Appendix A: Command Reference

This appendix provides a quick reference to essential commands for macOS. Commands are organized by category for easy lookup. For detailed information on any command, use man command-name.

Legend

$ - Run as regular user
# - Requires sudo (administrator privileges)
[optional] - Optional parameter
<required> - Required parameter

File and Directory Operations

Command	Description	Example
`pwd`	Print working directory	`$ pwd`
`cd <dir>`	Change directory	`$ cd ~/Documents`
`cd -`	Return to previous directory	`$ cd -`
`ls`	List directory contents	`$ ls -la`
`ls -la`	Long format with hidden files	`$ ls -la ~/`
`ls -lah`	Human-readable sizes	`$ ls -lah`
`ls -lt`	Sort by modification time	`$ ls -lt`
`tree`	Directory tree (install via Homebrew)	`$ tree -L 2`

File Operations

Command	Description	Example
`cp <src> <dst>`	Copy file	`$ cp file.txt backup.txt`
`cp -r <src> <dst>`	Copy directory recursively	`$ cp -r dir1 dir2`
`cp -a <src> <dst>`	Archive mode (preserve attributes)	`$ cp -a /source /dest`
`mv <src> <dst>`	Move/rename file	`$ mv old.txt new.txt`
`rm <file>`	Remove file	`$ rm unwanted.txt`
`rm -r <dir>`	Remove directory recursively	`$ rm -r old_dir`
`rm -rf <dir>`	Force remove (dangerous!)	`$ rm -rf temp/`
`mkdir <dir>`	Create directory	`$ mkdir newdir`
`mkdir -p <path>`	Create nested directories	`$ mkdir -p a/b/c`
`rmdir <dir>`	Remove empty directory	`$ rmdir emptydir`
`touch <file>`	Create file or update timestamp	`$ touch newfile.txt`
`ln -s <target> <link>`	Create symbolic link	`$ ln -s /path/to/file link`
`ditto <src> <dst>`	Copy preserving macOS metadata	`$ ditto src dst`

File Information

Command	Description	Example
`file <file>`	Determine file type	`$ file document.pdf`
`stat <file>`	Display file status	`$ stat file.txt`
`du -sh <path>`	Disk usage summary	`$ du -sh ~/Downloads`
`du -h -d 1`	Disk usage one level deep	`$ du -h -d 1 ~/`
`wc -l <file>`	Count lines in file	`$ wc -l file.txt`
`mdls <file>`	View Spotlight metadata	`$ mdls photo.jpg`

Permissions

Command	Description	Example
`chmod <mode> <file>`	Change permissions	`$ chmod 755 script.sh`
`chmod +x <file>`	Make executable	`$ chmod +x run.sh`
`chmod -R <mode> <dir>`	Recursive permissions	`$ chmod -R 644 docs/`
`chown <user> <file>`	Change owner	`# chown admin file.txt`
`chown -R <user>:<group>`	Recursive ownership	`# chown -R www:www html/`
`chgrp <group> <file>`	Change group	`$ chgrp staff file.txt`
`ls -le`	List with ACLs	`$ ls -le`
`chmod +a <acl>`	Add ACL entry	`$ chmod +a "user:joe:allow read" file`

Text Processing

Viewing Files

Command	Description	Example
`cat <file>`	Display file contents	`$ cat file.txt`
`cat -n <file>`	Display with line numbers	`$ cat -n script.sh`
`head <file>`	First 10 lines	`$ head file.txt`
`head -n 20 <file>`	First N lines	`$ head -n 20 log.txt`
`tail <file>`	Last 10 lines	`$ tail file.txt`
`tail -n 50 <file>`	Last N lines	`$ tail -n 50 log.txt`
`tail -f <file>`	Follow file (live updates)	`$ tail -f /var/log/system.log`
`less <file>`	Page through file	`$ less largefile.txt`
`more <file>`	Simple pager	`$ more file.txt`

