PartialStreamWriteUnchecked

warning native on by default

Group: Probable bugs

Detect fwrite whose result is ignored or checked only against false when the complete payload is then claimed sent via unconditional return true.

Example

<?php
function bad($socket, $payload) { fwrite($socket, $payload); return true; }

Reported:

• line 2: Verify that every payload byte was written.

Detection

• Report fwrite whose result is ignored or checked only against false when the complete payload is then claimed sent via unconditional return true.
• Resolve builtin calls and named arguments before checking the contract. Project-local callees are considered only when their bodies or immutable summaries establish the required facts. The default is enabled, with positive proof required.
• For flow-dependent conditions, require a reachable source-to-use path with no intervening invalidation. Unknown calls, ambiguous aliases, recursion or analysis-budget exhaustion cannot establish definite facts.

Exceptions (no report)

• Loops advancing by returned byte count, complete count checks, and best-effort writes without success claims are excluded.
• Unresolved targets, incomplete required facts, suppressed findings and PHP versions lacking the referenced API or language feature produce no report. User declarations shadowing builtin names are not builtin contracts.

Fix

No automatic fix: retry policy, nonblocking readiness and zero-byte writes need caller decisions.

PHP versions

Apply only on PHP versions supporting the referenced APIs and syntax (within PHP 5.3–8.5). Builtin behavior and argument contracts follow the configured PHP version. Extension-specific calls require resolved extension API symbols; do not treat same-named application functions as extension calls.

Options

None. Enable or disable this rule through normal rule configuration.

Configure

In custos.json:

{
  "rules": {
    "PartialStreamWriteUnchecked": {
      "enabled": false
    }
  }
}

Suppress

Before the statement or declaration (or the first statement of the file):

// @custos-ignore PartialStreamWriteUnchecked