3 * $Id: fwatch.c,v 1.1 2001/02/03 18:43:56 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 /*----- Revision history --------------------------------------------------*
33 * Revision 1.1 2001/02/03 18:43:56 mdw
34 * New feature: watch a file for changes.
38 /*----- Header files ------------------------------------------------------*/
42 #include <sys/types.h>
47 /*----- Main code ---------------------------------------------------------*/
49 /* --- @doupdate@ --- *
51 * Arguments: @fwatch *f@ = pointer to an @fwatch@ structure
52 * @struct stat *st@ = pointer to file state
53 * @int err@ = whether there was an error
55 * Returns: Nonzero if the file has changed.
57 * Use: Updates the information in an @fwatch@ block.
60 static void copy(fwatch
*f
, struct stat
*st
)
62 f
->dev
= st
->st_dev
; f
->ino
= st
->st_ino
;
63 f
->mtime
= st
->st_mtime
; f
->size
= st
->st_size
;
64 f
->mode
= st
->st_mode
;
65 f
->uid
= st
->st_uid
; f
->gid
= st
->st_gid
;
68 static int doupdate(fwatch
*f
, struct stat
*st
, int err
)
70 /* --- Fiddle with the error state --- *
72 * Only the presence or absence of error is interesting to someone wanting
79 if (!err
!= !f
->err
) {
88 /* --- Check everything else --- */
90 if (st
->st_dev
!= f
->dev
|| st
->st_ino
!= f
->ino
||
91 st
->st_mtime
!= f
->mtime
|| st
->st_size
!= f
->size
||
92 st
->st_mode
!= f
->mode
||
93 st
->st_uid
!= f
->uid
|| st
->st_gid
!= f
->gid
) {
100 /* --- @fwatch_init@, @fwatch_update@, etc --- *
102 * Arguments: @fwatch *f@ = pointer to an @fwatch@ structure
103 * @const char *name@ = name of the file to watch
104 * @int fd@ = a file descriptor to watch
106 * Returns: The @update@ functions return nonzero if the file has
109 * Use: Stores information about a file which can be used to watch
110 * for changes. The structures may be freed without telling
114 void fwatch_init(fwatch
*f
, const char *name
)
117 memset(f
, 0, sizeof(*f
));
118 doupdate(f
, &st
, stat(name
, &st
));
121 void fwatch_initfd(fwatch
*f
, int fd
)
124 memset(f
, 0, sizeof(*f
));
125 doupdate(f
, &st
, fstat(fd
, &st
));
128 int fwatch_update(fwatch
*f
, const char *name
)
131 return (doupdate(f
, &st
, stat(name
, &st
)));
134 int fwatch_updatefd(fwatch
*f
, int fd
)
137 return (doupdate(f
, &st
, fstat(fd
, &st
)));
140 /*----- That's all, folks -------------------------------------------------*/