3 * $Id: fwatch.c,v 1.2 2004/04/08 01:36:11 mdw Exp $
5 * Watch a file for changes
7 * (c) 2001 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the mLib utilities library.
14 * mLib is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
19 * mLib is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
24 * You should have received a copy of the GNU Library General Public
25 * License along with mLib; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
30 /*----- Header files ------------------------------------------------------*/
34 #include <sys/types.h>
39 /*----- Main code ---------------------------------------------------------*/
41 /* --- @doupdate@ --- *
43 * Arguments: @fwatch *f@ = pointer to an @fwatch@ structure
44 * @struct stat *st@ = pointer to file state
45 * @int err@ = whether there was an error
47 * Returns: Nonzero if the file has changed.
49 * Use: Updates the information in an @fwatch@ block.
52 static void copy(fwatch
*f
, struct stat
*st
)
54 f
->dev
= st
->st_dev
; f
->ino
= st
->st_ino
;
55 f
->mtime
= st
->st_mtime
; f
->size
= st
->st_size
;
56 f
->mode
= st
->st_mode
;
57 f
->uid
= st
->st_uid
; f
->gid
= st
->st_gid
;
60 static int doupdate(fwatch
*f
, struct stat
*st
, int err
)
62 /* --- Fiddle with the error state --- *
64 * Only the presence or absence of error is interesting to someone wanting
71 if (!err
!= !f
->err
) {
80 /* --- Check everything else --- */
82 if (st
->st_dev
!= f
->dev
|| st
->st_ino
!= f
->ino
||
83 st
->st_mtime
!= f
->mtime
|| st
->st_size
!= f
->size
||
84 st
->st_mode
!= f
->mode
||
85 st
->st_uid
!= f
->uid
|| st
->st_gid
!= f
->gid
) {
92 /* --- @fwatch_init@, @fwatch_update@, etc --- *
94 * Arguments: @fwatch *f@ = pointer to an @fwatch@ structure
95 * @const char *name@ = name of the file to watch
96 * @int fd@ = a file descriptor to watch
98 * Returns: The @update@ functions return nonzero if the file has
101 * Use: Stores information about a file which can be used to watch
102 * for changes. The structures may be freed without telling
106 void fwatch_init(fwatch
*f
, const char *name
)
109 memset(f
, 0, sizeof(*f
));
110 doupdate(f
, &st
, stat(name
, &st
));
113 void fwatch_initfd(fwatch
*f
, int fd
)
116 memset(f
, 0, sizeof(*f
));
117 doupdate(f
, &st
, fstat(fd
, &st
));
120 int fwatch_update(fwatch
*f
, const char *name
)
123 return (doupdate(f
, &st
, stat(name
, &st
)));
126 int fwatch_updatefd(fwatch
*f
, int fd
)
129 return (doupdate(f
, &st
, fstat(fd
, &st
)));
132 /*----- That's all, folks -------------------------------------------------*/