divinity76 · March 2, 2024 08:08 · Mar 2, 2024
diff --git a/merge_csv.php b/merge_csv.php
@@ -0,0 +1,113 @@
+<?php
+
+declare(strict_types=1);
+
+function fix_encoding(string $str): string
+{
+    //return $str;
+    return mb_convert_encoding($str, 'UTF-8', 'ISO-8859-1');
+}
+
+function parse_csv(string $csv, string $separator = ","): array
+{
+    $csv = strtr(
+        $csv,
+        [
+            "\xEF\xBB\xBF" => "", // remove UTF-8 byte order masks, if present
+            "\r\n" => "\n", // Windows CrLf=> Unix Lf
+            "\r" => "\n" // old-MacOS Cr => Unix Lf
+            // (both modern MacOS and Linux use Lf .. Windows is the only outlier)
+        ]
+    );
+    $lines = explode("\n", $csv);
+    $keys = str_getcsv(array_shift($lines), $separator);
+    $ret = array();
+    foreach ($lines as $lineno => $line) {
+        if (strlen($line) < 1) {
+            // ... probably malformed csv, but we'll allow it
+            continue;
+        }
+        $parsed = str_getcsv($line, $separator);
+        if (count($parsed) !== count($keys)) {
+            throw new \RuntimeException("error on csv line #{$lineno}: count mismatch:" . count($parsed) . ' !== ' . count($keys) . ": " . var_export([
+                'error' => 'count mismatch',
+                'keys' => $keys,
+                'parsed' => $parsed,
+                'line' => $line
+            ], true));
+        }
+        $ret[] = array_combine($keys, $parsed);
+    }
+    return $ret;
+}
+error_reporting(E_ALL);
+ini_set('display_errors', '1');
+set_error_handler(function ($errno, $errstr, $errfile, $errline) {
+    if (error_reporting() & $errno) {
+        throw new \ErrorException($errstr, 0, $errno, $errfile, $errline);
+    }
+});
+if ($argc !== 3) {
+    echo "Usage: php {$argv[0]} <file1.csv> <file2.csv>\n";
+    exit(1);
+}
+$file1 = $argv[1];
+$file2 = $argv[2];
+$raw1 = file_get_contents($file1);
+$raw2 = file_get_contents($file2);
+$raw1 = fix_encoding($raw1);
+$raw2 = fix_encoding($raw2);
+$csv1 = parse_csv($raw1);
+$csv2 = parse_csv($raw2);
+$merged = [];
+
+
+// Assuming both CSVs have the same headers and the merge is based on these headers.
+$headers = array_keys($csv1[0] + $csv2[0]); // Combine and get unique headers from both CSVs
+foreach ($csv1 as $index => $row) {
+    foreach ($headers as $header) {
+        // If the current header exists in both csv1 and csv2 rows
+        if (isset($csv2[$index][$header], $row[$header])) {
+            // If csv1's value is empty and csv2's value is not, take csv2's value
+            if (empty($row[$header]) && !empty($csv2[$index][$header])) {
+                $merged[$index][$header] = $csv2[$index][$header];
+            } else {
+                // Otherwise, use csv1's value (even if it's empty, since both are equal priority in this case)
+                $merged[$index][$header] = $row[$header];
+            }
+        } elseif (isset($row[$header])) {
+            // If the header exists only in csv1, take csv1's value
+            $merged[$index][$header] = $row[$header];
+        } elseif (isset($csv2[$index][$header])) {
+            // If the header exists only in csv2, take csv2's value
+            $merged[$index][$header] = $csv2[$index][$header];
+        }
+    }
+}
+
+// Handle the case where csv2 is longer than csv1
+if (count($csv2) > count($csv1)) {
+    for ($i = count($csv1); $i < count($csv2); $i++) {
+        foreach ($headers as $header) {
+            if (isset($csv2[$i][$header])) {
+                $merged[$i][$header] = $csv2[$i][$header];
+            }
+        }
+    }
+}
+
+function array_to_csv(array $data, string $delimiter = ",", string $enclosure = '"', string $escapeChar = "\\"): string {
+    $fh = fopen('php://temp', 'rw'); // Write to a temporary file
+    foreach ($data as $row) {
+        fputcsv($fh, $row, $delimiter, $enclosure, $escapeChar);
+    }
+    rewind($fh);
+    $csvString = stream_get_contents($fh);
+    fclose($fh);
+    return $csvString;
+}
+
+$mergedCsvString = array_to_csv($merged);
+// For demonstration, let's just print the merged CSV string
+echo mb_convert_encoding($mergedCsvString, 'ISO-8859-1', 'UTF-8');
+//echo $mergedCsvString;