Stdlib: gethostname() — local hostname string (ext/standard/basic_functions.c parity) #3465

Category

stdlib

Problem

gethostname(): string|false returns the local host name from the OS (gethostname(2) on Linux). Logging, mail headers (mail() #3285 / #3493), and deployment probes call it alongside DNS helpers (#3258). The builtin is not registered in ext/standard/Module.php — invoking it is an undefined function under bin/vm.php (May 2026).

php-src reference

• php/php-src ext/standard/basic_functions.c — PHP_FUNCTION(gethostname)
• php/php-src ext/standard/basic_functions_arginfo.h — gethostname signature

Repro (failure today)

<?php
echo gethostname(), "\n";

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php -r "echo gethostname(), PHP_EOL;" 2>&1 | tail -3
php -r "echo gethostname(), PHP_EOL;"
'

Expected (Zend): non-empty hostname string (may be short name or FQDN).
Actual (this compiler): Call to undefined function gethostname().

Scope (this repo)

Done when

• gethostname() returns non-false string on Linux Docker harness
• function_exists('gethostname') is true
• Compliance PHPT green under VMTest
• script/capability-matrix.php row: gethostname VM=yes

Verification

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php -r "echo gethostname();"
./script/ci-fast.sh --filter VMTest -- tests matching gethostname
'