1 /* Copyright (c) 1982 Regents of the University of California */ 2 3 static char sccsid[] = "@(#)seekdir.c 4.7 11/14/82"; 4 5 #include <sys/param.h> 6 #include <dir.h> 7 8 /* 9 * seek to an entry in a directory. 10 * Only values returned by ``telldir'' should be passed to seekdir. 11 */ 12 void 13 seekdir(dirp, loc) 14 register DIR *dirp; 15 long loc; 16 { 17 long curloc, base, offset; 18 struct direct *dp; 19 20 curloc = telldir(dirp); 21 if (loc == curloc) 22 return; 23 base = loc & ~(DIRBLKSIZ - 1); 24 offset = loc & (DIRBLKSIZ - 1); 25 if (dirp->dd_loc != 0 && (curloc & ~(DIRBLKSIZ - 1)) == base) { 26 dirp->dd_loc = offset; 27 return; 28 } 29 lseek(dirp->dd_fd, base, 0); 30 dirp->dd_loc = 0; 31 while (dirp->dd_loc < offset) { 32 dp = readdir(dirp); 33 if (dp == NULL) 34 return; 35 } 36 } 37