command.h File Reference

Command structures and functions for defining and managing commands. More...

#include <stdbool.h>

Go to the source code of this file.

Classes
struct	SimpleCommand
	A command which has no arguments. More...
struct	GenericCommand
	Commands that take any number of arguments and are not built into Quash. More...
struct	ExportCommand
	Command to set environment variables. More...
struct	CDCommand
	Command to change directories. More...
struct	KillCommand
	Command to kill a process based on it's job id. More...
union	Command
	Make all command types the same size and interchangeable. More...
struct	CommandHolder
	Contains information about the properties of the command. More...

Macros
#define	REDIRECT_IN   (0x01)
	Flag bit indicating whether a GenericCommand should read from standard in.
#define	REDIRECT_OUT   (0x04)
	Flag bit indicating whether a GenericCommand should write to standard out truncating the original file.
#define	REDIRECT_APPEND   (0x08)
	Flag bit indicating whether a GenericCommand should write to standard out appending its output.
#define	PIPE_IN   (0x10)
	Flag bit indicating whether a GenericCommand should read from a pipe.
#define	PIPE_OUT   (0x20)
	Flag bit indicating whether a GenericCommand should write to a pipe.
#define	BACKGROUND   (0x40)
	Flag bit indicating whether a GenericCommand should be run in the background.

Typedefs
typedef enum CommandType	CommandType
	All possible types of commands. More...
typedef struct SimpleCommand	SimpleCommand
	A command which has no arguments. More...
typedef struct GenericCommand	GenericCommand
	Commands that take any number of arguments and are not built into Quash. More...
typedef GenericCommand	EchoCommand
	Alias for GenericCommand to denote a command to print strings. More...
typedef struct ExportCommand	ExportCommand
	Command to set environment variables. More...
typedef struct CDCommand	CDCommand
	Command to change directories. More...
typedef struct KillCommand	KillCommand
	Command to kill a process based on it's job id. More...
typedef SimpleCommand	PWDCommand
	Alias for SimpleCommand to denote a print working directory command. More...
typedef SimpleCommand	JobsCommand
	Alias for SimpleCommand to denote a print jobs list. More...
typedef SimpleCommand	ExitCommand
	Alias for SimpleCommand to denote a termination of the program. More...
typedef SimpleCommand	EOCCommand
	Alias for SimpleCommand to denote the end of a command. More...
typedef union Command	Command
	Make all command types the same size and interchangeable. More...
typedef struct CommandHolder	CommandHolder
	Contains information about the properties of the command. More...

Enumerations
enum	CommandType {   EOC = 0, GENERIC, ECHO, EXPORT,   KILL, CD, PWD, JOBS,   EXIT }
	All possible types of commands. More...

Functions
CommandHolder	mk_command_holder (char *redirect_in, char *redirect_out, char flags, Command cmd)
	Create a CommandHolder structure and return a copy. More...
Command	mk_generic_command (char **args)
	Create a GenericCommand structure and return a copy. More...
Command	mk_echo_command (char **args)
	Create a EchoCommand structure and return a copy. More...
Command	mk_export_command (char *env_var, char *val)
	Create a ExportCommand structure and return a copy. More...
Command	mk_cd_command (char *dir)
	Create a CDCommand structure and return a copy. More...
Command	mk_kill_command (char *sig, char *job)
	Create a KillCommand structure and return a copy. More...
Command	mk_pwd_command ()
	Create a PWDCommand structure and return a copy. More...
Command	mk_jobs_command ()
	Create a JobsCommand structure and return a copy. More...
Command	mk_exit_command ()
	Create a ExitCommand structure and return a copy. More...
Command	mk_eoc ()
	Create a EOCCommand structure and return a copy. More...
CommandType	get_command_type (Command cmd)
	Get the type of the command. More...
CommandType	get_command_holder_type (CommandHolder holder)
	Get the type of the Command in the CommandHolder. More...
void	debug_print_script (const CommandHolder *holders)
	Print all commands in the script with print_command() More...

Detailed Description

Command structures and functions for defining and managing commands.

Typedef Documentation

typedef struct CDCommand CDCommand

Command to change directories.

See also

realpath(), Command

typedef union Command Command

Make all command types the same size and interchangeable.

This is useful for arrays or making a common entry point for all command types. The exact type information can be recovered later with the get_command_type() function.

See also

get_command_type, SimpleCommand, GenericCommand, EchoCommand, ExportCommand, CDCommand, KillCommand, PWDCommand, JobsCommand, ExitCommand, EOCCommand

typedef struct CommandHolder CommandHolder

Contains information about the properties of the command.

See also

REDIRECT_IN, REDIRECT_OUT, REDIRECT_APPEND, PIPE_IN, PIPE_OUT, BACKGROUND, Command

typedef enum CommandType CommandType

All possible types of commands.

These are useful for recovering what the actual type of a command is if the command is placed in a Command union

See also

Command

typedef GenericCommand EchoCommand

Alias for GenericCommand to denote a command to print strings.

Note

EchoCommand is similar to a generic command but is a builtin command

See also

GenericCommand, Command

typedef SimpleCommand EOCCommand

Alias for SimpleCommand to denote the end of a command.

