Inspect text and count records

Inspect text and count records — guided practice

Distinguish lines including a header from data records.

Create an empty shell-lab folder. Inside it create input and output folders. Put registrations.tsv in input with these tab-separated rows and a final newline: session<TAB>status; art<TAB>confirmed; code<TAB>confirmed; art<TAB>waiting; code<TAB>confirmed; music<TAB>confirmed. Start the terminal in shell-lab. Bash required; no sudo, remote systems or deletion commands. Return to shell-lab before starting. Use the supplied file unchanged.

1. 1. Read the file

   Print the complete file.

   cat input/registrations.tsv

   You should see: One header and five data rows appear.

   Knowing the structure prevents a misleading count.

2. 2. Count all lines

   Run the line count.

   wc -l < input/registrations.tsv

   You should see: It reports 6 because the header is also a line.

   A tool measures its defined unit, not your intended business unit.

3. 3. Exclude the header

   Print from line 2 onward and count.

   tail -n +2 input/registrations.tsv | wc -l

   You should see: The count is 5.

   The first line is field names, not a registration.

4. 4. Compare

   Save a note: physical lines=6, registration rows=5.

   You should see: The difference is exactly one header.

   Explicit units make a summary understandable.