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 -------------------------------------------------*/