1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 15 unchanged lines hidden (view full) --- 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. |
32 * 33 * $FreeBSD: head/lib/libc/gen/telldir.c 69656 2000-12-06 03:15:49Z deischen $ |
34 */ 35 36#if defined(LIBC_SCCS) && !defined(lint) 37static char sccsid[] = "@(#)telldir.c 8.1 (Berkeley) 6/4/93"; 38#endif /* LIBC_SCCS and not lint */ 39 40#include <sys/param.h> 41#include <dirent.h> --- 8 unchanged lines hidden (view full) --- 50#define SINGLEUSE 51 52/* 53 * One of these structures is malloced to describe the current directory 54 * position each time telldir is called. It records the current magic 55 * cookie returned by getdirentries and the offset within the buffer 56 * associated with that return value. 57 */ |
58struct _ddloc { 59 LIST_ENTRY(_ddloc) loc_lqe; /* entry in list */ |
60 long loc_index; /* key associated with structure */ 61 long loc_seek; /* magic cookie returned by getdirentries */ 62 long loc_loc; /* offset of entry in buffer */ |
63}; 64 |
65/* 66 * return a pointer into a directory 67 */ 68long 69telldir(dirp) |
70 DIR *dirp; |
71{ |
72 struct _ddloc *lp; |
73 |
74 if ((lp = (struct _ddloc *)malloc(sizeof(struct _ddloc))) == NULL) |
75 return (-1); |
76 lp->loc_index = dirp->dd_loccnt++; |
77 lp->loc_seek = dirp->dd_seek; 78 lp->loc_loc = dirp->dd_loc; |
79 LIST_INSERT_HEAD(&dirp->dd_locq, lp, loc_lqe); 80 return (lp->loc_index); |
81} 82 83/* 84 * seek to an entry in a directory. 85 * Only values returned by "telldir" should be passed to seekdir. 86 */ 87void 88_seekdir(dirp, loc) |
89 DIR *dirp; |
90 long loc; 91{ |
92 struct _ddloc *lp; |
93 struct dirent *dp; 94 |
95 LIST_FOREACH(lp, &dirp->dd_locq, loc_lqe) { |
96 if (lp->loc_index == loc) 97 break; |
98 } 99 if (lp == NULL) 100 return; 101 if (lp->loc_loc == dirp->dd_loc && lp->loc_seek == dirp->dd_seek) 102 goto found; 103 (void) lseek(dirp->dd_fd, (off_t)lp->loc_seek, SEEK_SET); 104 dirp->dd_seek = lp->loc_seek; 105 dirp->dd_loc = 0; 106 while (dirp->dd_loc < lp->loc_loc) { 107 dp = readdir(dirp); 108 if (dp == NULL) 109 break; 110 } 111found: 112#ifdef SINGLEUSE |
113 LIST_REMOVE(lp, loc_lqe); |
114 free((caddr_t)lp); 115#endif 116} 117 118/* 119 * Reclaim memory for telldir cookies which weren't used. 120 */ 121void 122_reclaim_telldir(dirp) |
123 DIR *dirp; |
124{ |
125 struct _ddloc *lp; 126 struct _ddloc *templp; |
127 |
128 lp = LIST_FIRST(&dirp->dd_locq); 129 while (lp != NULL) { 130 templp = lp; 131 lp = LIST_NEXT(lp, loc_lqe); 132 free(templp); |
133 } |
134 LIST_INIT(&dirp->dd_locq); |
135} |