See also

SimpleCommand, Command

typedef SimpleCommand ExitCommand

Alias for SimpleCommand to denote a termination of the program.

See also

end_main_loop(), SimpleCommand, Command

typedef struct ExportCommand ExportCommand

Command to set environment variables.

See also

CommandType, lookup_env(), write_env(), Command

typedef struct GenericCommand GenericCommand

Commands that take any number of arguments and are not built into Quash.

See also

Command

typedef SimpleCommand JobsCommand

Alias for SimpleCommand to denote a print jobs list.

See also

SimpleCommand, Command, Job

typedef struct KillCommand KillCommand

Command to kill a process based on it's job id.

See also

CommandType, Command

typedef SimpleCommand PWDCommand

Alias for SimpleCommand to denote a print working directory command.

See also

SimpleCommand, Command

typedef struct SimpleCommand SimpleCommand

A command which has no arguments.

All command structures can be correctly read as a SimpleCommand since they all have the CommandType field as the first field.

See also

Command, CommandType

Enumeration Type Documentation

enum CommandType

All possible types of commands.

These are useful for recovering what the actual type of a command is if the command is placed in a Command union

See also

Command

Function Documentation

void debug_print_script

(

const CommandHolder *

holders

)

Print all commands in the script with print_command()

Note

This only works when the DEBUG macro is defined

Parameters

holders

CommandHolder array to print

See also

CommandHolder

CommandType get_command_holder_type

(

CommandHolder

holder

)

Get the type of the Command in the CommandHolder.

Uses the property that all Command variants can be cast to SimpleCommand to extract the CommandType of the Command.

Parameters

holder

CommandHolder from which this function extracts the CommandType

Returns

The resulting CommandType of the cmd parameter

See also

CommandType, CommandHolder, SimpleCommand

CommandType get_command_type

(

Command

cmd

)

Get the type of the command.

Uses the property that all Command variants can be cast to SimpleCommand to extract the CommandType of the Command.

Parameters

cmd	Command from which this function extracts the CommandType

Returns

The resulting CommandType of the cmd parameter

See also

CommandType, Command, SimpleCommand

Command mk_cd_command

(

char *

dir

)

Create a CDCommand structure and return a copy.

Parameters

dir	Path to the directory we wish to change to

Returns

Copy of constructed CDCommand as a Command

See also

realpath(), Command, CDCommand

CommandHolder mk_command_holder	(	char *	redirect_in,
		char *	redirect_out,
		char	flags,
		Command	cmd
	)

Create a CommandHolder structure and return a copy.

Parameters

redirect_in	If the REDIRECT_IN flag is set, Quash should redirect the standard input stream of the command to read from a file stored in this string
redirect_out	If the REDIRECT_OUT flag is set, Quash should redirect the standard output stream of the command to write to a file stored in this string
flags	A set of bits that hold information about how to execute the command. The properties can be extracted from the flags field by using a bit-wise & (i.e. flags & PIPE_IN) are macro defined as: REDIRECT_IN REDIRECT_OUT REDIRECT_APPEND PIPE_IN PIPE_OUT BACKGROUND
cmd	The Command the CommandHolder should copy and hold on to

Returns

Copy of constructed CommandHolder

See also

CommandType, REDIRECT_IN, REDIRECT_OUT, REDIRECT_APPEND, PIPE_IN, PIPE_OUT, BACKGROUND, Command, CommandHolder

Command mk_echo_command

(

char **

args

)

Create a EchoCommand structure and return a copy.

Parameters

args	A NULL terminated array of strings containing the strings passed to echo

Returns

Copy of constructed EchoCommand as a Command

See also

Command, EchoCommand

Command mk_eoc

(

)

Create a EOCCommand structure and return a copy.

Returns

Copy of constructed EOCCommand as a Command

See also

Command, EOCCommand

Command mk_exit_command

(

)

Create a ExitCommand structure and return a copy.

Returns

Copy of constructed ExitCommand as a Command

See also

Command, ExitCommand

Command mk_export_command	(	char *	env_var,
		char *	val
	)

Create a ExportCommand structure and return a copy.

Parameters

env_var	Name of environment variable to set
val	String that should be stored in env_var environment variable

Returns

Copy of constructed ExportCommand as a Command

See also

lookup_env(), write_env(), Command, ExportCommand

Command mk_generic_command

(

char **

args

)

Create a GenericCommand structure and return a copy.

Parameters

args	A NULL terminated array of strings ready to pass to the exec family of functions

Returns

Copy of constructed GenericCommand as a Command

See also

Command, GenericCommand

Command mk_jobs_command

(

)

Create a JobsCommand structure and return a copy.

Returns

Copy of constructed JobsCommand as a Command

See also

Command, JobsCommand

Command mk_kill_command	(	char *	sig,
		char *	job
	)

Create a KillCommand structure and return a copy.

Parameters

sig	Signal to send to the job
job	Job id number

Returns

Copy of constructed KillCommand as a Command

See also

Command, KillCommand

Command mk_pwd_command

(

)

Create a PWDCommand structure and return a copy.

Returns

Copy of constructed PWDCommand as a Command

See also

Command, PWDCommand