which vs. whereis

index ae4cc03..f689880 100644
@@ -45,10 +45,12 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <dirent.h>
+#include <search.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#include <glob.h>
 
 #include "xalloc.h"
 #include "nls.h"

@@ -130,8 +132,17 @@ static char *srcdirs[] = {
 	0
 };
 
+static struct dirs {
+	char **bindirs; //includes $PATH
+	char **mandirs;
+	char **srcdirs;
+	size_t b_len;
+	size_t m_len;
+	size_t s_len;
+} dirs;
+
 static char sflag = 1, bflag = 1, mflag = 1, uflag;
-static char **Sflag, **Bflag, **Mflag, **pathdir, **pathdir_p;
+static char **Sflag, **Bflag, **Mflag, **pathdir, **dir_list;
 static int Scnt, Bcnt, Mcnt, count, print;
 
 static void __attribute__ ((__noreturn__)) usage(FILE * out)

@@ -260,14 +271,14 @@ static int inpath(const char *str)
 	return 0;
 }
 
-static void fillpath(void)
+static int fillpath(void)
 {
 	char *key=NULL, *tok=NULL, *pathcp, *path = getenv("PATH");
 	int i = 0;
 
 
 	if (!path)
-		return;
+		return 0;
 	pathcp = xstrdup(path);
 
 	for (tok = strtok_r(pathcp, ":", &key); tok;

@@ -278,19 +289,127 @@ static void fillpath(void)
 			continue;
 
 		pathdir = xrealloc(pathdir, (i + 1) * sizeof(char *));
-		pathdir[i++] = xstrdup(tok);
+		pathdir[i++] = canonicalize_file_name(tok);
 	}
 
 	pathdir = xrealloc(pathdir, (i + 1) * sizeof(char *));
 	pathdir[i] = NULL;
 
-	pathdir_p = pathdir;
 	free(pathcp);
+	return i;
+}
+
+static void
+free_b(void)
+{
+	char **bkp = dirs.bindirs;
+	while (*(dirs.bindirs))
+		free(*(dirs.bindirs++));
+	free(bkp);
+}
+
+static void
+free_m(void)
+{
+	char **bkp = dirs.mandirs;
+	while (*(dirs.mandirs))
+		free(*(dirs.mandirs++));
+	free(bkp);
+}
+
+static void
+free_s(void)
+{
+	char **bkp = dirs.srcdirs;
+
+	while (*(dirs.srcdirs))
+		free(*(dirs.srcdirs++));
+	free(bkp);
+}
+
+static void
+free_dirs(void)
+{
+	free_b();
+	free_m();
+	free_s();
+}
+
+static int
+key_cmp(char *key, char **target)
+{
+	return strcmp(key, *target);
 }
 
-static void freepath(void)
+static void
+entry_lookup(char *key, size_t *len, size_t ptr_size)
 {
-	free(pathdir);
+	errno = 0;
+	char *canon;
+  //return if dir in key doesn't exist
+	if (((canon = canonicalize_file_name(key)) == NULL) && errno == ENOENT)
+		return;
+
+	if (!(*len) || !lfind(canon, dir_list, len, ptr_size,
+		(__compar_fn_t) key_cmp)) {
+		dir_list = xrealloc(dir_list, (*len + 1) * ptr_size);
+		dir_list[(*len)++] = canon;
+	}
+	else
+		free(canon);
+}
+
+static void
+make_list(void)
+{
+	size_t len, ptr_size=sizeof(char *);
+	char **lists[4]={bindirs, mandirs, srcdirs, NULL};
+	glob_t glob_tree, glob_bkp;
+	int i = 0;
+
+	len = fillpath();
+	dir_list = pathdir;
+	if (len)
+		free(dir_list[len]); //free the last pathdir entry
+
+	while (lists[i]) {
+		while (*lists[i]) {
+			if (!strchr(*lists[i], '*'))
+				entry_lookup(*lists[i]++, &len, ptr_size);
+			else {
+				if (glob(*lists[i]++, GLOB_NOSORT,
+					NULL, &glob_tree) == GLOB_NOMATCH) {
+					globfree(&glob_tree);
+					continue;
+				}
+				glob_bkp = glob_tree;
+
+				while (*glob_tree.gl_pathv)
+					entry_lookup(*glob_tree.gl_pathv++,
+					             &len, ptr_size);
+				globfree(&glob_bkp);
+			}
+		}
+		dir_list = xrealloc(dir_list, (len + 1) * ptr_size);
+		dir_list[len] = NULL;
+
+		switch (i) {
+			case 0:
+				dirs.bindirs = dir_list;
+				dirs.b_len = len;
+				break;
+			case 1:
+				dirs.mandirs = dir_list;
+				dirs.m_len = len;
+				break;
+			case 2:
+				dirs.srcdirs = dir_list;
+				dirs.s_len = len;
+		}
+			len = 0;
+			dir_list = NULL;
+			++i;
+	}
 }
 
 static void

@@ -305,7 +424,7 @@ static void
 looksrc(char *cp)
 {
 	if (Sflag == 0)
-		findv(srcdirs, ARRAY_SIZE(srcdirs)-1, cp);
+		findv(dirs.srcdirs, dirs.s_len, cp);
 	else
 		findv(Sflag, Scnt, cp);
 }

@@ -314,9 +433,7 @@ static void
 lookbin(char *cp)
 {
 	if (Bflag == 0) {
-		findv(bindirs, ARRAY_SIZE(bindirs)-1, cp);
-		while (*pathdir_p)
-			findin(*pathdir_p++, cp);		/* look $PATH */
+		findv(dirs.bindirs, dirs.b_len, cp);
 	 } else
 		findv(Bflag, Bcnt, cp);
 }

@@ -325,7 +442,7 @@ static void
 lookman(char *cp)
 {
 	if (Mflag == 0)
-		findv(mandirs, ARRAY_SIZE(mandirs)-1, cp);
+		findv(dirs.mandirs, dirs.m_len, cp);
 	else
 		findv(Mflag, Mcnt, cp);
 }

@@ -354,6 +471,7 @@ print_again(char *cp)
 {
 	if (print)
 		printf("%s:", cp);
+
 	if (sflag) {
 		looksrc(cp);
 		if (uflag && print == 0 && count != 1) {

@@ -475,12 +593,14 @@ main(int argc, char **argv)
 			}
 			argv++;
 		} else {
-			if (Bcnt == 0 && pathdir == NULL)
-				fillpath();
+			//fill struct dirs with real pathnames from *dirs[] and $PATH
+			if (!pathdir)
+				make_list();
 			lookup(*argv++);
 		}
 	while (--argc > 0);
 
-	freepath();
+	if (pathdir)
+		free_dirs();
 	return EXIT_SUCCESS;
 }