parse a file to find an ip address

gurucg · 08-13-2007, 04:44 AM

hi,

i need an efficient shell script program that should parse a file to find all ip address within it and ping those ip to check whether they r reachable r not....

thanks,
gcg...

95se · 08-13-2007, 05:28 AM

Quote:

Originally Posted by gurucg

hi,

i need an efficient shell script program that should parse a file to find all ip address within it and ping those ip to check whether they r reachable r not....

thanks,
gcg...

Very quick and dirty, no bounds checking (that the parts are between 0-255).

Code:

for i in `cat $1 | grep '\b[0-9]\.[0-9]\.[0-9]\.[0-9]\b'`; ping $i; done

gurucg · 08-13-2007, 05:43 AM

hi ,
its giving an error
./t6: line 3: syntax error near unexpected token `ping'
./t6: line 3: `ping $line'

95se · 08-13-2007, 05:53 AM

Code:

for i in `cat $1 | grep '\b[0-9]\.[0-9]\.[0-9]\.[0-9]\b'`; do ping $i; done

You may have to kill ping by using C-c yourself too.

colucix · 08-13-2007, 06:10 AM

gurucg, just an hint: when testing a script put an echo in front of any command inside a loop, as in

Code:

for i in <some expression here>
do
   echo ping $i
done

in this way you can look at the resulting commands before actually execute them. The idea from 95se is good, but I'd use the following egrep command

Code:

egrep -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'

this matches 4 consecutive groups of digit separated by dot, with one to three digit each one. With the -o option egrep prints only the string matching the pattern, that is the parsed IP address.

/bin/bash · 08-13-2007, 06:16 AM

95se I couldn't get your regex to work?

This is what I came up with:
$for i in $(grep -Eo "[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}" yourfile);do ping -c2 -w2 $i;done

/bin/bash · 08-13-2007, 06:23 AM

Another way to do it:
grep -Eo "[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}" yourfile|
while read i;do
ping -c2 -w2 $i
done

gurucg · 08-13-2007, 07:07 AM

#
# Internet host table
#
127.100.100.1 localhost
129.0.0.1 b1-lr-09 loghost
10.42.76.1 b1-lr-09-e0 # ADD - DO NOT MODIFY
this is the contents of myfile(host1)..... even though i tried above code .... i am getting some errors.. so please help me out from this

gurucg · 08-13-2007, 07:08 AM

i am making use of solaris

gurucg · 08-13-2007, 07:11 AM

which book(or websites) do i refer for shell script programming .....

doublejoon · 08-13-2007, 08:29 AM

http://en.tldp.org/LDP/abs/html/

colucix · 08-13-2007, 10:29 AM

Indeed, the usage of regexp on solaris is a bit more restricted and grep/egrep has less options than their counterparts on linux. Parsing an host file as the one you posted could be done by simply

Code:

awk '{print $1}' | grep -v \#

or better (if it works)

Code:

awk '{print $1}' | grep ^[0-9]

By the way, both fail if the file you're parsing contains lines other than comments or IP address/hostname pairs.
Regarding a good shell programming guide, I would suggest the "Bash Guide for beginners" http://www.tldp.org/LDP/Bash-Beginne...tml/index.html, but it is based on the Bourne Again Shell and you may feel a little confused if you're working on solaris, since it implements the Bourne Shell /bin/sh. A lot of BASH features are not available in SH.

95se · 08-13-2007, 04:08 PM

Here. You may need to change the ping command, but hopefully this will work better for you.

Code:

#!/usr/bin/python

import sys, os, re

PING_COMMAND = "ping -c 3 -w 30"

def isalive(ip):
	ret = os.system(PING_COMMAND + " " + ip + " > /dev/null");
	if ret == 0:
		return True
	return False

commentPattern = re.compile('^\s*#')
ipPattern = re.compile('\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}')

for f in sys.argv[1:]:
	try:
		input = file(f, 'r')
	except IOError, e:
		print "Can't read from file " + f
		continue

	for line in input:
		if commentPattern.match(line):
			continue
		matches = ipPattern.finditer(line)
		for match in matches:
			ip = match.group()
			if isalive(ip):
				print ip + " up"
			else:
				print ip + " down"

Put it in a file named pinger.py, make it executable, then run it, with the file names as arguments.

gurucg · 08-14-2007, 12:22 AM

thanks it worked....

ghostdog74 · 08-14-2007, 01:30 AM

Quote:

Originally Posted by colucix

Code:

awk '{print $1}' | grep -v \#

or better (if it works)

Code:

awk '{print $1}' | grep ^[0-9]

awk is more than just that.

Code:

awk '!/#/{print $1}' file

Code:

awk '!/^[0-9]/{print}' file