Problem description & analysis

Below is text file txt.txt, where the second column contains quantities and the third column contains unit prices:

111111,34,24.5,Apple

 

222222,53,22.0,Mango

 

333333,,32.0,Orange

 

44444,22,12.6,

We are trying to handle this text file according to requirements below:

1. If there is any null field in the current row, output the words “Error in line# N: insufficient/invalid data”;

2. If the current row is empty, output the words “Line# N is empty”;

3. Simple calculations;

4. Append an empty row and a row of total sales, as shown below:

 

Transactions

================

Sold 34 Apple at £24.50

Line#2 is empty

Sold 53 Mango at £22.00

Line#4 is empty

Error in line#5: insufficient/invalid data

Line#6 is empty

Error in line#7: insufficient/invalid data

 

Total sales: £1999.00

Solution

Write the following script p1.dfx in esProc:

	A
1	=file("txt.txt").import@cw()
2	>total=0
3	>A1.run(if(~==[]:~="Line#"/#/"  is   empty",~.pos(null):~="Error in line#"/#/":     insufficient/invalid data";total+=~(2)*~(3),~="Sold    "/~(2)/""/~(4)/" at   £"/format("%-5.2f",~(3))))
4	="\nTransactions\n================"
5	="\nTotal sales:   £"/format("%-6.2f",total)
6	=file("result.txt").export(A4|A1|A5)

Explanation:

A1   @c option enables separating columns with the comma; @w option enables returning a sequence of sequences.

A2  Define cellset variable total and assign 0 to it as the initial value.

A3  Loop through A1’s sequence, during which if the current sequence is empty, output “Line# N is empty”; and if the current sequence contains any null members, output “Error in line# N: insufficient/invalid data”, otherwise calculate Quantity * Unit Price.

A4  The heading information to be output.

A5  The tail information, which is total sales, to be output.

A6  Export the concatenation of A4, A1, and A5 to result.txt.

Q & A Collection

https://stackoverflow.com/questions/59344061/read-empty-line-in-text-file