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 5.5 (Berkeley) 01/16/89"; 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 register char *cp1, *cp2; 51 struct stat stb; 52 long arraysz; 53 DIR *dirp; 54 55 if ((dirp = opendir(dirname)) == NULL) 56 return(-1); 57 if (fstat(dirp->dd_fd, &stb) < 0) 58 return(-1); 59 60 /* 61 * estimate the array size by taking the size of the directory file 62 * and dividing it by a multiple of the minimum size entry. 63 */ 64 arraysz = (stb.st_size / 24); 65 names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *)); 66 if (names == NULL) 67 return(-1); 68 69 nitems = 0; 70 while ((d = readdir(dirp)) != NULL) { 71 if (select != NULL && !(*select)(d)) 72 continue; /* just selected names */ 73 /* 74 * Make a minimum size copy of the data 75 */ 76 p = (struct dirent *)malloc(DIRSIZ(d)); 77 if (p == NULL) 78 return(-1); 79 p->d_ino = d->d_ino; 80 p->d_reclen = d->d_reclen; 81 p->d_namlen = d->d_namlen; 82 for (cp1 = p->d_name, cp2 = d->d_name; *cp1++ = *cp2++; ); 83 /* 84 * Check to make sure the array has space left and 85 * realloc the maximum size. 86 */ 87 if (++nitems >= arraysz) { 88 if (fstat(dirp->dd_fd, &stb) < 0) 89 return(-1); /* just might have grown */ 90 arraysz = stb.st_size / 12; 91 names = (struct dirent **)realloc((char *)names, 92 arraysz * sizeof(struct dirent *)); 93 if (names == NULL) 94 return(-1); 95 } 96 names[nitems-1] = p; 97 } 98 closedir(dirp); 99 if (nitems && dcomp != NULL) 100 qsort(names, nitems, sizeof(struct dirent *), dcomp); 101 *namelist = names; 102 return(nitems); 103 } 104 105 /* 106 * Alphabetic order comparison routine for those who want it. 107 */ 108 alphasort(d1, d2) 109 struct dirent **d1, **d2; 110 { 111 return(strcmp((*d1)->d_name, (*d2)->d_name)); 112 } 113