Searching

Command	Description	Example
`grep <pattern> <file>`	Search for pattern	`$ grep "error" log.txt`
`grep -i <pattern>`	Case-insensitive search	`$ grep -i "warning" file`
`grep -r <pattern> <dir>`	Recursive search	`$ grep -r "TODO" src/`
`grep -n <pattern>`	Show line numbers	`$ grep -n "func" code.py`
`grep -v <pattern>`	Invert match (exclude)	`$ grep -v "debug" log`
`grep -E <regex>`	Extended regex	`$ grep -E "err(or)?s?" log`
`grep -l <pattern>`	List matching files only	`$ grep -l "main" *.c`
`grep -c <pattern>`	Count matches	`$ grep -c "error" log.txt`
`mdfind <query>`	Spotlight search	`$ mdfind "project report"`
`mdfind -name <name>`	Search by filename	`$ mdfind -name "config.yaml"`

Text Manipulation

Command	Description	Example
`sort <file>`	Sort lines	`$ sort names.txt`
`sort -n <file>`	Numeric sort	`$ sort -n numbers.txt`
`sort -r <file>`	Reverse sort	`$ sort -r file.txt`
`sort -u <file>`	Sort and remove duplicates	`$ sort -u list.txt`
`uniq`	Remove adjacent duplicates	`$ sort file \| uniq`
`uniq -c`	Count occurrences	`$ sort file \| uniq -c`
`cut -d: -f1`	Extract field	`$ cut -d: -f1 /etc/passwd`
`cut -c1-10`	Extract characters	`$ cut -c1-10 file.txt`
`tr 'a-z' 'A-Z'`	Translate characters	`$ echo "hi" \| tr 'a-z' 'A-Z'`
`tr -d '\r'`	Delete characters	`$ tr -d '\r' < file.txt`
`sed 's/old/new/'`	Substitute first match	`$ sed 's/foo/bar/' file`
`sed 's/old/new/g'`	Substitute all matches	`$ sed 's/foo/bar/g' file`
`awk '{print $1}'`	Print first field	`$ awk '{print $1}' file`
`awk -F: '{print $1}'`	Custom delimiter	`$ awk -F: '{print $1}' passwd`

Comparison

Command	Description	Example
`diff <file1> <file2>`	Compare files	`$ diff old.txt new.txt`
`diff -u <f1> <f2>`	Unified diff format	`$ diff -u old new`
`diff -r <dir1> <dir2>`	Compare directories	`$ diff -r src1 src2`
`comm <f1> <f2>`	Compare sorted files	`$ comm list1 list2`
`cmp <f1> <f2>`	Byte-by-byte compare	`$ cmp file1 file2`

Finding Files

Command	Description	Example
`find <path> -name <pattern>`	Find by name	`$ find . -name "*.txt"`
`find <path> -type f`	Find files only	`$ find . -type f`
`find <path> -type d`	Find directories only	`$ find /var -type d`
`find <path> -mtime -7`	Modified in last 7 days	`$ find . -mtime -7`
`find <path> -size +100M`	Files larger than 100MB	`$ find . -size +100M`
`find <path> -empty`	Find empty files/dirs	`$ find . -empty`
`find <path> -exec cmd {} \;`	Execute command on results	`$ find . -name "*.log" -exec rm {} \;`
`locate <pattern>`	Search locate database	`$ locate nginx.conf`
`which <command>`	Show command path	`$ which python`
`whereis <command>`	Locate binary/man/source	`$ whereis ls`
`type <command>`	Describe command type	`$ type cd`

Archiving and Compression

Command	Description	Example
`tar -cvf <archive> <files>`	Create tar archive	`$ tar -cvf backup.tar dir/`
`tar -xvf <archive>`	Extract tar archive	`$ tar -xvf backup.tar`
`tar -czvf <archive> <files>`	Create gzipped tar	`$ tar -czvf backup.tar.gz dir/`
`tar -xzvf <archive>`	Extract gzipped tar	`$ tar -xzvf backup.tar.gz`
`tar -cjvf <archive> <files>`	Create bzip2 tar	`$ tar -cjvf backup.tar.bz2 dir/`
`tar -xjvf <archive>`	Extract bzip2 tar	`$ tar -xjvf backup.tar.bz2`
`tar -tvf <archive>`	List tar contents	`$ tar -tvf backup.tar`
`gzip <file>`	Compress with gzip	`$ gzip file.txt`
`gunzip <file.gz>`	Decompress gzip	`$ gunzip file.txt.gz`
`zip -r <archive> <dir>`	Create zip archive	`$ zip -r archive.zip dir/`
`unzip <archive>`	Extract zip archive	`$ unzip archive.zip`
`unzip -l <archive>`	List zip contents	`$ unzip -l archive.zip`

