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 8.3 (Berkeley) 01/02/94"; 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 is the minimum record length which will hold the directory 27 * entry. This requires the amount of space in struct dirent without the 28 * d_name field, plus enough space for the name and a terminating nul byte 29 * (dp->d_namlen + 1), rounded up to a 4 byte boundary. 30 */ 31 #undef DIRSIZ 32 #define DIRSIZ(dp) \ 33 ((sizeof(struct dirent) - sizeof(dp)->d_name) + \ 34 (((dp)->d_namlen + 1 + 3) &~ 3)) 35 36 int 37 scandir(dirname, namelist, select, dcomp) 38 const char *dirname; 39 struct dirent ***namelist; 40 int (*select) __P((struct dirent *)); 41 int (*dcomp) __P((const void *, const void *)); 42 { 43 register struct dirent *d, *p, **names; 44 register size_t nitems; 45 struct stat stb; 46 long arraysz; 47 DIR *dirp; 48 49 if ((dirp = opendir(dirname)) == NULL) 50 return(-1); 51 if (fstat(dirp->dd_fd, &stb) < 0) 52 return(-1); 53 54 /* 55 * estimate the array size by taking the size of the directory file 56 * and dividing it by a multiple of the minimum size entry. 57 */ 58 arraysz = (stb.st_size / 24); 59 names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *)); 60 if (names == NULL) 61 return(-1); 62 63 nitems = 0; 64 while ((d = readdir(dirp)) != NULL) { 65 if (select != NULL && !(*select)(d)) 66 continue; /* just selected names */ 67 /* 68 * Make a minimum size copy of the data 69 */ 70 p = (struct dirent *)malloc(DIRSIZ(d)); 71 if (p == NULL) 72 return(-1); 73 p->d_ino = d->d_ino; 74 p->d_reclen = d->d_reclen; 75 p->d_namlen = d->d_namlen; 76 bcopy(d->d_name, p->d_name, p->d_namlen + 1); 77 /* 78 * Check to make sure the array has space left and 79 * realloc the maximum size. 80 */ 81 if (++nitems >= arraysz) { 82 if (fstat(dirp->dd_fd, &stb) < 0) 83 return(-1); /* just might have grown */ 84 arraysz = stb.st_size / 12; 85 names = (struct dirent **)realloc((char *)names, 86 arraysz * sizeof(struct dirent *)); 87 if (names == NULL) 88 return(-1); 89 } 90 names[nitems-1] = p; 91 } 92 closedir(dirp); 93 if (nitems && dcomp != NULL) 94 qsort(names, nitems, sizeof(struct dirent *), dcomp); 95 *namelist = names; 96 return(nitems); 97 } 98 99 /* 100 * Alphabetic order comparison routine for those who want it. 101 */ 102 int 103 alphasort(d1, d2) 104 const void *d1; 105 const void *d2; 106 { 107 return(strcmp((*(struct dirent **)d1)->d_name, 108 (*(struct dirent **)d2)->d_name)); 109 } 110