Shell Programming and Scripting

How to confirm whether a particular substitution taken place or not ?

Find the code below :-

Code:

#!/bin/ksh
COUNT=0
#######  Create backup of the original file  ######
cp passwd passwd_old
#######  Read the csv file for unixid and project ######
while IFS=, read unix_id project_id
do
  UNIX_ID=${unix_id}
  PROJECT_ID=${project_id}
############ replace UNIX_ID with PROJECT_ID ##############
  print "converting $UNIX_ID to $X_ID .........................." >>log
  sed "s/$UNIX_ID/$PROJECT_ID/g" passwd >> passwd-new
  cp passwd-new passwd
  rm passwd-new
done < ids.csv

Now what I need is to detect whether a particular unix_id exists or better to confirm whether a particular substitution from unix_di to project_id taken place or not so that error logs and other logs can be generated efficiently

In this script you define lower case variables in the read statement and then define the same in upper case with the lower case's value. You could just write those in the read statement in upper case and save two redundant lines.

awk's sub() function can be assigned to a variable. It will be 1 on a succesful substitution, 0 on a fail.

If I got the logic right, you could just tell the script straight forward to replace the 1st field (UNIX_ID) with the second. It will always work so it would not help to know if the substitution worked or not, as the way you do it, it is forcing to overwrite it anyway, no matter if the UNIX_ID matches or not. It will always match as you wrote it. I am not sure if that is, what you wanted.

If your ids.csv looks like...

Code:

john,sales
martha,sales
ron,control
herbert,management

... your output would be always:

Code:

sales,sales
sales,sales
control,control
management,management

So either you want this and this can be done much easier with much less lines or there is something different logic behind it.

If there is really passwords involved in this, saving them in plain text to a file is really a security issue. You might at least want to use something like md5 to store passwords encrypted.