grep multiple pattern from read input - bash

so i made a bash script the greps the name of the host on the redirected file. However, there are hosts that are named either with "-" or "_"
GTR_SRV123_EST
GTR-SRV123-EST
Right now, what i did was, grep just a portion of the FQDN, like SRV123
Is there a way i can grep the host even if i just put the FQDN GTR_SRV123_EST and it will still matched this GTR-SRV123-EST.
i have a prompt that ask for the hostname:
echo -n "Please enter the host: "
read $host
grep -i $host ${temp}/*
update:
so had it working with the help of Juan's command. However, the directory path is displayed on the output. How can i get rid of it.
/export/home/aa12s/GLB-TXU/temp/
Current output:
/export/home/aa12s/GLB-TXU/temp/GBL-ASA-A:100022FBC0D00038 gbl-asa-a-mode1 5005076801103673 active gbl-ac-wbg02
Desired output:
GBL-ASA-A:100022FBC0D00038 gbl-asa-a-mode1 5005076801103673 active gbl-ac-wbg02
Command:
grep -iE "$(echo $host| awk -F '/export/home/aa12s/GLB-TXU/temp/' '{$2=$1;a=gsub(/_/, "-",$2); print $1"|"$2}' 2>/dev/null)" ${temp}/*

Edit your pattern.
echo -n "Please enter the host: "
read host # Edit: not $host
host="${host//[_-]/\[_-\]}" # turn either into a *check* for either
grep -i "$host" ${temp}/*

Kind of hacky but give this a try:
grep -Ei "$(echo $host| awk '{$2=$1;gsub(/_/, "-",$2);print $1"|"$2}' 2>/dev/null)" ${temp}/*
To get rid of filepaths:
grep -iE "$(echo $host| awk '{$2=$1;gsub(/_/, "-",$2);print $1"|"$2}' 2>/dev/null)" ${temp}/* 2>/dev/null|awk -F \/ '{print $NF}'
NOTE: Slashes must NOT be present in the file content.

If there is no host name with both _ and - below will work.
Entered host contains only _
grep -iE $(echo $host | tr "_" "-")\|$host ${temp}/*
Entered host contains only -
grep -iE $(echo $host | tr "-" "_")\|$host ${temp}/*
Entered host contains both _ and -
grep -iE $(echo $host | tr "_" "-")\|$(echo $host | tr "-" "_")\|$host ${temp}/*

You can use backreference :
([_-]) : capture either _ ou - in group 1
\1 : reference group 1
try this command :
grep -iE "([_-])$host\1" ${temp}/*
https://regex101.com/r/uH5SHC/1/
Wiyh host=SRV123, you will capture :
GTR_SRV123_EST
GTR-SRV123-EST
and not
GTR_SRV123-EST

Related

Check ip is present within file & update iptables bash script

I want to check that the ip is present within the ccd folder and push the ip route to the FORWARDING chain in the iptables. Im new to bash scripting and need a little help finishing this script.
client file in /etc/openvpn/ccd :
ifconfig-push 10.8.0.45 255.255.255.0
push 'route 10.10.0.45'
I need to grep 10.8.0.45 & 10.10.0.45
and push those routes in the iptables.
e.g
iptables -A FORWARD -s 10.8.0.45 -d 10.10.0.45 -j ACCEPT
client-connect /etc/openvpn/on_connect.sh
script I need help with 'grep' or 'awk'
static_ip= cat $CCD_DIR/$common_name | grep -w "ifconfig-push" | awk -F ' ' {'print $2'}
ip_destination=cat $CCD_DIR/$common_name | grep -w "push 'route" | awk -F ' ' {'print $3'} | tr -d "'"
#!/usr/bin/env bash
#
# Add iptables rules based on CCD client config.
#
CCD_DIR="/etc/openvpn/ccd"
RULE_COMMENT="FORWARD"$common_name
static_ip=cat $CCD_DIR/$common_name | grep -w "ifconfig-push" | awk -F ' ' {'print $2'}.
ip_destination=cat $CCD_DIR/$common_name | grep -w "push 'route" | awk -F ' ' {'print $3'} | tr -d "'"
if [ -f $CCD_DIR/$common_name ]; then
sudo iptables -A FORWARD -s $static_ip -d ip_destination -j ACCEPT
fi
exit 0
Edit: I think my usage of cat is wrong .
Try like this.
static_ip=$( cat $CCD_DIR | grep -oE "\b([0-9]{1,3}\.){3}[0-9]{1,3}\b" | grep -E '(^|\s)10.8.0.45($|\s)' )
ip_destination=$( cat $CCD_DIR | grep -oE "\b([0-9]{1,3}\.){3}[0-9]{1,3}\b" | grep -E '(^|\s)10.10.0.45($|\s)' )
So first you grep all IP's address in file and then you search exactly what you need
Edited after your comment.
If I understand correctly,
"ifconfig-push" - Is only one peer ccd file ?
so you can use this :
static_ip=$( grep -w "ifconfig-push" | awk -F ' ' {'print $2'})
For the rest in "push route" you need to use loop to find all matching ip address and put them to the iptables.
if [ -f $CCD_DIR/$common_name ]
then
cat $CCD_DIR | awk -F 'route' {'print $2'} | awk -F ' ' {'print $1'} | sed '/^$/d' | grep -E "\b(10)\.(8)\.(0)\.|(10)\.(10)\.(0).\b" | while read ip_destination
do
sudo iptables -A FORWARD -s $static_ip -d ip_destination -j ACCEPT
done
fi

Bash is redirecting output from command only after script has finished

Context
Got a daft script that checks a process is running on a group of hosts, like a watchdog, as I say it's a daft script so bear in mind it isn't 'perfect' by scripting standards
Problem
I've ran bash -x and can see that the script finishes its first check without actually redirecting the output of the command to the file which is very frustrating, it means each host is actually being evaluated to the last hosts output
Code
#!/bin/bash
FILE='OUTPUT'
for host in $(cat /etc/hosts | grep webserver.[2][1-2][0-2][0-9] | awk {' print $2 ' })
do ssh -n -f $host -i <sshkey> 'ps ax | grep myprocess | wc -l' > $FILE 2> /dev/null
cat $FILE
if grep '1' $FILE ; then
echo "Process is NOT running on $host"
cat $FILE
else
cat $FILE
echo "ALL OK on $host"
fi
cat $FILE
done
Script traceback
++ cat /etc/hosts
++ awk '{ print $2 }'
++ grep 'webserver.[2][1-2][0-2][0-9]'
+ for host in '$(cat /etc/hosts | grep webserver.[2][1-2][0-2][0-9] | awk {'\'' print $2 '\''})'
+ ssh -n -f webserver.2100 -i <omitted> 'ps ax | grep myprocess | wc -l'
+ cat OUTPUT
+ grep 1 OUTPUT
+ cat OUTPUT
+ echo 'ALL OK on webserver.2100'
ALL OK on webserver.2100
+ cat OUTPUT
+ printf 'webserver.2100 checked \n'
webserver.2100 checked
+ for host in '$(cat /etc/hosts | grep webserver.[2][1-2][0-2][0-9] | awk {'\'' print $2 '\''})'
+ ssh -n -f webserver.2101 -i <omitted> 'ps ax | grep myprocess | wc -l'
+ cat OUTPUT
2
+ grep 1 OUTPUT
+ cat OUTPUT
2
+ echo 'ALL OK on webserver.2101'
ALL OK on webserver.2101
+ cat OUTPUT
2
+ printf 'webserver.2101 checked \n'
webserver.2101 checked
Issue
As you can see, it's registering nothing for the first host, then after it is done, it's piping the data into the file, then the second host is being evaluated for the previous hosts data...
I suspect its to do with redirection, but in my eyes this should work, it doesn't so it's frustrating.
I think you're assuming that ps ax | grep myprocess will always return at least one line (the grep process). I'm not sure that's true. I'd rewrite that like this:
awk '/webserver.[2][1-2][0-2][0-9]/ {print $2}' /etc/hosts | while IFS= read -r host; do
output=$( ssh -n -f "$host" -i "$sshkey" 'ps ax | grep "[m]yprocess"' )
if [[ -z "$output" ]]; then
echo "Process is NOT running on $host"
else
echo "ALL OK on $host"
fi
done
This trick ps ax | grep "[m]yprocess" effectively removes the grep process from the ps output:
the string "myprocess" matches the regular expression "[m]yprocess" (that's the running "myprocess" process), but
the string "[m]yprocess" does not match the regular expression "[m]yprocess" (that's the running "grep" process)

How to make grep not interpret special characters in my search string?

