Backup user accounts from a linux system (non-system users)

backup-usrinfo.sh

#!/bin/bash -e
# Backup user accounts from a linux system (non-system users)

UGIDLIMIT=1000
MAXLIMIT=29999

# Create a directory to backup
MIGDIR="/tmp/backuinfo"
mkdir -p $MIGDIR && chmod 750 $MIGDIR

# Get password
awk -v LIMIT=$UGIDLIMIT -F: '($3>=LIMIT) && ($3!=$MAXLIMIT)' /etc/passwd > $MIGDIR/passwd.mig

# Get group
awk -v LIMIT=$UGIDLIMIT -F: '($3>=LIMIT) && ($3!=$MAXLIMIT)' /etc/group > $MIGDIR/group.mig
cp /etc/gshadow $MIGDIR/gshadow.mig

# Get password
awk -v LIMIT=$UGIDLIMIT -F: '($3>=LIMIT) && ($3!=$MAXLIMIT) {print $1}' /etc/passwd | tee - | egrep -f - /etc/shadow > $MIGDIR/shadow.mig

echo "Backed up user information to '$MIGDIR'. Please save it at a safe place."
exit 0