---
name: endprotoent
signature: 'endprotoent'
since: 5.0
status: documented
categories: ["Network info"]
---

```{index} single: endprotoent; Perl built-in
```

*[Network info](../perlfunc-by-category)*

# endprotoent

Close the protocols database after iteration.

`endprotoent` is the terminator for the `getprotoent` / `setprotoent` /
`endprotoent` iteration triad that walks the system protocols database
(typically `/etc/protocols`). It releases whatever handle or state the
system C library kept open for the iteration. You call it once the
sequential walk is done; `getprotobyname` and `getprotobynumber` do
not need it — they open and close the database on each call.

Takes no arguments, returns nothing useful. This is a thin wrapper
over the system `endprotoent(3)` call.

## Synopsis

```perl
endprotoent
```

## What you get back

No meaningful return value. Calling it in list or scalar context
yields the empty list / undef-equivalent; nothing you'd want to check.
Its value is the side effect of closing the protocols database.

## Examples

Walk every protocol, then close the database:

```perl
setprotoent(1);                         # 1 = keep the file open between calls
while (my @p = getprotoent()) {
    my ($name, $aliases, $proto) = @p;
    print "$proto\t$name\n";
}
endprotoent();
```

Short-circuit mid-walk — `endprotoent` still closes cleanly:

```perl
setprotoent(0);
while (my @p = getprotoent()) {
    last if $p[0] eq 'tcp';
}
endprotoent();
```

Paired with a direct lookup, `endprotoent` is unnecessary — name and
number lookups manage their own state:

```perl
my @tcp = getprotobyname('tcp');        # no endprotoent needed
```

## Edge cases

- **Calling without a prior `setprotoent` / `getprotoent`**: harmless.
  The system call is idempotent; closing an already-closed database
  is a no-op on every supported platform.
- **No arguments accepted**: `endprotoent $x` is a syntax error —
  the built-in has arity zero.
- **Not reentrant**: the protocols database is a single global
  resource inside the C library. Two concurrent iterations in the
  same process step on each other's state. Use per-thread or
  per-subprocess walks if you need parallelism.
- **Platform quirks**: behaviour is whatever the host system's
  `endprotoent(3)` does. See `perlport` for the list
  of platforms where the network-database routines diverge or are
  absent entirely.
- **Stubbed on platforms without `/etc/protocols`**: on systems
  where the C library has no protocols database, the call is a
  no-op rather than an error.

## Differences from upstream

Fully compatible with upstream Perl 5.42.

## See also

- [`setprotoent`](setprotoent) — open the protocols database and
  optionally keep it open across `getprotoent` calls; pair with
  `endprotoent` to bracket a walk
- [`getprotoent`](getprotoent) — read the next entry during an
  iteration; drives the loop that `endprotoent` terminates
- [`getprotobyname`](getprotobyname) — single-shot lookup by protocol
  name; self-contained, no `endprotoent` needed
- [`getprotobynumber`](getprotobynumber) — single-shot lookup by
  protocol number; same independence from the iteration triad
- [`endservent`](endservent) — the analogous terminator for the
  services database; same idiom, different table
- [`endhostent`](endhostent) — the analogous terminator for the
  hosts database