Find row containing string, then return that row and all following rows of text file with awk

Question

Apologies for any duplication, but most questions I've come across relate to getting a specific value from a field in a row, or using tail to get n tailing lines from a file, where n is known a priori. I'm looking to find a row where a value is matched, and then get all fields in that row AND all following rows. Details below.

I have data files returned from an online database that have a variable number of metadata header rows containing information about the query criteria used to search the database. After these header rows is a tidy dataframe. Example:

Query date: February 3, 2020, 1:34:57 PM
Database: <database name>
\n
Search criteria:
\n
Geographic bounding box coordinates: -130.00 20.00; -130.00 24.00; -120.00 24.00; -120.00 20.00
Sample type: rocks > sediments > dust
\n
SAMPLE ID,REFERENCE,LONGITUDE,LATITUDE,X,Y,Z,A
56,Author (YYYY) Title: Journal,-127.3,22,1.7,2.3,0,0.55
56,Author (YYYY) Title: Journal,-127.34,22.4,1.9,1.3,0.5

I have successfully found the row containing data field names using:

SID=$(awk -F, '{ if ($1 == "SAMPLE ID") print NR }' data.csv)

echo $SID returns 9, as expected

Now I want to take that row of field names and all of the following rows that contain the data and send them to a new file. In other words, I wish to parse the whole input file, and send the rows where NR >= $SID to a new file.

This is the code I've been using, but it instead just returns almost all of the data, except for a few rows. I can't figure out how to get the data I want, or why it's omitting the rows that it is.

awk -F, -v r=$SID '{ if (NR >= $r) print $0}' data.csv > output.csv

Here's my expected output:

SAMPLE ID,REFERENCE,LONGITUDE,LATITUDE,X,Y,Z,A
56,Author (YYYY) Title: Journal,-127.3,22,1.7,2.3,0,0.55
56,Author (YYYY) Title: Journal,-127.34,22.4,1.9,1.3,0.5

Any help would be great! If it wasn't clear, I'm totally new to awk! Meaning I'd also welcome links to any good introductory materials for learning.

Answer 1

In awk, $r would refer to the value of the r^th field, rather than the value of r itself. Your solution should work if you just replace $r by r :

awk -F, -v r=$SID '{ if (NR >= r) print $0}' data.csv

or (more idiomatically, using the default print action)

awk -F, -v r=$SID 'NR >= r' data.csv

---

However there's really no need to do it in two steps - either

awk -F, '$1 == "SAMPLE ID" {p=1} p' data.csv

or even (ignoring the CSV structure altogether)

awk '/^SAMPLE ID,/{p=1} p' data.csv

should work as well.