Sponsored Content
Full Discussion: using "tail -f" in script
Top Forums UNIX for Dummies Questions & Answers using "tail -f" in script Post 302423051 by ikeQ on Thursday 20th of May 2010 05:05:13 AM
Old 05-20-2010
I want to put `tail -f filename | grep -i -E 'error|warning'` into a variable and construct an e-mail that report any lines that contain "error" or "warning", after that, I will send the mail to the address specified in the RECIPIENT shell variable which is defined within the script.

I have tried `tail -f filename | grep -i -E 'error|warning'` in the terminal, there is no problem that it displayed last(sorry it is not the 'first' I just posted) 10 lines of the file which contain "error" and "warning" firstly, and then wait for the file to grow and check the next line if it is contain the keywords.

also , the `grep -i -E 'error|warning'`, is it correct that it can grep all the "error" or "warning" in any combination of upper and lower case letters?

Thanks!
 

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

script not working after "tail -f"

Hi Everyone , I am facing a strange problem i have made the follwing script to watch a appending log file (abc.log) but its not moving after the line tail -f , any suggestions ===================================== #!/bin/bash while true do tail -f abc.log | grep "exceptions" echo hi... (12 Replies)
Discussion started by: xander
12 Replies

2. Shell Programming and Scripting

Perl - immitate perpetual "tail"

Is there some way I can have a script monitor the newest line of a log file until a certain entry gets placed in the log? Basically I want to start this script, and have it spit up the last 10 lines or so to a browser via AJAX... the AJAX is not my problem though, as I have no idea how to go... (4 Replies)
Discussion started by: jjinno
4 Replies

3. UNIX for Dummies Questions & Answers

Explain the line "mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`"

Hi Friends, Can any of you explain me about the below line of code? mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'` Im not able to understand, what exactly it is doing :confused: Any help would be useful for me. Lokesha (4 Replies)
Discussion started by: Lokesha
4 Replies

4. Shell Programming and Scripting

awk command to replace ";" with "|" and ""|" at diferent places in line of file

Hi, I have line in input file as below: 3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL My expected output for line in the file must be : "1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL" Can someone... (7 Replies)
Discussion started by: shis100
7 Replies

5. UNIX for Dummies Questions & Answers

"tail -n 1 filename" error while "head -n 1 filename" is ok?

Hi all, I was wondering why tail -n 2 filename produce an error when I manage to do similar command on head -n 2 filename SunOS{type8code0}: tail -n 2 filename usage: tail ] tail ] (2 Replies)
Discussion started by: type8code0
2 Replies

6. UNIX for Dummies Questions & Answers

"Help with bash script" - "License Server and Patch Updates"

Hi All, I'm completely new to bash scripting and still learning my way through albeit vey slowly. I need to know where to insert my server names', my ip address numbers through out the script alas to no avail. I'm also searching on how to save .sh (bash shell) script properly.... (25 Replies)
Discussion started by: profileuser
25 Replies

7. UNIX for Dummies Questions & Answers

Using "mailx" command to read "to" and "cc" email addreses from input file

How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address and column 3 contains “cc” e-mail address to include with same email. Sample input file, email.txt Below is an sample code where... (2 Replies)
Discussion started by: asjaiswal
2 Replies

8. Shell Programming and Scripting

Bash script - Print an ascii file using specific font "Latin Modern Mono 12" "regular" "9"

Hello. System : opensuse leap 42.3 I have a bash script that build a text file. I would like the last command doing : print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt where : print_cmd ::= some printing... (1 Reply)
Discussion started by: jcdole
1 Replies

9. AIX

Apache 2.4 directory cannot display "Last modified" "Size" "Description"

Hi 2 all, i have had AIX 7.2 :/# /usr/IBMAHS/bin/apachectl -v Server version: Apache/2.4.12 (Unix) Server built: May 25 2015 04:58:27 :/#:/# /usr/IBMAHS/bin/apachectl -M Loaded Modules: core_module (static) so_module (static) http_module (static) mpm_worker_module (static) ... (3 Replies)
Discussion started by: penchev
3 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 implies the -f option, but tail will also check to see if the file being followed has been renamed or rotated. The file is closed and reopened when tail detects that the filename being read from has a new inode number. The -F option is ignored if reading from standard input rather than a file. -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. DIAGNOSTICS
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 -F, -b and -r 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 PWB UNIX. BSD
June 6, 1993 BSD
All times are GMT -4. The time now is 06:55 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy