)
Discussion started by: CN1
1 Replies
TAIL(1) 						    BSD General Commands Manual 						   TAIL(1)

NAME
tail -- display the last part of a file SYNOPSIS
tail [-f | -F | -r] [-b number | -c number | -n number] [file ...] DESCRIPTION
The tail utility displays the contents of file or, by default, its standard input, to the standard output. The display begins at a byte, line or 512-byte block location in the input. Numbers having a leading plus (``+'') sign are relative to the beginning of the input, for example, ``-c +2'' starts the display at the second byte of the input. Numbers having a leading minus (``-'') sign or no explicit sign are relative to the end of the input, for example, ``-n 2'' displays the last two lines of the input. The default starting location is ``-n 10'', or the last 10 lines of the input. The options are as follows: -b number The location is number 512-byte blocks. -c number The location is number bytes. -f The -f option causes tail to not stop when end of file is reached, but rather to wait for additional data to be appended to the input. The -f option is ignored if the standard input is a pipe, but not if it is a FIFO. -F The -F option is the same as the -f option, except that every five seconds tail will check to see if the file named on the command line has been shortened or moved (it is considered moved if the inode or device number changes) and, if so, it will close the current file, open the filename given, print out the entire contents, and continue to wait for more data to be appended. This option is used to follow log files though rotation by newsyslog(8) or similar programs. -n number The location is number lines. -r The -r option causes the input to be displayed in reverse order, by line. Additionally, this option changes the meaning of the -b, -c and -n options. When the -r option is specified, these options specify the number of bytes, lines or 512-byte blocks to display, instead of the bytes, lines or blocks from the beginning or end of the input from which to begin the display. The default for the -r option is to display all of the input. If more than a single file is specified, each file is preceded by a header consisting of the string ``==> XXX <=='' where ``XXX'' is the name of the file. The tail utility exits 0 on success, and >0 if an error occurs. SEE ALSO
cat(1), head(1), sed(1) STANDARDS
The tail utility is expected to be a superset of the IEEE Std 1003.2-1992 (``POSIX.2'') specification. In particular, the -b, -r and -F options are extensions to that standard. The historic command line syntax of tail is supported by this implementation. The only difference between this implementation and historic versions of tail, once the command line syntax translation has been done, is that the -b, -c and -n options modify the -r option, i.e. ``-r -c 4'' displays the last 4 characters of the last line of the input, while the historic tail (using the historic syntax ``-4cr'') would ignore the -c option and display the last 4 lines of the input. HISTORY
A tail command appeared in Version 7 AT&T UNIX. BUGS
When using the -F option, tail will not detect a file truncation if, between the truncation and the next check of the file size, data written to the file make it larger than the last known file size. BSD
June 6, 1993 BSD
All times are GMT -4. The time now is 05:12 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy