テーマ： cross-platform
-
Line endings, encodings and paths: what breaks when a file moves between operating systems
CRLF versus LF, the inconsistent encoding defaults of Windows PowerShell 5.1 versus BOM-less UTF-8 in PowerShell 7, EBCDIC on IBM mainframe-family systems, and filesystems that disagree about case sensitivity and maximum path length: a checklist of what to verify before assuming a text file or a path behaves the same way on a different OS.
-
Checking an operating system's support lifecycle before automating against it
Automating patch, upgrade or compliance workflows against a host that has already passed end-of-life produces false confidence: no more security fixes are coming regardless of what the automation reports. This methodology lists where each major vendor publishes lifecycle dates and how to fold an EOL check into a pre-flight step.
-
Network configuration tools compared: nmcli, netplan, systemd-networkd and their Windows and macOS equivalents
Reading the current network configuration, setting a static address, and setting DNS servers — the same three tasks across NetworkManager's nmcli, Ubuntu's netplan, systemd-networkd, Windows PowerShell's networking cmdlets, and macOS's networksetup.
-
Privilege elevation compared: sudo, doas, UAC, runas and AIX RBAC — and how to detect it
sudo, doas, Windows UAC and macOS's admin group all answer the same question — is this session allowed to act as an administrator — with different mechanisms and different ways for a script to check the answer before attempting a privileged action.
-
Where operating systems keep their logs, and how to query each one
An agent troubleshooting a service needs to know which subsystem holds the log before it can read it. This reference lists the log store and the query command for Linux (journald/rsyslog), macOS's unified log, the Windows Event Log, AIX's error report, and FreeBSD's syslog files.
-
Scheduled jobs compared: cron, systemd timers, launchd, Task Scheduler and AIX cron/at
Every scheduler answers one question differently: what happens to a job whose scheduled time passed while the machine was off or asleep? Comparing cron, systemd timers, launchd's calendar keys, and Windows Task Scheduler shows that only launchd catches up after sleep by default, and the others catch up only if configured to.
-
Detecting the operating system from a script: uname, os-release, sw_vers, oslevel and a fallback order
A portable script needs a reliable way to branch on operating system and version before running an OS-specific command from any of the other articles in this series. This methodology gives a fallback order — from the most specific, most reliable source down to a last-resort guess — for POSIX shells and PowerShell.
-
Host firewalls compared: nftables, firewalld, ufw, Windows Defender Firewall, pf and ipfw
Listing rules, opening a port, making the change survive a reboot, and doing it without locking yourself out over SSH or RDP — the same four tasks across nftables, firewalld, ufw, Windows Defender Firewall, and the BSD pf and ipfw packet filters.
-
Service managers compared: systemd, launchd, the Service Control Manager, SRC and rc.d/OpenRC
Every general-purpose OS has something that starts, stops, supervises and boots services, but the commands and the persistence model differ. This reference maps start, stop, status, enable-at-boot and log access across systemd, launchd, Windows' Service Control Manager, AIX's SRC, and FreeBSD's rc.d and Alpine's OpenRC.
-
Clock sync compared: chrony, systemd-timesyncd, w32tm, macOS timed and AIX xntpd
A quick reference for checking whether a host's clock is actually synchronized, across the time daemons used by Linux, Windows, macOS and AIX — distinct from a deep dive on any single tool, since the check is the same shape everywhere: is a source configured, and is it currently in sync.
-
Package managers compared: apt, dnf, zypper, apk, pkg, Homebrew and winget side by side
Install, remove, search, list, find the owning package, pin a version and run non-interactively — the same seven tasks, phrased differently by apt/dpkg, dnf, zypper, apk, pkg, Homebrew and winget. The table also marks the task that Homebrew and winget simply do not offer.
-
File permission models compared: POSIX bits, POSIX ACLs, NFSv4/ZFS ACLs, NTFS and macOS ACLs
POSIX mode bits, POSIX ACLs, the NFSv4/ZFS ACL model, NTFS ACLs and macOS ACLs each express access control differently, and almost none of it survives copying a file from one system to another. This reference lists the read/write commands for each and what gets silently dropped in transit.
機械可読： JSON