Sponsored Content
Top Forums Shell Programming and Scripting Scan a file in realtime and execute certain commands on encountering 5 consecutive identical lines Post 302597111 by methyl on Thursday 9th of February 2012 08:11:24 AM
Old 02-09-2012
This appears to be a continuation of:
https://www.unix.com/shell-programmin...ignP=302596963

What does "tail -F" do on your Operating System? Not valid on mine. What Operating System and version do you have?

In general it is a major programming exercise to "tail -f" a file and carry out any further processing in a pipeline. There have been posts on this board which suggest using named pipes.
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Cutting n consecutive lines from a file...

Hi, I have this problem of separating 10 consecutive lines from a file, say starting from 21 to 30... I have used a filter like this.. head -n 30 myfile | tail -n 10 Is there a simpler way than this? (2 Replies)
Discussion started by: Vishnu
2 Replies

2. UNIX for Dummies Questions & Answers

How to scan only new lines added in file?

Hi, I am planning to implement a scheduled script that will go against my log files (every hour), search for a set of key words (errors, exceptions, faults etc). The script must be intelligent enough to scan only the new lines added to the log file since it last ran. I can use grep for... (3 Replies)
Discussion started by: redlotus72
3 Replies

3. Shell Programming and Scripting

merging of 2 consecutive lines in a file for a specific pattern

Hi , I'm looking for a way to merge two lines only for a given pattern / condition. Input : abcd/dad + -49.201 2.09 -49.5 34 ewrew rewtre * fdsgfds/dsgf/sdfdsfasdd + -4.30 0.62 -49.5 45 sdfdsf cvbbv * sdfds/retret/asdsaddsa + ... (1 Reply)
Discussion started by: novice_man
1 Replies

4. Shell Programming and Scripting

Find time difference between two consecutive lines in same file.

Hello I have a file in following format: IV 08:09:07 NM 08:12:01 IC 08:12:00 MN 08:14:20 NM 08:14:15 I need a script to compare time on each line with previous line and show the inconsecutive line. Ex.: 08:12:00 08:14:15 A better way... (6 Replies)
Discussion started by: vilibit
6 Replies

5. Shell Programming and Scripting

how to delete two consecutive lines from the file

Hi guys I am deleting a unique line from the file and also need to remove the line above it which is NOT unique and servers as a record separator. Here is an example: # 101 803E 823F 8240 # 102 755f 4F2A 4F2B # 290 747D 0926 0927 # 999 8123 813E ... (5 Replies)
Discussion started by: aoussenko
5 Replies

6. Shell Programming and Scripting

finding and removing 2 identical consecutive words in a text

i want to write a shell script that correct a text file.for example if i have the input file: "john has has 2 apples anne has 3 oranges oranges" i want that the output file be like this: "john has 2 apples anne has 3 oranges" i've tried to read line by line from input text file into array... (11 Replies)
Discussion started by: cocostaec
11 Replies

7. Shell Programming and Scripting

Removing consecutive lines in a file

We have very large transaction logs that have transactions which start with a line that starts with 'Begin :' and ends with a line that starts with 'End :'. For most transactions there is valid data between those two lines. I am trying to get rid of lines that look like this: Begin :... (11 Replies)
Discussion started by: deneuve01
11 Replies

8. UNIX for Dummies Questions & Answers

Delete 26 consecutive lines in a file

I have a text file that is about 90,000 lines long. How would I delete lines 64-89, 152-177, 240-265, 328-353... etc? The sections I would like to delete are 26 lines long and the number of lines between the sections I would like to delete is 62 lines. Thanks very much in advance. (6 Replies)
Discussion started by: MDeBiasse
6 Replies

9. Shell Programming and Scripting

Grep 2 consecutive lines and replace the second line in a file

I have a file lake this cat ex1.txt </DISCOUNTS> <B2B_SPECIFICATION elem="0"> <B2B_SPECIFICATION elem="0"> <DESCR>Netti 2 </DESCR> <NUMBER>D02021507505</NUMBER> </B2B_SPECIFICATION> <B2B_SPECIFICATION elem="1"> <DESCR>Puhepaketti</DESCR>... (2 Replies)
Discussion started by: Dhoni
2 Replies

10. UNIX for Beginners Questions & Answers

awk - If field value of consecutive records are the identical print portion of lines

I have some data that looks like this: PXD= ZW< 1,6 QR> QRJ== 1,2(5) QR> QRJ== 4,1(2) QR> QRJ== 4,2 QRB= QRB 4,2 QWM QWM 6,2 R<C ZW< 11,2 R<H= R<J= 6,1 R>H XZJ= 1,2(2) R>H XZJ= 2,6(2) R>H XZJ= 4,1(2) R>H XZJ= 6,2 RDP RDP 1,2 What I would like to do is if fields $1 and $2 are... (5 Replies)
Discussion started by: jvoot
5 Replies
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)
All times are GMT -4. The time now is 08:55 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy