CODEWITHSUNDEEP
arraysregexbashsed
dig_123
dig_123

Reputation: 2368

variable expansion as a pattern in sed not working

I've a simple script to set several parameters in /etc/ssh/sshd_config :

#! /bin/bash

declare -a param=('Banner' 'ClientAliveInterval' 'ClientAliveCountMax' 'Ciphers' \
'PermitUserEnvironment' 'PermitEmptyPasswords' 'PermitRootLogin' \
'HostbasedAuthentication' 'IgnoreRhosts' 'MaxAuthTries' \
'X11Forwarding' 'LogLevel'\
)

declare -a val=('/etc/issue.net' '300' '0' 'aes128-ctr,aes192-ctr,aes256-ctr' \
'no' 'no' 'no' 'no' 'yes' '4' 'no' 'INFO' \
)

for (( i=0;i<12;i++ ))
do
 #echo "${param[$i]} ${val[$i]}"
  egrep "^[ #]*${param[$i]}.*" /etc/ssh/sshd_config &> /dev/null
   if [ $? -eq 0 ];
    then
       sed -i "s|^[ #]*\$param[$i].*|${param[$i]} ${val[$i]}|1" /etc/ssh/sshd_config
  else
       echo "${param[$i]} ${val[$i]}" >> /etc/ssh/sshd_config
  fi
done;

However the variable expansion in sed pattern match is not working as desired:

sed -i "s|^[ #]*\$param[$i].*|${param[$i]} ${val[$i]}|1" /etc/ssh/sshd_config

Can someone help me. My array expansion and everything in the script is fine though. I've checked the same with an echo printout.

Upvotes: 2

Views: 158

Answers (1)

anubhava
anubhava

Reputation: 785256

Not sure why you have $ escaped, and to access array element you need to use ${param[$i]}.

You can use:

sed -i "s~^[ #]*${param[$i]}.*~${param[$i]} ${val[$i]}~1" /etc/ssh/sshd_config

btw ^[ #]* will only match space or # at line start.

Upvotes: 1

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