# LINUX LS COMMAND CHEATSHEET
===============================

## BASIC USAGE
-------------
ls                      List files and directories in current directory
ls /path/to/directory   List contents of a specific directory
ls file1 file2          List information about specific files
ls ~                    List contents of your home directory
ls ..                   List contents of parent directory

## COMMON OPTIONS
---------------
-a, --all               Show all files including hidden files (starting with .)
-l                      Use long listing format (permissions, owner, size, date)
-h, --human-readable    Show file sizes in human-readable format (KB, MB, GB)
-t                      Sort by modification time, newest first
-S                      Sort by file size, largest first
-r, --reverse           Reverse the order of sorting
-d, --directory         List directory entries instead of contents
-F, --classify          Append indicator to entries (/ for directories, * for executables)
-i, --inode             Print the index number of each file
-R, --recursive         List subdirectories recursively

## USEFUL COMBINATIONS
--------------------
ls -la                  Long listing including hidden files
ls -lh                  Long listing with human-readable sizes
ls -ltr                 Long listing sorted by time (oldest first)
ls -lSh                 Long listing sorted by size (largest first) with human-readable sizes
ls -ld */               List only directories in current directory
ls -1                   List one file per line
ls -lR                  Recursively list all subdirectories with details
ls -la --time=atime     Show access time instead of modification time
ls -lZ                  Show security context (SELinux)

## FILTERING & SORTING
--------------------
ls *.txt                List all files with .txt extension
ls [abc]*               List files starting with 'a', 'b', or 'c'
ls -l | grep "^d"       List only directories (using grep)
ls -l | grep "^-"       List only regular files (using grep)
ls -l | sort -k 5 -n    Sort output by file size (numerical)
ls -l | sort -k 9       Sort output by filename

## FORMATTING OUTPUT
------------------
ls --color=auto         Colorize the output
ls --color=never        Disable colorized output
ls -l --time-style=long-iso    Show timestamps in ISO format
ls -l --time-style=full        Show full timestamps
ls --group-directories-first   List directories before files

## SCRIPT-FRIENDLY OPTIONS
------------------------
ls -1q                  One entry per line, non-printable chars as ?
ls -b                   Print C-style escapes for special characters
ls --quoting-style=shell    Quote filenames for use in shell commands

## PERFORMANCE TIPS
----------------
ls -U                   Do not sort (faster for large directories)
ls -f                   Do not sort, enable -a (fastest option)
ls --hide='*.tmp'       Hide certain files (like .tmp files)

## COMBINING WITH OTHER COMMANDS
-----------------------------
ls -la | grep "Jan"     Find files modified in January
ls -lS | head -10       Show 10 largest files
ls | wc -l              Count number of entries
find . -type f | wc -l  Count files recursively (alternative)

## ADVANCED USAGE
--------------
ls -lu                  Sort by last access time
ls -lc                  Sort by last status change time
ls --context            Display security context (SELinux)
ls -L                   Follow symbolic links
ls -Z                   Display SELinux security context

## ENVIRONMENT VARIABLES
---------------------
$LS_COLORS              Controls colorized output
$COLUMNS                Controls display width

## COMMON ALIASES
--------------
ll                      Usually aliased to 'ls -l'
la                      Usually aliased to 'ls -la'
l                       Often aliased to 'ls -CF'

TIP: Create your own aliases in ~/.bashrc or ~/.zshrc for frequently used options.