oshi.driver.unix.aix.Who Maven / Gradle / Ivy
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/*
* Copyright 2020-2023 The OSHI Project Contributors
* SPDX-License-Identifier: MIT
*/
package oshi.driver.unix.aix;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import oshi.annotation.concurrent.ThreadSafe;
import oshi.util.ExecutingCommand;
/**
* Utility to query logged in users.
*/
@ThreadSafe
public final class Who {
// sample format:
// system boot 2020-06-16 09:12
private static final Pattern BOOT_FORMAT_AIX = Pattern.compile("\\D+(\\d{4}-\\d{2}-\\d{2})\\s+(\\d{2}:\\d{2}).*");
private static final DateTimeFormatter BOOT_DATE_FORMAT_AIX = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm",
Locale.ROOT);
private Who() {
}
/**
* Query {@code who -b} to get boot time
*
* @return Boot time in milliseconds since the epoch
*/
public static long queryBootTime() {
String s = ExecutingCommand.getFirstAnswer("who -b");
if (s.isEmpty()) {
s = ExecutingCommand.getFirstAnswer("/usr/bin/who -b");
}
Matcher m = BOOT_FORMAT_AIX.matcher(s);
if (m.matches()) {
try {
return LocalDateTime.parse(m.group(1) + " " + m.group(2), BOOT_DATE_FORMAT_AIX)
.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli();
} catch (DateTimeParseException | NullPointerException e) {
// Shouldn't happen with regex matching
}
}
return 0L;
}
}