1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)scandir.c 8.1 (Berkeley) 06/04/93"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 /* 13 * Scan the directory dirname calling select to make a list of selected 14 * directory entries then sort using qsort and compare routine dcomp. 15 * Returns the number of entries and a pointer to a list of pointers to 16 * struct dirent (through namelist). Returns -1 if there were any errors. 17 */ 18 19 #include <sys/types.h> 20 #include <sys/stat.h> 21 #include <dirent.h> 22 #include <stdlib.h> 23 #include <string.h> 24 25 /* 26 * The DIRSIZ macro gives the minimum record length which will hold 27 * the directory entry. This requires the amount of space in struct dirent 28 * without the d_name field, plus enough space for the name with a terminating 29 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary. 30 */ 31 #undef DIRSIZ 32 #define DIRSIZ(dp) \ 33 ((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)) 34 35 int 36 scandir(dirname, namelist, select, dcomp) 37 const char *dirname; 38 struct dirent ***namelist; 39 int (*select) __P((struct dirent *)); 40 int (*dcomp) __P((const void *, const void *)); 41 { 42 register struct dirent *d, *p, **names; 43 register size_t nitems; 44 struct stat stb; 45 long arraysz; 46 DIR *dirp; 47 48 if ((dirp = opendir(dirname)) == NULL) 49 return(-1); 50 if (fstat(dirp->dd_fd, &stb) < 0) 51 return(-1); 52 53 /* 54 * estimate the array size by taking the size of the directory file 55 * and dividing it by a multiple of the minimum size entry. 56 */ 57 arraysz = (stb.st_size / 24); 58 names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *)); 59 if (names == NULL) 60 return(-1); 61 62 nitems = 0; 63 while ((d = readdir(dirp)) != NULL) { 64 if (select != NULL && !(*select)(d)) 65 continue; /* just selected names */ 66 /* 67 * Make a minimum size copy of the data 68 */ 69 p = (struct dirent *)malloc(DIRSIZ(d)); 70 if (p == NULL) 71 return(-1); 72 p->d_ino = d->d_ino; 73 p->d_reclen = d->d_reclen; 74 p->d_namlen = d->d_namlen; 75 bcopy(d->d_name, p->d_name, p->d_namlen + 1); 76 /* 77 * Check to make sure the array has space left and 78 * realloc the maximum size. 79 */ 80 if (++nitems >= arraysz) { 81 if (fstat(dirp->dd_fd, &stb) < 0) 82 return(-1); /* just might have grown */ 83 arraysz = stb.st_size / 12; 84 names = (struct dirent **)realloc((char *)names, 85 arraysz * sizeof(struct dirent *)); 86 if (names == NULL) 87 return(-1); 88 } 89 names[nitems-1] = p; 90 } 91 closedir(dirp); 92 if (nitems && dcomp != NULL) 93 qsort(names, nitems, sizeof(struct dirent *), dcomp); 94 *namelist = names; 95 return(nitems); 96 } 97 98 /* 99 * Alphabetic order comparison routine for those who want it. 100 */ 101 int 102 alphasort(d1, d2) 103 const void *d1; 104 const void *d2; 105 { 106 return(strcmp((*(struct dirent **)d1)->d_name, 107 (*(struct dirent **)d2)->d_name)); 108 } 109