Process Management

Viewing Processes

Command	Description	Example
`ps aux`	List all processes	`$ ps aux`
`ps aux \| grep <name>`	Find specific process	`$ ps aux \| grep nginx`
`pgrep <name>`	Get PIDs by name	`$ pgrep -l Safari`
`top`	Interactive process viewer	`$ top`
`htop`	Enhanced top (install via Homebrew)	`$ htop`
`Activity Monitor`	GUI process manager	Open from Spotlight

Process Control

Command	Description	Example
`kill <PID>`	Terminate process	`$ kill 1234`
`kill -9 <PID>`	Force kill process	`$ kill -9 1234`
`killall <name>`	Kill by name	`$ killall Safari`
`pkill <pattern>`	Kill by pattern	`$ pkill -f "python script"`
`<command> &`	Run in background	`$ long_task &`
`jobs`	List background jobs	`$ jobs`
`fg`	Bring to foreground	`$ fg %1`
`bg`	Continue in background	`$ bg %1`
`nohup <cmd> &`	Run immune to hangups	`$ nohup ./script.sh &`
`Ctrl+Z`	Suspend current process
`Ctrl+C`	Interrupt current process

Resource Usage

Command	Description	Example
`vm_stat`	Virtual memory statistics	`$ vm_stat`
`iostat`	I/O statistics	`$ iostat`
`fs_usage`	Filesystem activity	`# fs_usage -f filesys`
`sample <PID> <secs>`	Sample process	`$ sample Safari 5`

System Information

Command	Description	Example
`uname -a`	System information	`$ uname -a`
`sw_vers`	macOS version	`$ sw_vers`
`system_profiler`	Detailed system info	`$ system_profiler SPHardwareDataType`
`hostname`	Show hostname	`$ hostname`
`whoami`	Current username	`$ whoami`
`id`	User ID and groups	`$ id`
`uptime`	System uptime	`$ uptime`
`date`	Current date/time	`$ date`
`cal`	Calendar	`$ cal`
`df -h`	Disk free space	`$ df -h`
`diskutil list`	List disks and partitions	`$ diskutil list`
`diskutil info <disk>`	Disk information	`$ diskutil info disk0`
`sysctl -a`	All kernel parameters	`$ sysctl -a`
`sysctl hw.memsize`	Total RAM	`$ sysctl hw.memsize`
`sysctl machdep.cpu`	CPU information	`$ sysctl machdep.cpu`
`ioreg -l`	IOKit registry	`$ ioreg -l`
`nvram -p`	NVRAM variables	`$ nvram -p`

Network Commands

Network Information

Command	Description	Example
`ifconfig`	Network interface config	`$ ifconfig`
`ifconfig en0`	Specific interface	`$ ifconfig en0`
`ipconfig getifaddr en0`	Get IP address	`$ ipconfig getifaddr en0`
`networksetup -listallnetworkservices`	List services	`$ networksetup -listallnetworkservices`
`networksetup -getinfo "Wi-Fi"`	Service info	`$ networksetup -getinfo "Wi-Fi"`
`scutil --dns`	DNS configuration	`$ scutil --dns`
`scutil --proxy`	Proxy configuration	`$ scutil --proxy`
`netstat -an`	Network connections	`$ netstat -an`
`netstat -rn`	Routing table	`$ netstat -rn`
`lsof -i`	Open network connections	`$ lsof -i`
`lsof -i :80`	Connections on port 80	`$ lsof -i :80`

