Quash Shell  0.1
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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

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

Alias for SimpleCommand to denote the end of a command.

See Also
SimpleCommand, Command

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

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

See Also
Command

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

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

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
holdersCommandHolder 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
holderCommandHolder 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
cmdCommand 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
dirPath 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_inIf 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_outIf 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
flagsA 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
cmdThe 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
argsA 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_varName of environment variable to set
valString 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
argsA 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
sigSignal to send to the job
jobJob 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