When executing ./test.sh 12.34, the grep should match 12.34 and not 12-34. How can this be accomplished?
#!/bin/sh
ip=$1
echo $ip
if netstat | grep ssh | grep $ip; then
netstat | grep ssh | grep $ip
else
echo 'No'
fi
You could use grep with the -F option:
From man grep:
-F, --fixed-strings
Interpret pattern as a set of fixed strings (i.e. force grep to
behave as fgrep).
Your example:
grep -F "$ip"
grep using regex to match strings. . is a special character in regex, so it needs to be escaped. There is a rather elegant way of doing this:
export escaped_ip_addr = $(echo $ip_addr | sed "s/\./\\\./g")
Which would make your final code:
#!/bin/sh
#test.sh
ip=$1
echo $ip
export escaped_ip = $(echo $ip | sed "s/\./\\\./g")
if netstat | grep ssh | grep $escaped_ip; then
netstat | grep ssh | grep $escaped_ip
else
echo 'No'
fi

Bash output to multiple variales

I'm creating a script in Bash to change all MAC addresses of my PC. I can list all network interfaces with this:
ip link | grep "<" | cut -d " " -f 2 | cut -d ":" -f 1 | grep -v lo
And the output of the script is:
eth0
wlan0
Now I need to create a variable for each network interface (to use it in the future), but I don't know how, and Google didn't help me...
Answer:
readarray -t interfaces < <(ip link | grep "<" | cut -d " " -f 2 | cut -d ":" -f 1 | grep -v lo)
echo "${interfaces[0]}" # prints eth0
echo "${interfaces[1]}" # prints wlan0
And to loop over them use for:
for curInterface in "${interfaces[#]}"; do
echo "$curInterface"
done
But there are better ways to parse data:
First of all, instead of grepping < character you can use -o flag. This will output all of the data on single lines. Then you simply need the second word without : character. This is very simple in pure bash:
interfaces=()
while read -r _ curInterface _; do
interfaces+=("${curInterface%:}")
done < <(ip -o link)
Store the output in an array:
interfaces=( $(ip link | awk '/</ { print $2 }' | awk -F: '!/lo/ {print $1}') )
You can create an array from this output, and loop through it after.
my_array=( $(ip link | grep "<" | cut -d " " -f 2 | cut -d ":" -f 1 | grep -v lo) )
You can also this exmaple giving different alternatives redirect output to array
And I could have it simpler like this with one awk command:
readarray -t youravar < <(exec ip link | awk -F': ' '/^[0-9]+:/&&!/ lo: /{print $2}')

Bash new variable with other variable

I get the ip address like that :
Ip=`ifconfig | grep inet | grep -v -E 'inet6|127.0.0.1' | \
tr -d [:alpha:] | tr -s [:space:] | cut -d: -f2`
I have an ip like this for instance : 10.1.0.76
I want to make a new variable with the Ip variable to have another ip, for instance my new variable will return : 10.1.0.178
Just the last number change, so I want to get just a part of Ip variable (10.1.0.) and add another number to the end.
I tried with sed but I always have mistakes like "there's no file call'd ..."
Can you help me ?
You can use parameter expansion: It's simply: ${Ip%.*}.178
${Ip%.*} is the ip with the last dot and everything after it removed. The .178 is what you want to append after that.
Here it is in context:
# Your original expression
Ip=`ifconfig | grep inet | grep -v -E 'inet6|127.0.0.1' | \
tr -d [:alpha:] | tr -s [:space:] | cut -d: -f2`
# assign a new variable with the ip with different end octet
newIp=${Ip%.*}.178
# Show new ip
echo "$newIp"
Well, given that you have IP in a format x.y.z.w, you can use perl regex:
$ echo "120.20.31.78" | perl -pe 's/(.*)\..*/$1\.123/'
120.20.31.123
This will repace last number ("78") with "123".
So, in your case (assuming your "Ip" variable is set correctly), it would be:
Ip=ifconfig | grep inet | grep -v -E 'inet6|127.0.0.1' | tr -d [:alpha:] | tr -s [:space:] | cut -d: -f2 | perl -pe 's/(.*)\..*/$1\.123/'
see this, I hope it is what you want:
kent$ echo $ip
10.1.0.76
kent$ echo $part
178
kent$ sed -r "s/(.*\.).*/\1$part/" <<< $ip
10.1.0.178
to set $ip with new value:
kent$ ip=$(sed -r "s/(.*\.).*/\1$part/" <<< $ip)
kent$ echo $ip
10.1.0.178

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