Say It Simply: Using Perl’s Built‑In ‘say’ to Cut Boilerplate and Avoid Newline Pitfalls

Problem: The Never‑Ending Print Boilerplate

When writing Perl scripts that generate human‑readable text, you almost always end up with the same pattern:

print "Hello, world!\n";

Every line you want to output ends with a literal \n or you have to remember to add a separate print "\n"; after a block of prints. This tiny repetition is harmless but it clutters code, makes refactoring tedious, and can lead to subtle bugs when you forget the newline or accidentally double‑print it.

Thesis: The Built‑In say Keyword Cuts the Boilerplate

Perl introduced the say keyword in version 5.10 as part of the feature pragma. It behaves like print but automatically appends a newline to the output. That means you can write:

use feature 'say';
say "Hello, world!";

or, on the command line, simply add -Mfeature=say:

perl -Mfeature=say -e 'say "Hello, world!";'

The result is the same as the longer print version, but the code is cleaner and less error‑prone.

Enabling say – Two Quick Paths

• At the top of a script: use feature 'say'; – this activates say for the entire file.
• Command‑line switch: -Mfeature=say – useful for one‑liners or when you cannot modify the source.

Both methods require a Perl interpreter that reports version 5.10 or newer. You can verify the version with:

perl -v

Look for a line that starts with This is perl followed by a number ≥ 5.10.

Practical Example: Refactor a Small Script

Suppose you have the following script that prints a CSV header and a few rows:

#!/usr/bin/perl
use strict;
use warnings;

print "Name,Age,Location\n";
print "Alice,30,New York\n";
print "Bob,25,Los Angeles\n";

Refactoring it with say is almost a one‑liner change. Replace the three print statements with say and add the pragma at the top:

#!/usr/bin/perl
use strict;
use warnings;
use feature 'say';

say "Name,Age,Location";
say "Alice,30,New York";
say "Bob,25,Los Angeles";

Running perl csv.pl yields the same output, but the code now reads naturally and the risk of missing a \n is eliminated.

When the Automatic Newline Can Bite You

Because say always appends a newline, it is ideal for plain text logs but problematic in contexts where you need fine‑grained control:

• Binary output – a newline is a byte and will corrupt the data stream.
• CSV or TSV files that require a single header line – using say for the header and print for rows keeps the file well‑formed.
• Multi‑line string building – if you concatenate strings manually, the extra newline can introduce unwanted blank lines.

In such cases, stick with print or use say only where the newline is acceptable.

Trade‑Offs and Compatibility

Aspect	Benefit	Risk / Limitation
Readability	Cleaner syntax for simple output	May hide the newline if you’re not careful
Portability	Works on all Perl 5.10+ installations	Pre‑5.10 Perl will throw a syntax error unless the feature is enabled or the code is updated
Binary safety	Not suitable for binary data streams	Using say in such contexts will corrupt the output
Performance	Negligible difference from print	None

Actionable Next Steps

1. Check your Perl version: perl -v. If it’s 5.10 or newer, you’re ready.
2. Try the one‑liner: perl -Mfeature=say -e 'say "Hello, world!";'. You should see a newline after the text.
3. Open an existing script and add use feature 'say'; at the top. Replace any print "...\n"; with say "..."; and run the script to confirm the output is unchanged.
4. When refactoring, keep an eye out for places where the automatic newline would be undesirable (e.g., CSV headers or binary dumps) and use print there.
5. Document the change in your codebase or README so future contributors know that say is in use and the version requirement.

By adopting say where appropriate, you reduce boilerplate, improve readability, and keep your scripts clean. Just remember the newline it adds and the version requirement, and you’ll avoid the most common pitfalls.