[Performance] MasterFingerprint::readUidForPid() reads whole /proc/{pid}/status — bounded fread + strpos would reduce the read

[s2x]

Description

Found during the #567 cycle. MasterFingerprint::readUidForPid() (src/MasterFingerprint.php:114-135) reads the entire /proc/{pid}/status file and runs a multiline regex (preg_match('/^Uid:\s+(\d+)/m', ...)). The Uid: field is near the head of the file, so a bounded fread() of the first ~256 bytes plus strpos() avoids the full read and PCRE. UID cannot be read from /proc/{pid}/stat, so the file itself cannot be avoided — only the read size.

Reachable from ProcessInspector::readLinuxProcessSnapshot() (src/ProcessInspector.php:519) and MasterFingerprint::capture().

Where

• src/MasterFingerprint.php:114-135

Suggested fix

Bounded fread() of the head of /proc/{pid}/status + strpos()/parse, replacing the full file_get_contents() + /m regex.