internal_commands.h File Reference

This header file contains declarations for the internal commands. More...

#include <stdbool.h>

Typedefs
typedef bool	option

Functions
int	cd (int nargs, char **args)
	Change the shell working directory.
int	echo (int nargs, char **args)
	Write arguments to the standard output.
int	history (int nargs, char **args)
	Print the history of commands.
int	ls (int nargs, char **args)
	List directory contents.
int	pinfo (pid_t pid)
int	pwd (int nargs, char **args)
	Print the full filename of the current working directory.
void	quit_shell_with_status (int status)
	Quit the shell.
void	quit_shell ()
	Quit the shell with status 0.
int	search (int nargs, char **args)
	Search for a given file or folder under the current directory recursively.

Detailed Description

This header file contains declarations for the internal commands.

Typedef Documentation

option

typedef bool option

Function Documentation

cd()

int cd	(	int	nargs,
		char **	args )

Change the shell working directory.

If no path is provided, changes the current directory to /.

echo()

int echo	(	int	nargs,
		char **	args )

Write arguments to the standard output.

Display the ARGs, separated by a single space character and followed by a newline, on the standard output.

Options:

• -c - separate arguments with commas
• -n - no newline at the end
• -l - format output as a list

history()

int history	(	int	nargs,
		char **	args )

Print the history of commands.

If no option is specified, prints the last 5 commands.

Options:

• -c - clear the history
• -r - read the history file and write to the history list
• -w - write the history list to the history file

ls()

int ls	(	int	nargs,
		char **	args )

List directory contents.

List information about the FILEs (the current directory by default).

Options:

• -a - do not ignore entries starting with .
• -l - use a long listing format

pinfo()

int pinfo

(

pid_t

pid

)

Sample output:

pid -- 231
Process Status -- {R/S/S+/Z}
memory -- 67854 {Virtual Memory}
Executable Path -- ./cshell

Process status codes:

1. R/R+: Running
2. S/S+: Sleeping in an interruptible wait
3. Z: Zombie
4. T: Stopped (on a signal)

Note: “+” must be added to the status code if the process is in the foreground.

Parameters

pid	pid of the process, -1 for the parent process, 0 for the current process

Returns

int 0 on success, -1 on failure

pwd()

int pwd	(	int	nargs,
		char **	args )

Print the full filename of the current working directory.

If no option is specified, -P is assumed. Option -L overrides -P when both are used together.

Options:

• -L - use PWD from environment
• -P - resolves symlinks to get the current working directory.

quit_shell()

void quit_shell

(

)

Quit the shell with status 0.

quit_shell_with_status()

void quit_shell_with_status

(

int

status

)

Quit the shell.

Exits the shell with the given status.

Parameters

status

exit status

search()

int search	(	int	nargs,
		char **	args )

Search for a given file or folder under the current directory recursively.

Prints True or False to stdout depending on whether the file or folder exists.