x-sys.h File Reference

System-level function wrappers. More...

#include "x.h"
#include <stdio.h>
#include <unistd.h>

Go to the source code of this file.

Macros
#define	X_SYS_EOF   EOF
#define	X_SYS_EXIT_SUCCESS   0
#define	X_SYS_EXIT_FAILURE   1

Functions
System Functions
void *	x_sys_malloc (size_t size)
void	x_sys_free (void *ptr)
ssize_t	x_sys_read (int fd, void *p_buf, size_t size)
ssize_t	x_sys_write (int fd, const void *p_buf, size_t size)
void	x_sys_exit (int status)
int	x_sys_open (const char *path, int flags)
int	x_sys_close (int fd)
int	x_sys_read_char (int fd)

Detailed Description

System-level function wrappers.

Thin wrappers around OS/libc primitives for memory allocation, file I/O, and process control. Each wrapper can be redirected at compile time via the X_SYS_FUNC macro.

Author

Jon Ruttan (jonru.nosp@m.ttan.nosp@m.@gmai.nosp@m.l.co.nosp@m.m)

Copyright

2021 Jon Ruttan @license MIT No Attribution (MIT-0)

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Macro Definition Documentation

X_SYS_EOF

#define X_SYS_EOF   EOF

End-of-file sentinel value.

X_SYS_EXIT_FAILURE

#define X_SYS_EXIT_FAILURE   1

Failure process exit status.

X_SYS_EXIT_SUCCESS

#define X_SYS_EXIT_SUCCESS   0

Successful process exit status.

Function Documentation

x_sys_close()

int x_sys_close

(

int

fd

)

Close a file descriptor.

Close a file descriptor.

Parameters

fd	The file descriptor to close.

Returns

0 on success, -1 on error.

x_sys_exit()

void x_sys_exit

(

int

status

)

Terminate the process.

Terminate the process.

Parameters

status

Exit status code returned to the parent process.

x_sys_free()

void x_sys_free

(

void *

ptr

)

Free a previously allocated memory block.

Free a previously allocated memory block.

Parameters

ptr	Pointer to the memory block to free.

x_sys_malloc()

void * x_sys_malloc

(

size_t

size

)

Allocate a memory block from the heap.

Allocate a memory block from the heap.

Parameters

size	The number of bytes to allocate.

Returns

A pointer to the allocated memory, or NULL on failure.

x_sys_open()

int x_sys_open	(	const char *	path,
		int	flags
	)

Open a file by path.

Open a file.

Parameters

path	The file path to open.
flags	Open flags (e.g. O_RDONLY).

Returns

A file descriptor on success, or -1 on error.

x_sys_read()

ssize_t x_sys_read	(	int	fd,
		void *	p_buf,
		size_t	size
	)

Read bytes from a file descriptor.

Read from a file descriptor.

Parameters

fd	File descriptor to read from.
p_buf	Pointer to the destination buffer.
size	Maximum number of bytes to read.

Returns

The number of bytes read, or -1 on error.

x_sys_read_char()

int x_sys_read_char

(

int

fd

)

Read a single character from a file descriptor, or X_SYS_EOF.

Read a single character from a file descriptor.

Parameters

fd	File descriptor to read from.

Returns

The character read, or X_SYS_EOF on error or end-of-file.

x_sys_write()

ssize_t x_sys_write	(	int	fd,
		const void *	p_buf,
		size_t	size
	)

Write bytes to a file descriptor.

Write to a file descriptor.

Parameters

fd	File descriptor to write to.
p_buf	Pointer to the source buffer.
size	Number of bytes to write.

Returns

The number of bytes written, or -1 on error.