bash - Shell script to send email before password expires -

i need notify unix box users when there password going expires in number of days have used below script.

#!/bin/sh  rcvr1=test1@testvm.localdomain.com rcvr2=test2@testvm.localdomain.com  in babinlonston lonston babin  # convert current date seconds currentdate=`date +%s` # find expiration date of user userexp=`chage -l $i |grep 'password expires' | cut -d: -f2` # convert expiration date seconds passexp=`date -d “$userexp” +%s` # find remaining days expiry exp=`expr \( $passexp  – $currentdate \)` # convert remaining days sec days expday=`expr \( $exp / 86400 \)` if [ $expday -le 10 ]; echo “please necessary action”  | mailx -s “password $i expire in $expday day/s” $rcvr3,$rcvr2 fi done 

when ever run script below error.

[root@testvm ~]# sh script.sh date: operand `23,' try `date --help' more information. expr: syntax error expr: syntax error script.sh: line 20: [: -le: unary operator expected date: operand `+%s' try `date --help' more information. expr: syntax error expr: syntax error script.sh: line 20: [: -le: unary operator expected date: operand `+%s' try `date --help' more information. expr: syntax error expr: syntax error script.sh: line 20: [: -le: unary operator expected [root@testvm ~]# 

how can slove issue. instead of -le option need use.

don't run sh ./script - run in sh shell. run ./script

i've amended , made more "modern".

#!/bin/bash #  rcvr1=test1@testvm.localdomain.com rcvr2=test2@testvm.localdomain.com  in  babinlonston lonston babin    # convert current date seconds   currentdate=$(date +%s)    # find expiration date of user   userexp=$(chage -l $i | awk '/^password expires/ { print $nf }')    if [[ ! -z $userexp ]]        # convert expiration date seconds     passexp=$(date -d "$userexp" "+%s")      if [[ $passexp != "never" ]]           # find remaining days expiry       (( exp = passexp - currentdate))        # convert remaining days sec days       (( expday =  exp / 86400 ))        if ((expday < 10 ))               echo "please necessary action"  | mailx -s "password $i expire in $expday day/s" $rcvr3,$rcvr2       fi     fi   fi  done