Connectivity Testing

Command	Description	Example
`ping <host>`	Test connectivity	`$ ping apple.com`
`ping -c 5 <host>`	Send 5 pings	`$ ping -c 5 google.com`
`traceroute <host>`	Trace route to host	`$ traceroute apple.com`
`mtr <host>`	Combined ping/traceroute	`$ mtr google.com`
`curl <url>`	Transfer URL	`$ curl https://api.example.com`
`curl -I <url>`	Fetch headers only	`$ curl -I https://apple.com`
`curl -o <file> <url>`	Download to file	`$ curl -o file.zip https://url`
`wget <url>`	Download file (Homebrew)	`$ wget https://example.com/file`
`nc -zv <host> <port>`	Test port connectivity	`$ nc -zv google.com 443`
`nslookup <host>`	DNS lookup	`$ nslookup apple.com`
`dig <host>`	DNS lookup (detailed)	`$ dig apple.com`
`host <host>`	DNS lookup (simple)	`$ host apple.com`
`arp -a`	ARP table	`$ arp -a`

Wi-Fi

Command	Description	Example
`networksetup -setairportpower en0 on`	Turn Wi-Fi on	`$ networksetup -setairportpower en0 on`
`networksetup -setairportpower en0 off`	Turn Wi-Fi off	`$ networksetup -setairportpower en0 off`
`networksetup -getairportnetwork en0`	Current network	`$ networksetup -getairportnetwork en0`

Disk and Volume Management

Command	Description	Example
`diskutil list`	List all disks	`$ diskutil list`
`diskutil info <disk>`	Disk information	`$ diskutil info disk0`
`diskutil mount <vol>`	Mount volume	`$ diskutil mount disk2s1`
`diskutil unmount <vol>`	Unmount volume	`$ diskutil unmount disk2s1`
`diskutil eject <disk>`	Eject disk	`$ diskutil eject disk2`
`diskutil verifyVolume <vol>`	Verify filesystem	`# diskutil verifyVolume /`
`diskutil repairVolume <vol>`	Repair filesystem	`# diskutil repairVolume disk1`
`diskutil apfs list`	List APFS volumes	`$ diskutil apfs list`
`hdiutil attach <dmg>`	Mount disk image	`$ hdiutil attach image.dmg`
`hdiutil detach <vol>`	Detach disk image	`$ hdiutil detach /Volumes/Image`
`hdiutil create`	Create disk image	`$ hdiutil create -size 1g -fs APFS -volname "MyDisk" disk.dmg`
`tmutil`	Time Machine utility	`$ tmutil listbackups`

User Management

Command	Description	Example
`whoami`	Current user	`$ whoami`
`id`	User/group IDs	`$ id`
`groups`	Group memberships	`$ groups`
`dscl . -list /Users`	List all users	`$ dscl . -list /Users`
`dscl . -list /Groups`	List all groups	`$ dscl . -list /Groups`
`dscl . -read /Users/<user>`	User details	`$ dscl . -read /Users/admin`
`dscacheutil -q user`	Query user cache	`$ dscacheutil -q user`
`sysadminctl -addUser`	Add user	`# sysadminctl -addUser joe -password pass`
`sysadminctl -deleteUser`	Delete user	`# sysadminctl -deleteUser joe`
`sudo -s`	Root shell	`$ sudo -s`
`su - <user>`	Switch user	`$ su - otheruser`

Service and Process Management

launchctl

Command	Description	Example
`launchctl list`	List loaded services	`$ launchctl list`
`launchctl list \| grep <name>`	Find service	`$ launchctl list \| grep apache`
`launchctl load <plist>`	Load service (legacy)	`$ launchctl load ~/Library/LaunchAgents/job.plist`
`launchctl unload <plist>`	Unload service (legacy)	`$ launchctl unload ~/Library/LaunchAgents/job.plist`
`launchctl bootstrap gui/<uid> <plist>`	Bootstrap service	`$ launchctl bootstrap gui/501 job.plist`
`launchctl bootout gui/<uid> <plist>`	Remove service	`$ launchctl bootout gui/501 job.plist`
`launchctl kickstart`	Start service	`$ launchctl kickstart gui/501/com.example.agent`
`launchctl kill <sig> <service>`	Send signal	`# launchctl kill SIGTERM system/com.example.daemon`
`launchctl print system`	Print system domain	`$ launchctl print system`
`launchctl print gui/501`	Print user domain	`$ launchctl print gui/501`

