script to loop through and combine two text files - shell

Question

I have two .csv files which I am trying to 'multiply' out via a script. The first file is person information and looks basically like this:
First Name, Last Name, Email, Phone
Sally,Davis,sdavis#nobody.com,555-555-5555
Tom,Smith,tsmith#nobody.com,555-555-1212
The second file is account numbers and looks like this:
AccountID
1001
1002
Basically I want to get every name with every account Id. So if I had 10 names in the first file and 10 account IDs in the second file, I should end up with 100 rows in the resulting file and have it look like this:
First Name, Last Name, Email, Phone, AccountID
Sally,Davis,sdavis#nobody.com,555-555-5555, 1001
Tom,Smith,tsmith#nobody.com,555-555-1212, 1001
Sally,Davis,sdavis#nobody.com,555-555-5555, 1002
Tom,Smith,tsmith#nobody.com,555-555-1212, 1002
Any help would be greatly appreciated

Answer 1

You could simply write a for loop for each value to be repeated by it's id count and append the description, but just in the reverse order.
Has that not worked or have you not tried that?

Answer 2

If python works for you, here's a script which does that:
def main():
f1 = open("accounts.txt", "r")
f1_total_lines = sum(1 for line in open('accounts.txt'))
f2_total_lines = sum(1 for line in open('info.txt'))
f1_line_counter = 1;
f2_line_counter = 1;
f3 = open("result.txt", "w")
f3.write('First Name, Last Name, Email, Phone, AccountID\n')
for line_account in f1.readlines():
f2 = open("info.txt", "r")
for line_info in f2.readlines():
parsed_line_account = line_account
parsed_line_info = line_info.rstrip() # we have to trim the newline character from every line from the 'info' file
if f2_line_counter == f2_total_lines: # ...for every but the last line in the file (because it doesn't have a newline character)
parsed_line_info = line_info
f3.write(parsed_line_info + ',' + parsed_line_account)
if f1_line_counter == f1_total_lines:
f3.write('\n')
f2_line_counter = f2_line_counter + 1
f1_line_counter = f1_line_counter + 1
f2_line_counter = 1 # reset the line counter to the first line
f1.close()
f2.close()
f3.close()
if __name__ == '__main__':
main()
And the files I used are as follows:
info.txt:
Sally,Davis,sdavis#nobody.com,555-555-555
Tom,Smith,tsmith#nobody.com,555-555-1212
John,Doe,jdoe#nobody.com,555-555-3333
accounts.txt:
1001
1002
1003

Answer 3

If You Intended to Duplicate Account_ID
If you intended to add each Account_ID to every record in your information file then a short awk solution will do, e.g.
$ awk -F, '
FNR==NR{a[i++]=$0}
FNR!=NR{b[j++]=$0}
END{print a[0] ", " b[0]
for (k=1; k<i; k++)
for (m=1; m<i; m++)
print a[m] ", " b[k]}
' info id
First Name, Last Name, Email, Phone, AccountID
Sally,Davis,sdavis#nobody.com,555-555-5555, 1001
Tom,Smith,tsmith#nobody.com,555-555-1212, 1001
Sally,Davis,sdavis#nobody.com,555-555-5555, 1002
Tom,Smith,tsmith#nobody.com,555-555-1212, 1002
Above the lines in the first file (when the file-record-number equals the record-number, e.g. FNR==NR) are stored in array a, the lines from the second file (when FNR!=NR) are stored in array b and then they combined and output in the END rule in the desired order.
Without Duplicating Account_ID
Since Account_ID is usually a unique bit of information, if you did not intended to duplicate every ID at the end of each record, then there is no need to loop. The paste command does that for you. In your case with your information file as info and you account ID file as id, it is as simple as:
$ paste -d, info id
First Name, Last Name, Email, Phone,AccountID
Sally,Davis,sdavis#nobody.com,555-555-5555,1001
Tom,Smith,tsmith#nobody.com,555-555-1212,1002
(note: the -d, option just sets the delimiter to a comma)
Seems a lot easier that trying to reinvent the wheel.

Answer 4

Can be easily done with arrays
OLD=$IFS; IFS=$'\n'
ar1=( $(cat file1) )
ar2=( $(cat file2) )
IFS=$OLD
ind=${!ar1[#]}
for i in $ind; { echo "${ar1[$i]}, ${ar2[$i]}"; }