include/linux/seq_file.h

#ifndef _LINUX_SEQ_FILE_H
#define _LINUX_SEQ_FILE_H
#ifdef __KERNEL__

#include <linux/types.h>
#include <linux/string.h>
#include <linux/mutex.h>

struct seq_operations;
struct file;
struct path;
struct inode;
struct dentry;

struct seq_file {
	char *buf;
	size_t size;
	size_t from;
	size_t count;
	loff_t index;
	u64 version;
	struct mutex lock;
	const 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);
};

#define SEQ_SKIP 1

int seq_open(struct file *, const struct seq_operations *);
ssize_t seq_read(struct file *, char __user *, 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 *);
int seq_putc(struct seq_file *m, char c);
int seq_puts(struct seq_file *m, const char *s);

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

int seq_path(struct seq_file *, struct path *, char *);
int seq_dentry(struct seq_file *, struct dentry *, char *);
int seq_path_root(struct seq_file *m, struct path *path, struct path *root,
		  char *esc);

int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
int single_release(struct inode *, struct file *);
void *__seq_open_private(struct file *, const struct seq_operations *, int);
int seq_open_private(struct file *, const struct seq_operations *, int);
int seq_release_private(struct inode *, struct file *);

#define SEQ_START_TOKEN ((void *)1)

/*
 * Helpers for iteration over list_head-s in seq_files
 */

extern struct list_head *seq_list_start(struct list_head *head,
		loff_t pos);
extern struct list_head *seq_list_start_head(struct list_head *head,
		loff_t pos);
extern struct list_head *seq_list_next(void *v, struct list_head *head,
		loff_t *ppos);

#endif
#endif