Homebrew Services

Command	Description	Example
`brew services list`	List services	`$ brew services list`
`brew services start <name>`	Start service	`$ brew services start postgresql`
`brew services stop <name>`	Stop service	`$ brew services stop postgresql`
`brew services restart <name>`	Restart service	`$ brew services restart nginx`
`brew services run <name>`	Run once (no restart)	`$ brew services run redis`

Package Management (Homebrew)

Command	Description	Example
`brew install <pkg>`	Install package	`$ brew install wget`
`brew uninstall <pkg>`	Uninstall package	`$ brew uninstall wget`
`brew upgrade`	Upgrade all packages	`$ brew upgrade`
`brew upgrade <pkg>`	Upgrade specific package	`$ brew upgrade node`
`brew update`	Update Homebrew	`$ brew update`
`brew search <term>`	Search packages	`$ brew search python`
`brew info <pkg>`	Package information	`$ brew info python`
`brew list`	List installed packages	`$ brew list`
`brew list --cask`	List installed casks	`$ brew list --cask`
`brew outdated`	Show outdated packages	`$ brew outdated`
`brew cleanup`	Remove old versions	`$ brew cleanup`
`brew doctor`	Diagnose issues	`$ brew doctor`
`brew deps <pkg>`	Show dependencies	`$ brew deps node`
`brew uses --installed <pkg>`	What uses this package	`$ brew uses --installed openssl`
`brew install --cask <app>`	Install GUI app	`$ brew install --cask firefox`

macOS-Specific Commands

Clipboard

Command	Description	Example
`pbcopy`	Copy to clipboard	`$ cat file.txt \| pbcopy`
`pbpaste`	Paste from clipboard	`$ pbpaste > output.txt`
`pbcopy < file.txt`	Copy file contents	`$ pbcopy < ~/.ssh/id_rsa.pub`

Launching and Opening

Command	Description	Example
`open <file>`	Open with default app	`$ open document.pdf`
`open -a <app> <file>`	Open with specific app	`$ open -a "Visual Studio Code" .`
`open .`	Open current dir in Finder	`$ open .`
`open <url>`	Open URL in browser	`$ open https://apple.com`
`open -R <file>`	Reveal in Finder	`$ open -R file.txt`

System

Command	Description	Example
`say <text>`	Text-to-speech	`$ say "Hello world"`
`screencapture`	Take screenshot	`$ screencapture screen.png`
`screencapture -c`	Screenshot to clipboard	`$ screencapture -c`
`pmset -g`	Power management status	`$ pmset -g`
`pmset -g batt`	Battery status	`$ pmset -g batt`
`caffeinate`	Prevent sleep	`$ caffeinate -t 3600`
`softwareupdate -l`	List software updates	`$ softwareupdate -l`
`softwareupdate -ia`	Install all updates	`# softwareupdate -ia`
`defaults read`	Read preferences	`$ defaults read com.apple.finder`
`defaults write`	Write preferences	`$ defaults write com.apple.finder ShowHiddenFiles -bool true`
`osascript -e`	Run AppleScript	`$ osascript -e 'display notification "Done"'`

Spotlight

Command	Description	Example
`mdfind <query>`	Spotlight search	`$ mdfind "meeting notes"`
`mdfind -name <name>`	Search by name	`$ mdfind -name "config.yaml"`
`mdfind -onlyin <dir> <query>`	Search in directory	`$ mdfind -onlyin ~/Documents "report"`
`mdls <file>`	File metadata	`$ mdls photo.jpg`
`mdutil -s /`	Spotlight status	`$ mdutil -s /`
`mdutil -E /`	Rebuild Spotlight index	`# mdutil -E /`

