UNIX for Dummies Questions & Answers

while read record
do
        primary_key_fields=`echo $record | cut -d "|" -f 1-${fields_to_compare}`
        data_part=`echo $record | cut -d "|" -f ${fields_to_skip}-`

        flag=`grep "${record}" ${yesterday_file_name}`
        if [ -z "${flag}" ]; then
                flag_tmp=`grep "${primary_key_fields}" $yesterday_file_name`
                yesterday_data_part=`echo ${flag_temp} | cut -d "|" -f ${fields_to_skip}-`
                if [ -z "${flag_tmp}" ] ; then
                        current_record="A|"${record}
                elif [ "${yesterday_data_part}" != "${data_part}" ] ; then
                        current_record="C|"${record}|sed "s/|I|/|U|/g"
                fi
                echo "${current_record}" >> $delta_file_name
        fi
done < $file_name

while read record
do
        primary_key_fields=`echo $record | cut -d "|" -f 1-${fields_to_compare}`
        flag=`fgrep "${primary_key_fields}" ${file_name}`
        if [ -z "${flag}" ]; then
                current_record="D|"`echo ${record| sed "s/|I|/|D|/g"`
                echo "${current_record}" >> $delta_file_name
        fi
done < ${yesterday_file_name}

awk '
    FILENAME=="file1" {
        Keys[$1 $2 $3]++
    }
    FILENAME=="file2" {
        if (Keys[$1 $2 $3] == 0) {
            print $0
        }
    }
' file1 file2 > newfile

#!/usr/bin/python
deltafile = open("delta.txt","a")
yfile = open("yester_file.txt") #open yesterday file
tfile = open("today_file.txt") #open today file

for i in xrange(0,2000000): #loop 2million records
        yesterline = yfile.readline().strip() #strip newline
        todayline = tfile.readline().strip()
        y_primary , y_2nd, y_3rd , y_4th = yesterline.split("|")
        t_primary, t_2nd, t_3rd, t_4th = todayline.split("|")
        if y_primary == t_primary:
                if y_4th != t_4th:         
                        print >> deltafile , "C|%s|%s|%s|%s" %( t_primary , t_2nd ,"U" , t_4th)
        else:
                print >> deltafile, "A|%s|%s|%s|%s" %( t_primary , t_2nd, t_3rd, t_4th )
                print >> deltafile, "D|%s|%s|%s|%s" %( y_primary , y_2nd, "D", y_4th)

deltafile.close() #close output file