Understanding the /etc/hosts file in LinuxBase 16Convert a base 16 hexadecimal string to decimal in LinuxCommand substitutionCommand substitutionCPUHigh CPU on LinuxDisk QuotaDisk QuotadisplayUnderstanding the $DISPLAY variableEditor$EDITOR variable (default editor)epoch timeUnderstanding epoch timeForeground / BackgroundRunning jobs in the foreground and background in LinuxFundamentalsDBUSUnderstanding init, sysvinit, upstart, and systemdHierarchy StandardsUnderstanding the Hierarchy StandardsLogsUnderstanding syslog (system log) daemonMemory / RAMAnalyzing swap memoryNetworkingSubnet Mask (cidr) cheat sheetTest connectivity to another computer in LinuxPAMPAM (Pluggable Authentication Modules) PATH$LD_LIBRARY_PATH variable$PATH variablePath$LD_LIBRARY_PATH variable$PATH variablePermissionsUnderstanding standard permissionsUnderstanding the SUID, SGID and Sticky Bit permissionsRedirectionRedirection (stdout stderr)Rescue modeRescue modeRunlevelsUnderstanding runlevelsScreen ReaderHow to download and install Orca screen reader in LinuxStoragekibibyes (KiB) vs kilobyes and mebibytes (MiB) vs megabytes (MB)sysfssysfs (System File System)SystemdSystemd service filesTTYSwitch between TTY consolesVariablesUnderstanding environment variables