Shell Programming and Scripting

I'm trying to figure out how to basically replace a line in a text file using Sed. Here's what I need sed to do:

I have a file with passwords that are in use. Each month the passwords need to be swapped out with passwords stored in another file. I want to use Sed (or Awk ... or possibly both) to replace just the password section (look below).

pass:2432hkh49ncs9s <-- (I want to replace everything after the : delimiter )
7daypass:9g8ehv24v83hqs
99daypass:u4hkhv2.9zf67a

Ideally I would just like to make the line blank and then replace it with my password string. What I've tried so far is something like this:

sed 1s/pass:/ <--Then what I want to do is replace everything after pass:

I'm not sure if I've provided enough info, but any help would be greatly appreciated, thanks!

Assumeing your new password file is formated with one password per line, something like this could work:

Code:

#!/bin/bash - 
# 
 
i=1 
lines=$(cat passfile | wc -l)   

while [ $i -le $lines ] ; do   
   pass=$(awk 'BEGIN { FS = "\n" ; RS = "" } { print '\$$i'  }' passlist)  
   sed -n ""$i"s/:.*/:$pass/pg" passfile 
   ((i++)) 
done

I guess I should've probably used a for loop, either or I guess:

Code:

#!/bin/bash - 
#  

for (( i = 1 ; i <= $(cat passfile | wc -l) ; i++))
   do
    pass=$(awk 'BEGIN { FS = "\n" ; RS = "" } { print '\$$i'  }' passlist)      
    sed -n ""$i"s/:.*/:$pass/pg" passfile
done

Thanks, that was exactly what I needed.

You're welcome.