md5_b64#

One-shot MD5 digest, returned as a 22-character base64 string.

Synopsis#

use Digest::MD5 qw(md5_base64);
my $b64 = md5_base64($data);       # 22 chars, no padding

What you get back#

A 22-character string from the standard base64 alphabet A-Z a-z 0-9 + /. The tail is not padded to a multiple of 4 — the redundancy would encode nothing — so if an interop partner demands strict base64, append "==" yourself.

Base64 is about 30% shorter than hex and still fits on one line in a log or URL query parameter. The price is that it contains / and +, which are not safe in URL paths without further escaping.

Examples#

Compact digest for a cache key or tag:

use Digest::MD5 qw(md5_base64);
my $tag = md5_base64($payload);

## 22-character identifier, e.g. "rL0Y20zC+Fzt72VPzMSk2A"

Pad for strict base64 parsers:

my $padded = md5_base64($payload) . "==";

Store alongside the content in a manifest:

printf "%s  %s\n", md5_base64($bytes), $name;

Edge cases#

md5_base64() with no arguments returns 1B2M2Y8AsgTpgAmY7PhCfg.
Wide-character arguments croak; encode first.
The + and / characters require percent-encoding if the result appears in a URL path. Consider a URL-safe base64 transform (tr|+/|-_|) when serving digests in URLs.

Differences from upstream#

Fully compatible with upstream Digest::MD5 2.58.