/* $Id: xtail.h,v 2.7 2000/06/04 19:02:23 chip Exp $ */


/*****************************************************************************
 *
 * Start of Site-Specific Customizations
 *
 *****************************************************************************/

/*
 * STATUS_ENAB - If defined, a SIGINT causes a summary of the opened files to
 * be displayed, and a SIGQUIT terminates the program.  If not defined,
 * these signals act normally.
 */
#define STATUS_ENAB

/*
 * SLEEP_TIME - Number of seconds between iterations of the checking loop.
 */
#define SLEEP_TIME 1

/*
 * CHECK_COUNT - Recently modified files are checked for changes every time
 * through the checking loop.  We only go looking for changes to
 * not-so-recently modified stuff only once ever CHECK_COUNT iterations
 * through the loop.
 */
#define CHECK_COUNT 5

/*
 * MAX_OPEN - This number of most recently changed files is kept open, and
 * they are checked every iteration through the checking loop.  Keeping these
 * files open improves the performance because we can use "fstat()" rather
 * than "stat()".  Keeping too many files open may overflow your open file
 * table, and will reduce performance by checking more files more frequently.
 */
#define MAX_OPEN 8

/*
 * MAX_ENTRIES - This is *BOGUS*  I should get rid of this.
 */
#define MAX_ENTRIES 512



/*****************************************************************************
 *
 * End of Site-Specific Customizations
 *
 *****************************************************************************/


#define TRUE 1
#define FALSE 0

#define Dprintf if ( !Debug ) ; else (void) fprintf


/*
 * Codes returned by the "stat_entry()" procedure.
 */
#define ENTRY_ERROR	0	/* stat error or permissions error	*/
#define ENTRY_SPECIAL	1	/* entry is a special file		*/
#define ENTRY_FILE	2	/* entry is a regular file		*/
#define ENTRY_DIR	3	/* entry is a directory			*/
#define ENTRY_ZAP	4	/* specified entry doesn't exist	*/


/*
 * Diagnostic message codes.
 *   The ordering of codes must correspond to the "mssg_list[]" defined below.
 */
#define MSSG_NONE	0	/* no message - just reset header	*/
#define MSSG_BANNER	1	/* display banner for file output	*/
#define MSSG_CREATED	2	/* file has been created		*/
#define MSSG_ZAPPED	3	/* file has been deleted		*/
#define MSSG_TRUNC	4	/* file has been truncated		*/
#define MSSG_NOTAFIL	5	/* error - not a regular file or dir	*/
#define MSSG_STAT	6	/* error - stat() failed		*/
#define MSSG_OPEN	7	/* error - open() failed		*/
#define MSSG_SEEK	8	/* error - lseek() failed		*/
#define MSSG_READ	9	/* error - read() failed		*/
#define MSSG_UNKNOWN	10	/* unknown error - must be last in list */


#ifdef INTERN
#   define EXTERN
#else
#   define EXTERN extern
#endif


/*
 * Each item we are watching is stored in a (struct entry_descrip).  These
 * entries are placed in lists, which are managed as (struct entry_list).
 *
 * There are three lists maintained:
 *
 * List_file	All of the regular files we are watching.  We will try to
 *		keep the MAX_OPEN most recently modified files open, and
 *		they will be checked more frequently.
 *
 * List_dir	All of the directories we are watching.  If a file is created
 *		in one of these directories, we will add it to "List_file".
 *
 * List_zap	All the entries which don't exist.  When something appears
 *		under one of these names, the entry will be moved to either
 *		"List_file" or "List_dir", as appropriate.
 */

struct entry_descrip {
    char *name;		/* pathname to the entry			*/
    int fd;		/* opened fd, or <= 0 if not opened		*/
    long size;		/* size of entry last time checked		*/
    long mtime;		/* modification time last time checked		*/
};

struct entry_list {
    struct entry_descrip **list;
    int num_entries;	/* num entries stored in the list		*/
    int max_entries;	/* list allocated to hold this many entries	*/
    int chunk;		/* chunk for growin the list			*/
};

#define ENTRY_LIST_CHUNK 64
#define last_entry(L)	((L)->num_entries - 1)

/*
 * The lists of entries being watched.
 */
EXTERN struct entry_list *List_file;	/* regular files		*/
EXTERN struct entry_list *List_dir;	/* directories			*/
EXTERN struct entry_list *List_zap;	/* nonexistent entries		*/


/*
 * List sorting status.
 *   This flag indicates that "List_file" is sorted, and the right entries
 *   are open.  Anything which possibly effects this state (e.g. an entry
 *   is added to "List_file", the mtime of a file is changed, etc.) must set
 *   this flag FALSE.  We will periodically check this flag and call the
 *   "fixup_open_files()" procedure to resort and organize the list.
 */
EXTERN int Sorted;


/*
 * Entry status control flag.
 *   The procedures which manipulate entries will reset the status information
 *   if this flag is TRUE.  When initializing the lists we want this FALSE.
 *   For example, consider the file size.  When initializing we want to use
 *   the current file size, otherwise we would dump the file from the beginning.
 *   However, later when we notice things are created we want to reset the
 *   size to zero so that we do dump from the beginning.
 */
EXTERN int Reset_status;


EXTERN int Debug;
EXTERN char *Progname;


/*
 * Diagnostic messages produced by the "message()" procedure.
 *   The first "%s" is the entry name.  The second "%s" is the errno descrip.
 */
#ifdef INTERN
    char *mssg_list[] = {
	NULL,							/*MSSG_NONE   */
	"\n*** %s ***\n",					/*MSSG_BANNER */
	"\n*** '%s' has been created ***\n",			/*MSSG_CREATED*/
	"\n*** '%s' has been deleted ***\n",			/*MSSG_ZAPPED */
	"\n*** '%s' has been truncated - rewinding ***\n",	/*MSSG_TRUNC  */
	"\n*** error - '%s' not a file or dir - removed ***\n",	/*MSSG_NOTAFIL*/
	"\n*** error - couldn't stat '%s' (%s) - removed ***\n",/*MSSG_STAT   */
	"\n*** error - couldn't open '%s' (%s) - removed ***\n",/*MSSG_OPEN   */
	"\n*** error - couldn't seek '%s' (%s) - removed ***\n",/*MSSG_SEEK   */
	"\n*** error - couldn't read '%s' (%s) - removed ***\n",/*MSSG_READ   */
	"\n*** error - unknown error on file '%s' ***\n",	/*MSSG_UNKNOWN*/
    };
#else
    extern char *mssg_list[];
#endif


/*
 * Entry management procedures.
 */
struct entry_list *new_entry_list(int chunk);
struct entry_descrip *new_entry(struct entry_list *listp, const char *name);
void rmv_entry(struct entry_list *listp, int entryno);
void move_entry(struct entry_list *dst_listp, struct entry_list *src_listp,
	int src_entryno);
int stat_entry(struct entry_list *listp, int entryno, struct stat *sbuf);
int open_entry(struct entry_list *listp, int entryno);

/*
 * Miscellaneous procedures.
 */
int scan_directory(const char *dirname);
int ecmp(const void *p1, const void *p2);
void fixup_open_files(void);
void message(int sel, const struct entry_descrip *e);
void show_status(void);
char *quit_ch(void);
VOID *safe_malloc(size_t n);
VOID *safe_realloc(VOID *p, size_t n);
char *safe_strdup(const char *p);
char *basename(char *p);
#ifndef HAVE_DIFFTIME
double difftime(time_t t1, time_t t0)
#endif
#ifndef HAVE_STRERROR
char *strerror(int err);
#endif