New preferred name change report script (#23)

- This replaces preferred_name_logging.php
- Also updated readme.md

Author: pbailie

preferred_name_logging/pnc_compile.pl

@@ -0,0 +1,85 @@
+#!/usr/bin/env perl
+
+# Read Postgresql log and compile preferred name change report.
+
+# Invoke with -y or --yesterday to compile with yesterday's timestamps.
+# Useful if you run this script overnight starting after 12AM.
+
+# Author: Peter Bailie, RPI Research Computing
+# Date:   April 29, 2022
+
+use strict;
+use warnings;
+use autodie;
+use v5.30.0;
+use POSIX qw(strftime);
+
+# CONFIG -- denotes full path and file
+my $PSQL_LOG = "/var/log/postgresql/postgresql-12-main.log";
+my $PNC_LOG  = "preferred_name_change_report.log";
+
+# Main
+print STDERR "Root required.\n" and exit 1 if ($> != 0);
+
+my $epoch_offset = 0;
+$epoch_offset = -86400 if (scalar @ARGV > 0 && ($ARGV[0] eq "-y" || $ARGV[0] eq "--yesterday"));
+my $datestamp = strftime "%Y-%m-%d", gmtime(time + $epoch_offset);
+
+open my $psql_fh, "<:encoding(UTF-8)", $PSQL_LOG;
+open my $pnc_fh, ">>:encoding(UTF-8)", $PNC_LOG;
+
+my ($timestamp, $userid, $auth) = ("", "", "");
+my ($oldfn, $newfn, $oldln, $newln, $line1, $line2);
+while (<$psql_fh>) {
+    ($timestamp, $userid, $oldfn, $newfn, $oldln, $newln) = ($1, $2, $3, $4, $5, $6) if (/^${datestamp} (\d{2}:\d{2}:\d{2}\.\d{3} [A-Z]{3}).+DETAIL:  USER_ID: "(.+?)" (?:PREFERRED_FIRSTNAME OLD: "(.*?)" NEW: "(.*?)" )?(?:PREFERRED_LASTNAME OLD: "(.*?)" NEW: "(.*?)")?$/);
+    $auth = $1 if (/\/\* AUTH: "(.+)" \*\//);
+    # $auth is always on a different line than $timestamp, $userid.
+    # But all three having data will indicate we have collected pref name change logs.
+    if ($timestamp ne "" && $userid ne "" && $auth ne "") {
+        # $oldfn, $newfn, $oldln, $oldfn -- some may be undefined.
+        # This happens when either the firstname or lastname change wasn't recorded in PSQL logs (because no change occured).
+        # Undefined vars need to be defined to prevent 'concatenation by undefned var' warning.
+        foreach ($oldfn, $newfn, $oldln, $newln) {
+             $_ = "" if (!defined $_);
+        }
+
+        # If both old and new firstnames are blank, no change was logged.
+        if ($oldfn ne "" || $newfn ne "") {
+            ($oldfn, $newfn) = rpad(19, $oldfn, $newfn);
+            $line1 = "  OLD PREF FIRSTNAME: ${oldfn}";
+            $line2 = "  NEW PREF FIRSTNAME: ${newfn}";
+        } else {
+            ($line1, $line2) = ("", "");
+            ($line1, $line2) = rpad(41, $line1, $line2);
+        }
+
+        # If both old and new lastnames are blank, no change was logged.
+        if ($oldln ne "" || $newln ne "") {
+            ($oldln, $oldfn) = rpad(19, $oldln, $oldfn);
+            $line1 .= " OLD PREF LASTNAME: ${oldln}\n";
+            $line2 .= " NEW PREF LASTNAME: ${newln}\n";
+        } else {
+            $line1 .= "\n";
+            $line2 .= "\n";
+        }
+
+        ($userid) = rpad(9, $userid);
+        print $pnc_fh "${datestamp} ${timestamp}  USER: ${userid}  CHANGED BY: ${auth}\n";
+        print $pnc_fh $line1;
+        print $pnc_fh $line2;
+        ($timestamp, $userid, $auth) = ("", "", "");
+    }
+}
+
+close ($pnc_fh);
+close ($psql_fh);
+exit 0;
+
+# Right-pad string(s) with whitespaces.
+# expected parameters: (1) padding value, (2...n) strings to pad
+# return: list of padded strings
+sub rpad {
+    my $numpadding = shift;
+    $_ = sprintf("%-${numpadding}s", $_) foreach @_;
+    return @_;
+}