Hey all,
I'll start by saying that I'm a complete beginner with perl, and while
I've done some shell scripting, my experience doing programming /
scripting work is pretty limited.
I have several hundred csv files containing a mix of comma separated
strings and numbers. Fortunately, they're all uniform, so it's easy
to tell what a given column/record/value represents, at least when I
look at the files in person. What I want to do is read all of these
files into an array, and take a given record from each line containing
a certain string -- an example of the type of data I have:
(number of hotdogs of a particular type I eat on each day)
,"hotdog type",monday,tuesday,wednesday,thursday,friday,saturday,sunday,total
,"red hot",0,0,0,1,0,0,0,1,
,"white hot",0,1,1,0,0,0,2,
,totals,0,1,2,0,0,0,3,
(I'm not actually that interested in hot dogs -- just using this as an
example). It's also worth noting that the header row appears in each
file.
Now, to take it a step further, each file contains information about a
different person's hotdog preferences, and the filenames use a
firstname.lastname.mm-dd-yy.csv. For each week, I have a file for
each person I am working with, and data was collected over a one year
period. Now that data collection has been completed, I need to find
the total number of white hots as well as the total number of red hots
consumed, and the total number of hot dogs consumed per person.
As someone with little to no experience programming, I think the steps
to do this are to:
* Concatenate all CSV files (hopefully using some function to make
each line identifiable to a particular subject in the study I'm
working on -- possibly by adding the filename as the last
column/record/value to each line? Maybe this should be done before
concatenation, but I'm not sure how.)
* Read the file into an array, using a comma to delimit fields in the array.
* Do some math -- add all of the "totals" columns together and output
that number to a text file, with a brief text description of what the
number represents.
* Sort the array by the identifying string ("red hot" or "white hot")
and break it into multiple arrays.
* Return the value for the "total" column in each array. Append those
values to the text file from two steps ago.
* Return to the original (unsplit) array, and sort by the participant
name (given in the original firstname.lastname . . . csv file.) Break
that array into an array for each participant.
* Return the total number of each type of hot dog the participant
consumed during the study period, as well as the total (combined)
number of hot dogs consumed by each participant and append it to the
aforementioned text file.
* Do a quick comparison to make sure the numbers match -- if the sum
of total hot dogs eaten by each participant exceeds the total number
of hotdogs consumed (in step 3), we have a problem. Exit and return a
minimally descriptive error. Cross check the other way too. If all
is well, exit cleanly.
Is this right? Any suggestions for how to build something like this?
I know I've probably made this out to be more complicated than it is,
but as someone with very little understanding of programming, I
figured it makes the most sense for me to separate out each step, and
chances are I will learn more about how to build this type of program
as a result. While I'm really grateful for any help, if I get code
snippets, I'm also interested in knowing how they work and why (very
brief descriptions or pointers to existing documentation would be more
than enough for me).
(Please forgive me for using hot dogs as an example. If you're a
vegetarian or an animal rights activist, you can substitute something
else -- no dogs, hot or otherwise, were harmed in this study :) ).
Thanks and best,
Graham
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