I want to run tail -f to continuously monitor a log file, outputing a specific field to a second log file. I can get the first portion to work with the following command:
tail -f log | awk '{if ($1 == "Rough") print $5}'
also:
awk '{if ($1 == "Rough") print $5}' <(tail -f log)
The... (2 Replies)
Hello,
I am too daft to remember how to properly feed numbers that I've extracted with awk(1) to tail(1).
The actual question is probably a lot more simple than the context, but let me give you the context anyway:
I've just received some email that was sent with MS Outlook and arrived in... (8 Replies)
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)
Hi Folks,
I have a log that contains data as shown below:
11:59:43,144 (1,850) Signal : ....
11:59:44,109 (1850) Bps : .....
I wish to remove "" from all lines and it is on the start of every line. I have achieved that successfully using the command:
tail -f imp.log | sed 's/\... (4 Replies)
Hi, I only have a very limited understanding and experience with writing code and I was hoping I could get some help.
I have a dataset of two columns (txt format, numbers in each row separated by a tab)
Eg.
1 5
2 5
3 6
4 7
5 6
6 6
7 ... (5 Replies)
Hi,
I had few scripts which were running fine on linux:
uname -a
Linux ######### 2.6.9-89.ELsmp #1 SMP Mon Apr 20 10:33:05 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux
from some front end application. Recently there was a migration of this application on some other linux m/c:
uname -a... (4 Replies)
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)
Hello,
When I am trying to use tail +13 filename.csv it is throwing an error.
tail: cannot open `+13' for reading: No such file or directory and then prints last 10 lines of the file. (File is present on the path)
But when i try tail -13 filename.csv it runs perfectly.
Could I have... (5 Replies)
Hi,
I want to do file format using awk script, for that i wan to use 'tail'. Here is the scenario. I will be having set of files in a directory. Those files i need to write to another directory with same file name, but while writing the file to out directory, i need to write the last line as... (3 Replies)
Hello,
I am trying to create an iptables script with tail ,sed and awk.
1st Request: Search keyword "secret" in access.log file
2nd Request: Get first column matching lines (ip address)
3rd Request: Save it to a file
This is what I did so far:
grep.sh
#!/bin/bash
while true;
do
tail... (23 Replies)
Discussion started by: baris35
23 Replies
LEARN ABOUT MOJAVE
tail
TAIL(1) BSD General Commands Manual TAIL(1)NAME
tail -- display the last part of a file
SYNOPSIS
tail [-F | -f | -r] [-q] [-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 start-
ing 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.
-q Suppresses printing of headers when multiple files are being examined.
-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 unless -q flag is specified.
EXIT STATUS
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 29, 2006 BSD