1 /* scandir.c 4.1 82/12/13 */ 2 /* 3 * Scan the directory dirname calling select to make a list of selected 4 * directory entries then sort using qsort and compare routine dcomp. 5 * Returns the number of entries and a pointer to a list of pointers to 6 * struct direct (through namelist). Returns -1 if there were any errors. 7 */ 8 9 #include <sys/types.h> 10 #include <sys/stat.h> 11 #include <dir.h> 12 13 scandir(dirname, namelist, select, dcomp) 14 char *dirname; 15 struct direct *(*namelist[]); 16 int (*select)(), (*dcomp)(); 17 { 18 register struct direct *d, *p, **names; 19 register int nitems; 20 register char *cp1, *cp2; 21 struct stat stb; 22 long arraysz; 23 DIR *dirp; 24 25 if ((dirp = opendir(dirname)) == NULL) 26 return(-1); 27 if (fstat(dirp->dd_fd, &stb) < 0) 28 return(-1); 29 30 /* 31 * estimate the array size by taking the size of the directory file 32 * and dividing it by a multiple of the minimum size entry. 33 */ 34 arraysz = (stb.st_size / 24); 35 names = (struct direct **)malloc(arraysz * sizeof(struct direct *)); 36 if (names == NULL) 37 return(-1); 38 39 nitems = 0; 40 while ((d = readdir(dirp)) != NULL) { 41 if (select != NULL && !(*select)(d)) 42 continue; /* just selected names */ 43 /* 44 * Make a minimum size copy of the data 45 */ 46 p = (struct direct *)malloc(DIRSIZ(d)); 47 if (p == NULL) 48 return(-1); 49 p->d_ino = d->d_ino; 50 p->d_reclen = d->d_reclen; 51 p->d_namlen = d->d_namlen; 52 for (cp1 = p->d_name, cp2 = d->d_name; *cp1++ = *cp2++; ); 53 /* 54 * Check to make sure the array has space left and 55 * realloc the maximum size. 56 */ 57 if (++nitems >= arraysz) { 58 names = (struct direct **)realloc((char *)names, 59 (stb.st_size/12) * sizeof(struct direct *)); 60 if (names == NULL) 61 return(-1); 62 } 63 names[nitems-1] = p; 64 } 65 closedir(dirp); 66 if (nitems && dcomp != NULL) 67 qsort(names, nitems, sizeof(struct direct *), dcomp); 68 *namelist = names; 69 return(nitems); 70 } 71 72 /* 73 * Alphabetic order comparison routine for those who want it. 74 */ 75 alphasort(d1, d2) 76 struct direct **d1, **d2; 77 { 78 return(strcmp((*d1)->d_name, (*d2)->d_name)); 79 } 80