main.c File Reference

External ulility mycat. More...

Classes
struct	file

Enumerations
enum	error_code {   UNKNOWN_OPT = 1 , NO_FILES = 2 , ALLOC_ERR = 3 , OPEN_ERR = 4 ,   STAT_ERR = 5 , READ_ERR = 6 , WRITE_ERR = 7 }

Functions
void	herror (error_code code, int use_errno,...)
void	help (void)
int	wrbuf (int fd, const char *buffer, ssize_t size)
int	rdbuf (int fd, char *buffer, ssize_t size)
void	chtoh (char c, char *hex_escape)
ssize_t	buftoh (const char *buffer, ssize_t size, char *fbuffer)
void	rfiles (int argc, char *argv[], struct file *files)
void	cat (const struct file *file, int a_flag, char *buffer, char *fbuffer)
int	main (int argc, char *argv[])

Variables
static const char *	error_messages []

Detailed Description

External ulility mycat.

Enumeration Type Documentation

error_code

enum error_code

Error codes

Function Documentation

buftoh()

ssize_t buftoh	(	const char *	buffer,
		ssize_t	size,
		char *	fbuffer )

Escapes non-printable characters in buffer and writes the result to fbuffer

Parameters

buffer	Buffer to filter
size	Size of the buffer
fbuffer	Buffer to write the result to

Returns

Number of bytes written to fbuffer

cat()

void cat	(	const struct file *	file,
		int	a_flag,
		char *	buffer,
		char *	fbuffer )

Reads file file and writes it to stdout

Parameters

file	File to read
a_flag	If set to 1, non-printable characters will be replaced with their hexadecimal escape sequences
buffer	Buffer to read to
fbuffer	Auxiliary buffer for a_flag

Note

Returns nothing. Exits on error.

Warning

fbuffer may be NULL if a_flag is not set, otherwise behavior is undefined. fbuffer must be at least

4 * BUFFER_SIZE 

bytes long if a_flag is set.

chtoh()

void chtoh	(	char	c,
		char *	hex_escape )

Converts a character to its hexadecimal escape sequence

Parameters

c	Character to convert
hex_escape	Buffer to write the escape sequence to

help()

void help

(

void

)

Prints help message to stdout

herror()

void herror	(	error_code	code,
		int	use_errno,
			... )

Prints error message to stderr and exits with the specified code

See also

error_code

Parameters

code	Error code
use_errno	If set to 1, the description of errno will be appended to the error message
...	Additional arguments for the error message

rdbuf()

int rdbuf	(	int	fd,
		char *	buffer,
		ssize_t	size )

Reads size bytes from fd to buffer

Parameters

fd	File descriptor
buffer	Buffer to read to
size	Size of the buffer

Returns

0 on success, -1 on error

Note

Automatically retries if read() is interrupted

rfiles()

void rfiles	(	int	argc,
		char *	argv[],
		struct file *	files )

Opens files from argv and saves their metadata to files

Parameters

argc	Number of files
argv	Array of filenames
files	Array of struct file

Note

Returns nothing. Exits on error.

wrbuf()

int wrbuf	(	int	fd,
		const char *	buffer,
		ssize_t	size )

Writes size bytes from buffer to fd

Parameters

fd	File descriptor
buffer	Buffer to write
size	Size of the buffer

Returns

0 on success, -1 on error

Note

Automatically retries if write() is interrupted

Variable Documentation

error_messages

const char* error_messages[]

static

Initial value:

= {
        [UNKNOWN_OPT] = "Unknown option",
        [NO_FILES]    = "No input files provided",
        [ALLOC_ERR]   = "Memory allocation error",
        [OPEN_ERR]    = "Cannot open file %s",
        [STAT_ERR]    = "Cannot stat file %s",
        [READ_ERR]    = "Cannot read from file %s",
        [WRITE_ERR]   = "Cannot write to stdout"
}

Error messages