1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #if defined(LIBC_SCCS) && !defined(lint) 19 static char sccsid[] = "@(#)scandir.c 5.6 (Berkeley) 02/05/89"; 20 #endif /* LIBC_SCCS and not lint */ 21 22 /* 23 * Scan the directory dirname calling select to make a list of selected 24 * directory entries then sort using qsort and compare routine dcomp. 25 * Returns the number of entries and a pointer to a list of pointers to 26 * struct dirent (through namelist). Returns -1 if there were any errors. 27 */ 28 29 #include <sys/types.h> 30 #include <sys/stat.h> 31 #include <dirent.h> 32 33 /* 34 * The DIRSIZ macro gives the minimum record length which will hold 35 * the directory entry. This requires the amount of space in struct dirent 36 * without the d_name field, plus enough space for the name with a terminating 37 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary. 38 */ 39 #undef DIRSIZ 40 #define DIRSIZ(dp) \ 41 ((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)) 42 43 scandir(dirname, namelist, select, dcomp) 44 char *dirname; 45 struct dirent *(*namelist[]); 46 int (*select)(), (*dcomp)(); 47 { 48 register struct dirent *d, *p, **names; 49 register int nitems; 50 struct stat stb; 51 long arraysz; 52 DIR *dirp; 53 54 if ((dirp = opendir(dirname)) == NULL) 55 return(-1); 56 if (fstat(dirp->dd_fd, &stb) < 0) 57 return(-1); 58 59 /* 60 * estimate the array size by taking the size of the directory file 61 * and dividing it by a multiple of the minimum size entry. 62 */ 63 arraysz = (stb.st_size / 24); 64 names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *)); 65 if (names == NULL) 66 return(-1); 67 68 nitems = 0; 69 while ((d = readdir(dirp)) != NULL) { 70 if (select != NULL && !(*select)(d)) 71 continue; /* just selected names */ 72 /* 73 * Make a minimum size copy of the data 74 */ 75 p = (struct dirent *)malloc(DIRSIZ(d)); 76 if (p == NULL) 77 return(-1); 78 p->d_ino = d->d_ino; 79 p->d_reclen = d->d_reclen; 80 p->d_namlen = d->d_namlen; 81 bcopy(d->d_name, p->d_name, p->d_namlen + 1); 82 /* 83 * Check to make sure the array has space left and 84 * realloc the maximum size. 85 */ 86 if (++nitems >= arraysz) { 87 if (fstat(dirp->dd_fd, &stb) < 0) 88 return(-1); /* just might have grown */ 89 arraysz = stb.st_size / 12; 90 names = (struct dirent **)realloc((char *)names, 91 arraysz * sizeof(struct dirent *)); 92 if (names == NULL) 93 return(-1); 94 } 95 names[nitems-1] = p; 96 } 97 closedir(dirp); 98 if (nitems && dcomp != NULL) 99 qsort(names, nitems, sizeof(struct dirent *), dcomp); 100 *namelist = names; 101 return(nitems); 102 } 103 104 /* 105 * Alphabetic order comparison routine for those who want it. 106 */ 107 alphasort(d1, d2) 108 struct dirent **d1, **d2; 109 { 110 return(strcmp((*d1)->d_name, (*d2)->d_name)); 111 } 112