GNU/Linux

Quick Reference / Last modified: July 31, 2013

The following options may be given without explanation:
-h -? --help --usage   show help info;
-V --version show program version;
-v --verbose produce verbose output;

Note!

Some programs (utilities) described (mentioned, referenced) here may be not installed or missing from your distribution.

Some shortcuts:
~the subject of discussion
alphanumalphanumeric
argargument
authauthentication
autoautomatically
charcharacter
chkcheck
cmdcommand
connconnection
devdevice
dirdirectory
dst,destdestination
envenvironment
exprexpression
extextension | external
fsfilesystem
fwdforward
grpgroup
HW,hwhardware
initinitialization
msgmessage
miscmiscellaneous
paramparameter
passwdpassword
permpermission
pktpacket
prevprevious
recrecord
regexpregular expression
reqrequest
secsecond
specspecified, specification
srcsource
statsstatistics
stdstandard
stderrstandard error output
stdinstandard input
stdoutstandard output
symlinksymbolic link
Some abbreviations:
ACLAccess Control List
ALSAAdvanced Linux Sound Architecture
APAccess Point
BERBasic Encoding Rules (certificate format)
BIOSBasic Input / Output System
BREbasic regular expression
CIDRClassless Internet Domain Routing
CMOSnon-volatile RAM
CRcarriage return
DACDiscretionary Access Control (old Unix security model)
DERDistinguished Encoding Rules (certificate format)
DMIDirect Media Interface (link/bus for Intel chipsets)
EDACError Detection And Correction
EFIExtensible Firmware Interface (see "Boot procedure")
EOFend of file
EOLend of line
EREextended regular expression
FIBForwarding Information Base
FQDNFully Qualified Domain Name
GPTGUID Partition Table (see "Boot procedure")
GUIGraphical User Interface
ISPInternet service provider
LADSPALinux Audio Developers Simple Plugin API
LFline feed, newline
LIRLocal Internet Registry (usually ISP)
MACMandatory Access Control (security model)
MACMedia Access Control
MBRMaster Boot Record
MTAMail Transfer Agent (sendmail, postfix)
MTUMaximum Transmission Unit
NATNetwork Address Translation
NICNetwork Interface Card
NL,nlnewline
NVRAM non-volatile RAM (aka CMOS)
PCREPERL-compatible regular expression
PEMPrivacy Enhanced Mail Base64 encoded DER certificate
PKIPublic Key Infrastructure
POSTPower-On Self-Tests
RIBRouting Information Base
RIRRegional Internet Registry
SASLSimple Authentication and Security Layer
SSLSecure Socket Layers
TLBTranslation Lookaside Buffer
TLSTransport Layer Security
UEFIUnified Extensible Firmware Interface (see "Boot procedure")