Class PosixCommands

java.lang.Object

org.jline.builtins.PosixCommands

public class PosixCommands
extends Object

POSIX-like command implementations for JLine applications.

This class provides implementations of common POSIX commands that can be used in JLine-based applications. The commands are designed to be reusable and independent of any specific command framework.

Available commands include:

• cat - concatenate and print files
• echo - display text
• grep - search text patterns
• ls - list directory contents
• pwd - print working directory
• head - display first lines of files
• tail - display last lines of files
• wc - word, line, character, and byte count
• date - display or set date
• sleep - suspend execution
• sort - sort lines of text
• clear - clear terminal screen

See Also:

• POSIX Utilities

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	PosixCommands.CommandExecutor	Interface for executing shell commands in watch.
static class	PosixCommands.Context	Context for command execution, providing I/O streams and current directory.
static class	PosixCommands.SortComparator	Comparator for sorting strings with various options.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DEFAULT_GREP_COLORS
static final String	DEFAULT_LS_COLORS

Constructor Summary

Constructors

Constructor	Description
PosixCommands()

Method Summary

Modifier and Type	Method	Description
static String	applyStyle(String text, Map<String,String> colors, String... types)	Apply style to text using color map.
static void	applyStyle(org.jline.utils.AttributedStringBuilder sb, Map<String,String> colors, String... types)	Apply style to AttributedStringBuilder using color map.
static void	cat(PosixCommands.Context context, String[] argv)	Cat command - concatenate and print files.
static void	cd(PosixCommands.Context context, String[] argv)	Change directory command.
static void	cd(PosixCommands.Context context, String[] argv, Consumer<Path> directoryChanger)	Change directory command with directory changer.
static void	clear(PosixCommands.Context context, String[] argv)	Clear command - clear terminal screen.
static void	date(PosixCommands.Context context, String[] argv)	Date command - display current date and time.
static void	echo(PosixCommands.Context context, Object[] argv)	Echo command - display text (Object array version for compatibility).
static void	echo(PosixCommands.Context context, String[] argv)	Echo command - display text.
protected static String	get(PosixCommands.Context context, String name)
static Map<String,String>	getColorMap(String colorString)	Get color map from color string.
static Map<String,String>	getColorMap(Function<String,Object> variables, String name, String def)
static Map<String,String>	getColorMap(PosixCommands.Context session, String name, String def)
static Map<String,String>	getLsColorMap(String colorString)	Get color map for ls command.
static Map<String,String>	getLsColorMap(PosixCommands.Context session)
static void	grep(PosixCommands.Context context, String[] argv)	Grep command - search text patterns.
static void	head(PosixCommands.Context context, String[] argv)	Head command - display first lines of files.
static void	less(PosixCommands.Context context, String[] argv)	Pager command - view files with less-like interface.
static void	ls(PosixCommands.Context context, String[] argv)	List directory contents command.
static void	nano(PosixCommands.Context context, String[] argv)	Text editor command - edit files with nano-like interface.
protected static Options	parseOptions(PosixCommands.Context context, String[] usage, Object[] argv)
static void	pwd(PosixCommands.Context context, String[] argv)	Print working directory command.
static void	sleep(PosixCommands.Context context, String[] argv)	Sleep command - suspend execution.
static void	sort(PosixCommands.Context context, String[] argv)	Sort command - sort lines of text.
static void	tail(PosixCommands.Context context, String[] argv)	Tail command - display last lines of files.
static void	ttop(PosixCommands.Context context, String[] argv)	Thread monitoring command - display and update sorted information about threads.
static void	watch(PosixCommands.Context context, String[] argv)	Watch command - execute a command repeatedly and display output.
static void	watch(PosixCommands.Context context, String[] argv, PosixCommands.CommandExecutor executor)	Watch command with command executor - execute a command repeatedly and display output.
static void	wc(PosixCommands.Context context, String[] argv)	Word count command - count lines, words, characters, and bytes.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_LS_COLORS

public static final String DEFAULT_LS_COLORS

See Also:

• Constant Field Values

DEFAULT_GREP_COLORS

public static final String DEFAULT_GREP_COLORS

See Also:

• Constant Field Values

Constructor Details

PosixCommands

public PosixCommands()

Method Details

cd

public static void cd(PosixCommands.Context context,
 String[] argv)
               throws Exception

Change directory command.

