Sponsored Content
Top Forums UNIX for Beginners Questions & Answers How to use cat grep and cut together? Post 303044564 by synack on Wednesday 26th of February 2020 12:56:31 PM
Old 02-26-2020
Quote:
Originally Posted by RudiC
There's NO string like "reached" in your samples, nor semicolons. Those don't show up in my host calls, either. Replace ! /^Host/ with /domain/ or /name/ or /pointer/. If that doesn't help, show your input data.


cat is by no means needed in any of your attempts as both grep and cut can open files by themselves, or you can redirect stdin for them.
grepping the first number is quite easy, like

Code:
$ host 82.165.230.17 | grep -o "^[^.]*"
17

, but extracting the remote hostname not so as you don't know what the FQDN looks like. The nearest I get is

Code:
$ host 82.165.230.17 | grep -oE "^[^.]*| [^. ]*\."
17
 bap.

Yes you are right. it's my fault. There somes lines that i didn't see in the original file, like ";; connection timed out; no servers could be reached"


thank you for your explanation and your help.
 

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

cat and grep not working

I am trying to cat a file and then grep that file for a number. I can do it fine on other files but this particular file will not do anything. I tried running it on an older file from the same device but it is just not working. The file is nothing more than a flat file on a unix box. Here is just a... (3 Replies)
Discussion started by: jphess
3 Replies

2. UNIX for Dummies Questions & Answers

cat, grep and tee to a local file

Hi, This is what I am trying to do. 1) connect to 3 remote servers from my local machine serverA serverB serverC 2) read error file from each server cat /var/lib/mysql/mydb.err 3) grep for lines displaying "yesterday" date grep "`date +%y%m%d' '-d\"1 day ago\"`" 4) Append those lines to a... (7 Replies)
Discussion started by: shantanuo
7 Replies

3. Shell Programming and Scripting

cat or cut to delimit csv?

Hi, Im a pretty large noob to linux/perl etc and im trying to use mysql slurp to take a delimited file and import it into mysql using stdin (in the hope its faster) mysqlslurp - slurp <STDIN> into a MySQL table - search.cpan.org Christopher Brown / MySQL-Slurp - search.cpan.org Using... (3 Replies)
Discussion started by: newtony
3 Replies

4. Shell Programming and Scripting

cat /etc/passwd and grep -v on /etc/shells

Hi All, I'd like to do this cat /etc/passwd and grep -v on the /etc/shells list I'd like to find all shell that doesn't exist on the /etc/passwd. Is there an easy way without doing a egrep -v "/bin/sh|/bin/bash................"? How do I use a file /etc/shells as my list for... (4 Replies)
Discussion started by: itik
4 Replies

5. Shell Programming and Scripting

cat -n and grep

I am not sure if using cat -n is the most efficient way to split a file into multiple files, one file per line in the source file. I thought using cat -n would make it easy to process the file because it produces an output that numbers each line that I could then grep for with the regex "^ *$i".... (3 Replies)
Discussion started by: kapu
3 Replies

6. Shell Programming and Scripting

grep or cat using sed

Is there a way using grep or cat a file to create a new file based on whether the first 9 positions of each record is less than 399999999? This is a fixed file format. (3 Replies)
Discussion started by: ski
3 Replies

7. Slackware

How should I cut this line using cut and grep?

not sure how to do it. wan't to delete it using cut and grep ince i would use it in the shell. but how must the command be? grep "64.233.181.103 wwwGoogle.com" /etc/hosts | cut -d the delimeter is just a space. can you help meplease. :D (1 Reply)
Discussion started by: garfish
1 Replies

8. UNIX for Dummies Questions & Answers

Grep and cat combined

Hello, i need to search one word (snp1) from many files and copy the content of the columns of this word in new file. example: file 1: SNP BP CHR P snp1 1 3 0.01 snp2 2 2 0.05 . . file 2: SNP BP CHR P snp1 1 3 0.06 snp2 2 2 0.3 output... (6 Replies)
Discussion started by: biopsy
6 Replies

9. Shell Programming and Scripting

Replace cat and grep with <

Hello someone told me to use OS=`awk '{print int($3)}' < /etc/redhat-release` instead of OS=cat /etc/redhat-release | `awk '{print int($3)}'` any idea for the reason ? (5 Replies)
Discussion started by: nimafire
5 Replies

10. UNIX for Dummies Questions & Answers

Grep or cat The Whole Directory PROBLEMS :(

Hi Guys This is my first post so I am not sure how things go here. I'm sorry if I'm breaking the rule or something. Feel free to correct me about that :) So as I was saying... I'd been trying to grep this folder containing 900,000 txt files but seems no luck. I get either "No such file... (6 Replies)
Discussion started by: Nexeu
6 Replies
LOGTOP(1)						      General Commands Manual							 LOGTOP(1)

NAME
logtop - Realtime log line rate analyser SYNOPSIS
logtop [OPTIONS] DESCRIPTION
logtop is a System Administrator tool analyzing line rate on stdin. It reads on stdin and print a constantly updated result displaying, in columns: Line number, count, frequency, and the actual line. $ tail -f FILE | logtop is the friendly version of: $ watch 'tail FILE | sort | uniq -c | sort -gr' OPTIONS
-s, --size=K Only keep K lines in memory, instead of 10000. -q, --quiet Do not display a live view of the data, only display a top at exit. -l, --line-by-line=K Print result line by line, in a machine friendly format, K is the number of result to print per line. Line by line format is : [%d %f %s ]* %d : Number of occurences %f : Frequency of apparition %s : String (Control chars replaced by dots. -i, --interval=K Interval between graphical updates, in seconds. Defaults to 1. -h, --help Show summary of options. -v, --version Show version of program. EXAMPLES
Here are some logtop usage examples. tail -f cache.log | grep -o "HIT|MISS" | logtop Realtime hit / miss ratio on some caching software log file. tail -f access.log | cut -d' ' -f1 | logtop -s 10000 Realtime most querying IPs on your server, as long as log lines in access.log starts with the client IP. tail -f access.log | cut -d' ' -f7 | logtop -s 10000 Realtime most requested web pages in a NCSA like log file. cat auth.log | grep -v "CRON" | grep -o ": .*" | logtop -q -s 100000 Display a one-shot simple analyse of your auth.log. SEE ALSO
watch(1) AUTHOR
logtop was written by Julien Palard. This manual page was written by Julien Palard <julien@palard.fr>, for the Debian project (and may be used by others). April 16, 2011 LOGTOP(1)
All times are GMT -4. The time now is 11:13 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy