wp-includes/l10n/class-wp-translation-file-mo.php:188Exports translation contents as a string.
string public function export(): string { // Prefix the headers as the first key. $headers_string = ''; foreach ( $this->headers as $header => $value ) { $headers_string .= "{$header}: $value\n"; } $entries = array_merge( array( '' => $headers_string ), $this->entries ); $entry_count = count( $entries ); if ( false === $this->uint32 ) { $this->uint32 = 'V'; } $bytes_for_entries = $entry_count * 4 * 2; // Pair of 32bit ints per entry. $originals_addr = 28; /* header */ $translations_addr = $originals_addr + $bytes_for_entries; $hash_addr = $translations_addr + $bytes_for_entries; $entry_offsets = $hash_addr; $file_header = pack( $this->uint32 . '*', // Force cast to an integer as it can be a float on x86 systems. See https://core.trac.wordpress.org/ticket/60678. (int) self::MAGIC_MARKER, 0, /* rev */ $entry_count, $originals_addr, $translations_addr, 0, /* hash_length */ $hash_addr ); $o_entries = ''; $t_entries = ''; $o_addr = ''; $t_addr = ''; foreach ( array_keys( $entries ) as $original ) { $o_addr .= pack( $this->uint32 . '*', strlen( $original ), $entry_offsets ); $entry_offsets += strlen( $original ) + 1; $o_entries .= $original . "\0"; } foreach ( $entries as $translations ) { $t_addr .= pack( $this->uint32 . '*', strlen( $translations ), $entry_offsets ); $entry_offsets += strlen( $translations ) + 1; $t_entries .= $translations . "\0"; } return $file_header . $o_addr . $t_addr . $o_entries . $t_entries; }Introduced in 6.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/l10n/class-wp-translation-file-mo.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.