Changes the current working directory to the specified directory. This version provides validation only and does not actually change the directory. Use the overloaded version with Consumer<Path> for actual directory changing functionality.

Parameters:

context - the execution context

argv - command arguments

Throws:

Exception - if the command fails

See Also:

• cd(Context, String[], Consumer)

cd

public static void cd(PosixCommands.Context context,
 String[] argv,
 Consumer<Path> directoryChanger)
               throws Exception

Change directory command with directory changer.

Changes the current working directory to the specified directory. Supports POSIX-compliant options and behaviors:

• No arguments: change to home directory
• "-": change to previous directory (placeholder)
• "-P": use physical directory structure (resolve symlinks)
• "-L": follow symbolic links (default)

The directoryChanger consumer is called with the resolved path if provided, allowing the caller to actually perform the directory change operation.

Parameters:

context - the execution context

argv - command arguments

directoryChanger - consumer to perform the actual directory change

Throws:

Exception - if the command fails

pwd

public static void pwd(PosixCommands.Context context,
 String[] argv)
                throws Exception

Print working directory command.

Prints the absolute pathname of the current working directory to standard output. This command is equivalent to the POSIX pwd utility.

Parameters:

context - the execution context

argv - command arguments (should be empty except for --help)

Throws:

Exception - if the command fails

echo

public static void echo(PosixCommands.Context context,
 String[] argv)
                 throws Exception

Echo command - display text.

Writes its arguments to standard output, followed by a newline. Supports the -n option to suppress the trailing newline. This command is equivalent to the POSIX echo utility.

Parameters:

context - the execution context

argv - command arguments

Throws:

Exception - if the command fails

echo

public static void echo(PosixCommands.Context context,
 Object[] argv)
                 throws Exception

Echo command - display text (Object array version for compatibility).

Throws:

Exception

cat

public static void cat(PosixCommands.Context context,
 String[] argv)
                throws Exception

Cat command - concatenate and print files.

Reads files sequentially and writes them to standard output. If no files are specified, or if a file is "-", reads from standard input. Supports the -n option to number output lines. This command is equivalent to the POSIX cat utility.

Parameters:

context - the execution context

argv - command arguments

Throws:

Exception - if the command fails

date

public static void date(PosixCommands.Context context,
 String[] argv)
                 throws Exception

Date command - display current date and time.

Displays the current date and time, or a specified date/time. Supports various output formats including ISO 8601, RFC 2822, and RFC 3339. Can parse date strings and display dates from epoch seconds. This command provides functionality similar to the POSIX date utility.

Supported options:

• -u, --utc: Display time in UTC
• -r, --reference: Display time from epoch seconds
• -d, --date: Parse and display specified date string
• -I, --iso-8601: Output in ISO 8601 format
• -R, --rfc-2822: Output in RFC 2822 format
• --rfc-3339: Output in RFC 3339 format

Parameters:

context - the execution context

argv - command arguments

Throws:

Exception - if the command fails

sleep

public static void sleep(PosixCommands.Context context,
 String[] argv)
                  throws Exception

Sleep command - suspend execution.

Suspends execution for a specified number of seconds. This command is equivalent to the POSIX sleep utility.

Parameters:

context - the execution context

argv - command arguments (should contain the number of seconds)

Throws:

Exception - if the command fails

watch

public static void watch(PosixCommands.Context context,
 String[] argv)
                  throws Exception

Watch command - execute a command repeatedly and display output.

Executes a command repeatedly at specified intervals and displays the output. This version uses a basic command executor. For full shell integration, use the overloaded version with a CommandExecutor.

Parameters:

context - the execution context

argv - command arguments

Throws:

Exception - if the command fails

See Also:

• watch(Context, String[], CommandExecutor)

watch

public static void watch(PosixCommands.Context context,
 String[] argv,
 PosixCommands.CommandExecutor executor)
                  throws Exception

Watch command with command executor - execute a command repeatedly and display output.