Logging and Debugging

Command	Description	Example
`log show`	View unified log	`$ log show --last 1h`
`log show --predicate`	Filter logs	`$ log show --predicate 'process == "Safari"'`
`log stream`	Real-time log stream	`$ log stream --level debug`
`console`	Open Console.app	`$ open -a Console`
`syslog`	Legacy system log (deprecated)	`$ syslog`
`dmesg`	Kernel messages	`$ dmesg`
`system_profiler SPLogsDataType`	System logs info	`$ system_profiler SPLogsDataType`

Security Commands

Command	Description	Example
`csrutil status`	SIP status	`$ csrutil status`
`spctl --status`	Gatekeeper status	`$ spctl --status`
`spctl -a -v <app>`	Verify app signature	`$ spctl -a -v /Applications/Safari.app`
`codesign -dv <app>`	Code signature details	`$ codesign -dv /Applications/Safari.app`
`codesign -s <identity> <file>`	Sign code	`$ codesign -s "Developer ID" myapp`
`security list-keychains`	List keychains	`$ security list-keychains`
`security find-identity -v`	List signing identities	`$ security find-identity -v`
`security find-generic-password`	Find password	`$ security find-generic-password -s "service"`
`fdesetup status`	FileVault status	`$ fdesetup status`
`sudo spctl --master-disable`	Disable Gatekeeper	`# spctl --master-disable`

Remote Access

Command	Description	Example
`ssh <user>@<host>`	SSH connection	`$ ssh admin@server.local`
`ssh -i <key> <user>@<host>`	SSH with key	`$ ssh -i ~/.ssh/mykey user@host`
`ssh -L <local>:<remote>`	SSH tunnel	`$ ssh -L 8080:localhost:80 user@host`
`scp <src> <user>@<host>:<dst>`	Secure copy	`$ scp file.txt user@host:/path/`
`scp -r <dir> <user>@<host>:<dst>`	Recursive copy	`$ scp -r dir/ user@host:/path/`
`rsync -avz <src> <dst>`	Sync files	`$ rsync -avz dir/ user@host:/path/`
`sftp <user>@<host>`	SFTP session	`$ sftp admin@server.local`

Shell Built-ins and History

Command	Description	Example
`history`	Show command history	`$ history`
`history \| grep <term>`	Search history	`$ history \| grep git`
`!!`	Repeat last command	`$ !!`
`!<n>`	Run command N from history	`$ !42`
`!<string>`	Run last command starting with	`$ !git`
`Ctrl+R`	Reverse search history
`alias`	Show aliases	`$ alias`
`alias <name>=<cmd>`	Create alias	`$ alias ll='ls -la'`
`unalias <name>`	Remove alias	`$ unalias ll`
`export <var>=<val>`	Set environment variable	`$ export PATH="/usr/local/bin:$PATH"`
`env`	Show environment	`$ env`
`printenv`	Print environment variables	`$ printenv`
`echo $<var>`	Print variable	`$ echo $HOME`

Getting Help

Command	Description	Example
`man <command>`	Manual page	`$ man ls`
`man -k <term>`	Search manual pages	`$ man -k network`
`apropos <term>`	Same as man -k	`$ apropos copy`
`<command> --help`	Command help	`$ git --help`
`<command> -h`	Short help	`$ grep -h`
`whatis <command>`	One-line description	`$ whatis curl`
`info <command>`	GNU info pages	`$ info bash`

Quick Reference: Keyboard Shortcuts in Commands

Shortcut	Action
`Ctrl+C`	Cancel/interrupt
`Ctrl+D`	EOF/logout
`Ctrl+Z`	Suspend process
`Ctrl+L`	Clear screen
`Ctrl+A`	Beginning of line
`Ctrl+E`	End of line
`Ctrl+U`	Clear line before cursor
`Ctrl+K`	Clear line after cursor
`Ctrl+W`	Delete word before cursor
`Ctrl+R`	Reverse search history
`Tab`	Auto-complete
`Tab Tab`	Show completions