Functions for interpreting and running commands. More...

#include <stdbool.h>
#include <unistd.h>
#include "command.h"

Functions
const char *	lookup_env (const char *env_var)
	Function to get environment variable values. More...

void	write_env (const char env_var, const char val)
	Function to set and define environment variable values. More...

char *	get_current_directory (bool *should_free)
	Get the real current working directory. More...

void	check_jobs_bg_status ()
	Check on background jobs to see if they have exited.

void	print_job (int job_id, pid_t pid, const char *cmd)
	Print a job to standard out. More...

void	print_job_bg_start (int job_id, pid_t pid, const char *cmd)
	Print the start up of a background job to standard out. More...

void	print_job_bg_complete (int job_id, pid_t pid, const char *cmd)
	Print the completion of a background job to standard out. More...

void	run_generic (GenericCommand cmd)
	Run a generic (non-builtin) command. More...

void	run_echo (EchoCommand cmd)
	Run the builtin echo command. More...

void	run_export (ExportCommand cmd)
	Run the builtin export command. More...

void	run_cd (CDCommand cmd)
	Run the builtin cd (change directory) command. More...

void	run_kill (KillCommand cmd)
	Run the builtin kill command. More...

void	run_pwd ()
	Run the builtin pwd (print working directory) command. More...

void	run_jobs ()
	Run the builtin jobs command to show the jobs list. More...

void	run_script (CommandHolder *holders)
	Common entry point for all commands. More...

Detailed Description

Functions for interpreting and running commands.

Function Documentation

char* get_current_directory ( bool * should_free )

Get the real current working directory.

This is not necessarily the same as the PWD environment variable and setting PWD does not actually change the current working directory.

Parameters

[out] should_free Set this to true if the returned string should be free'd by the caller and false otherwise.

Returns: A string representing the current working directory

const char* lookup_env ( const char * env_var )

Function to get environment variable values.

Parameters

env_var Environment variable to lookup

Returns: String containing the value of the environment variable env_var

void print_job	(	int	job_id,
		pid_t	pid,
		const char *	cmd
	)

Print a job to standard out.

We use the minimum of what a Job structure should contain to pass to this function.

Parameters

job_id	Job identifier number.
pid	Process id of a process belonging to this job.
cmd	String holding an approximation of what the user typed in for the command.

void print_job_bg_complete	(	int	job_id,
		pid_t	pid,
		const char *	cmd
	)

Print the completion of a background job to standard out.

We use the minimum of what a Job should contain to pass to this function.

Parameters

job_id	Job identifier number.
pid	Process id of a process belonging to this job.
cmd	String holding an aproximation of what the user typed in for the command.

void print_job_bg_start	(	int	job_id,
		pid_t	pid,
		const char *	cmd
	)

Print the start up of a background job to standard out.

We use the minimum of what a Job should contain to pass to this function.

Parameters

job_id	Job identifier number.
pid	Process id of a process belonging to this job.
cmd	String holding an aproximation of what the user typed in for the command.

void run_cd ( CDCommand cmd )

Run the builtin cd (change directory) command.

Parameters

cmd	An CDCommand

See also: CDCommand

void run_echo ( EchoCommand cmd )

Run the builtin echo command.

Parameters

cmd	An EchoCommand

See also: EchoCommand

void run_export ( ExportCommand cmd )

Run the builtin export command.

Parameters

cmd	An ExportCommand

See also: ExportCommand

void run_generic ( GenericCommand cmd )

Run a generic (non-builtin) command.

Parameters

cmd	A GenericCommand command

See also: GenericCommand

void run_jobs ( )

Run the builtin jobs command to show the jobs list.

See also: PWDCommand

void run_kill ( KillCommand cmd )

Run the builtin kill command.

Parameters

cmd	A KillCommand

See also: KillCommand

void run_pwd ( )

Run the builtin pwd (print working directory) command.

See also: PWDCommand

void run_script ( CommandHolder * holders )

Common entry point for all commands.

This function resolves the type of the command and calls the relevant run function

Parameters

holders An array of command holders

See also: Command

void write_env	(	const char *	env_var,
		const char *	val
	)

Function to set and define environment variable values.

Parameters

env_var	Environment variable to set
val	String with the value to set the environment variable env_var