Executes a command repeatedly at specified intervals and displays the output. The command is executed using the provided CommandExecutor, which allows for full shell integration and complex command execution.

Supported options:

• -n, --interval: Specify the interval between executions (default: 1 second)
• -a, --append: Append output instead of clearing the screen

Parameters:

context - the execution context

argv - command arguments

executor - the command executor for running the watched command

Throws:

Exception - if the command fails

ttop

public static void ttop(PosixCommands.Context context,
 String[] argv)
                 throws Exception

Thread monitoring command - display and update sorted information about threads.

Displays real-time information about Java threads in a top-like interface. Shows thread names, states, CPU usage, and other thread-related information. This command delegates to the TTop utility for full functionality.

Parameters:

context - the execution context

argv - command arguments

Throws:

Exception - if the command fails

nano

public static void nano(PosixCommands.Context context,
 String[] argv)
                 throws Exception

Text editor command - edit files with nano-like interface.

Opens a text editor with a nano-like interface for editing files. Provides basic text editing functionality with keyboard shortcuts similar to the nano editor. This command delegates to the Nano utility.

Parameters:

context - the execution context

argv - command arguments (typically file names to edit)

Throws:

Exception - if the command fails

less

public static void less(PosixCommands.Context context,
 String[] argv)
                 throws Exception

Pager command - view files with less-like interface.

Opens a pager for viewing files with a less-like interface. Supports navigation, searching, and other pager functionality. Can handle multiple files and supports glob patterns. This command delegates to the Less utility for full functionality.

Parameters:

context - the execution context

argv - command arguments (typically file names to view)

Throws:

Exception - if the command fails

clear

public static void clear(PosixCommands.Context context,
 String[] argv)
                  throws Exception

Clear command - clear terminal screen.

Clears the terminal screen by sending the appropriate escape sequence. Only works when connected to a TTY terminal. This command is equivalent to the POSIX clear utility.

Parameters:

context - the execution context

argv - command arguments (should be empty except for --help)

Throws:

Exception - if the command fails

wc

public static void wc(PosixCommands.Context context,
 String[] argv)
               throws Exception

Word count command - count lines, words, characters, and bytes.

Throws:

Exception

head

public static void head(PosixCommands.Context context,
 String[] argv)
                 throws Exception

Head command - display first lines of files.

Throws:

Exception

tail

public static void tail(PosixCommands.Context context,
 String[] argv)
                 throws Exception

Tail command - display last lines of files.

Throws:

Exception

grep

public static void grep(PosixCommands.Context context,
 String[] argv)
                 throws Exception

Grep command - search text patterns.

Throws:

Exception

sort

public static void sort(PosixCommands.Context context,
 String[] argv)
                 throws Exception

Sort command - sort lines of text.

Throws:

Exception

ls

public static void ls(PosixCommands.Context context,
 String[] argv)
               throws Exception

List directory contents command.

Throws:

Exception

getLsColorMap

public static Map<String,String> getLsColorMap(String colorString)

Get color map for ls command.

getColorMap

public static Map<String,String> getColorMap(String colorString)

Get color map from color string.

getLsColorMap

public static Map<String,String> getLsColorMap(PosixCommands.Context session)

getColorMap

public static Map<String,String> getColorMap(PosixCommands.Context session,
 String name,
 String def)

getColorMap

public static Map<String,String> getColorMap(Function<String,Object> variables,
 String name,
 String def)

applyStyle

public static String applyStyle(String text,
 Map<String,String> colors,
 String... types)

Apply style to text using color map.

applyStyle

public static void applyStyle(org.jline.utils.AttributedStringBuilder sb,
 Map<String,String> colors,
 String... types)

Apply style to AttributedStringBuilder using color map.

parseOptions

protected static Options parseOptions(PosixCommands.Context context,
 String[] usage,
 Object[] argv)
                               throws Exception

Throws:

Exception

get

protected static String get(PosixCommands.Context context,
 String name)