/* * scandir, alphasort - scan a directory * * implementation for systems that do not have it in libc */ #include "config.h" #ifndef HAVE_SCANDIR #include <sys/types.h> #include <dirent.h> #include <stdlib.h> #include <stddef.h> #include <string.h> /* * convenience helper function for scandir's |compar()| function: * sort directory entries using strcoll(3) */ int alphasort(const void *_a, const void *_b) { struct dirent **a = (struct dirent **)_a; struct dirent **b = (struct dirent **)_b; return strcoll((*a)->d_name, (*b)->d_name); } #define strverscmp(a,b) strcoll(a,b) /* for now */ /* * convenience helper function for scandir's |compar()| function: * sort directory entries using GNU |strverscmp()| */ int versionsort(const void *_a, const void *_b) { struct dirent **a = (struct dirent **)_a; struct dirent **b = (struct dirent **)_b; return strverscmp((*a)->d_name, (*b)->d_name); } /* * The scandir() function reads the directory dirname and builds an * array of pointers to directory entries using malloc(3). It returns * the number of entries in the array. A pointer to the array of * directory entries is stored in the location referenced by namelist. * * The select parameter is a pointer to a user supplied subroutine * which is called by scandir() to select which entries are to be * included in the array. The select routine is passed a pointer to * a directory entry and should return a non-zero value if the * directory entry is to be included in the array. If select is null, * then all the directory entries will be included. * * The compar parameter is a pointer to a user supplied subroutine * which is passed to qsort(3) to sort the completed array. If this * pointer is null, the array is not sorted. */ int scandir(const char *dirname, struct dirent ***ret_namelist, int (*select)(const struct dirent *), int (*compar)(const struct dirent **, const struct dirent **)) { int i, len; int used, allocated; DIR *dir; struct dirent *ent, *ent2; struct dirent **namelist = NULL; if ((dir = opendir(dirname)) == NULL) return -1; used = 0; allocated = 2; namelist = malloc(allocated * sizeof(struct dirent *)); if (!namelist) goto error; while ((ent = readdir(dir)) != NULL) { if (select != NULL && !select(ent)) continue; /* duplicate struct direct for this entry */ len = offsetof(struct dirent, d_name) + strlen(ent->d_name) + 1; if ((ent2 = malloc(len)) == NULL) goto error; if (used >= allocated) { allocated *= 2; namelist = realloc(namelist, allocated * sizeof(struct dirent *)); if (!namelist) goto error; } memcpy(ent2, ent, len); namelist[used++] = ent2; } closedir(dir); if (compar) qsort(namelist, used, sizeof(struct dirent *), (int (*)(const void *, const void *)) compar); *ret_namelist = namelist; return used; error: closedir(dir); if (namelist) { for (i = 0; i < used; i++) free(namelist[i]); free(namelist); } return -1; } #endif #if STANDALONE_MAIN int main(int argc, char **argv) { struct dirent **namelist; int i, n; n = scandir("/etc", &namelist, NULL, alphasort); for (i = 0; i < n; i++) printf("%s\n", namelist[i]->d_name); } #endif