seq_file.h

unxi下共享内存的使用

#ifndef _LINUX_SEQ_FILE_H
#define _LINUX_SEQ_FILE_H
#ifdef __KERNEL__

struct seq_operations;

struct seq_file {
	char *buf;
	size_t size;
	size_t from;
	size_t count;
	loff_t index;
	struct semaphore sem;
	struct seq_operations *op;
	void *private;
};

struct seq_operations {
	void * (*start) (struct seq_file *m, loff_t *pos);
	void (*stop) (struct seq_file *m, void *v);
	void * (*next) (struct seq_file *m, void *v, loff_t *pos);
	int (*show) (struct seq_file *m, void *v);
};

int seq_open(struct file *, struct seq_operations *);
ssize_t seq_read(struct file *, char *, size_t, loff_t *);
loff_t seq_lseek(struct file *, loff_t, int);
int seq_release(struct inode *, struct file *);
int seq_escape(struct seq_file *, const char *, const char *);

static inline int seq_putc(struct seq_file *m, char c)
{
	if (m->count < m->size) {
		m->buf[m->count++] = c;
		return 0;
	}
	return -1;
}

static inline int seq_puts(struct seq_file *m, const char *s)
{
	int len = strlen(s);
	if (m->count + len < m->size) {
		memcpy(m->buf + m->count, s, len);
		m->count += len;
		return 0;
	}
	m->count = m->size;
	return -1;
}

int seq_printf(struct seq_file *, const char *, ...)
	__attribute__ ((format (printf,2,3)));

#endif
#endif