Merge scandir(3) interface update to stable/8.

MFC r201512:
Modernize scandir(3) and alphasort(3) interfaces according to the IEEE
Std 1003.1-2008.

MFC r201602:
Move scandir(3) and alphasort(3) into XSI namespace.

MFC r201604:
Use thunks to adapt alphasort-like interface to the comparision function
required by qsort() and qsort_r().

MFC r202556 (by ache):
Use strcoll() in opendir() and alphasort(). Remove some comments.

MFC r202572 (by ache):
Revert to using strcmp() for opendir().

MFC r202677 (by ache):
Style.

MFC r202679 (by ache):
Style: rename internal function to opendir_compar().

MFC r202691 (by ache):
For alphasort(3) add reference to strcoll(3).

MFC r202693 (by ache):
Style: reword comment.

include/dirent.h

@@ -93,9 +93,11 @@ typedef	void *	DIR;
 #ifndef _KERNEL
 
 __BEGIN_DECLS
+#if __POSIX_VISIBLE >= 200809 || __XSI_VISIBLE >= 700
+int	 alphasort(const struct dirent **, const struct dirent **);
+#endif
 #if __BSD_VISIBLE
 DIR	*__opendir2(const char *, int);
-int	 alphasort(const void *, const void *);
 int	 getdents(int, char *, int);
 int	 getdirentries(int, char *, int, long *);
 #endif
@@ -107,9 +109,10 @@ struct dirent *
 int	 readdir_r(DIR *, struct dirent *, struct dirent **);
 #endif
 void	 rewinddir(DIR *);
-#if __BSD_VISIBLE
+#if __POSIX_VISIBLE >= 200809 || __XSI_VISIBLE >= 700
 int	 scandir(const char *, struct dirent ***,
-	    int (*)(struct dirent *), int (*)(const void *, const void *));
+	    int (*)(const struct dirent *), int (*)(const struct dirent **,
+	    const struct dirent **));
 #endif
 #if __XSI_VISIBLE
 void	 seekdir(DIR *, long);

lib/libc/gen/opendir.c

@@ -92,6 +92,14 @@ __opendir2(const char *name, int flags)
 	return __opendir_common(fd, name, flags);
 }
 
+static int
+opendir_compar(const void *p1, const void *p2)
+{
+
+	return (strcmp((*(const struct dirent **)p1)->d_name,
+	    (*(const struct dirent **)p2)->d_name));
+}
+
 /*
  * Common routine for opendir(3), __opendir2(3) and fdopendir(3).
  */
@@ -240,7 +248,8 @@ __opendir_common(int fd, const char *name, int flags)
 				/*
 				 * This sort must be stable.
 				 */
-				mergesort(dpv, n, sizeof(*dpv), alphasort);
+				mergesort(dpv, n, sizeof(*dpv),
+				    opendir_compar);
 
 				dpv[n] = NULL;
 				xp = NULL;

lib/libc/gen/scandir.3

@@ -28,7 +28,7 @@
 .\"     @(#)scandir.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd June 4, 1993
+.Dd January 3, 2010
 .Dt SCANDIR 3
 .Os
 .Sh NAME
@@ -38,12 +38,11 @@
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
-.In sys/types.h
 .In dirent.h
 .Ft int
-.Fn scandir "const char *dirname" "struct dirent ***namelist" "int \\*(lp*select\\*(rp\\*(lpstruct dirent *\\*(rp" "int \\*(lp*compar\\*(rp\\*(lpconst void *, const void *\\*(rp"
+.Fn scandir "const char *dirname" "struct dirent ***namelist" "int \\*(lp*select\\*(rp\\*(lpconst struct dirent *\\*(rp" "int \\*(lp*compar\\*(rp\\*(lpconst struct dirent **, const struct dirent **\\*(rp"
 .Ft int
-.Fn alphasort "const void *d1" "const void *d2"
+.Fn alphasort "const struct dirent **d1" "const struct dirent **d2"
 .Sh DESCRIPTION
 The
 .Fn scandir
@@ -82,7 +81,8 @@ The
 function
 is a routine which can be used for the
 .Fa compar
-argument to sort the array alphabetically.
+argument to sort the array alphabetically using
+.Xr strcoll 3 .
 .Pp
 The memory allocated for the array can be deallocated with
 .Xr free 3 ,
@@ -95,7 +95,8 @@ cannot allocate enough memory to hold all the data structures.
 .Xr directory 3 ,
 .Xr malloc 3 ,
 .Xr qsort 3 ,
-.Xr dir 5
+.Xr dir 5 ,
+.Xr strcoll 3
 .Sh HISTORY
 The
 .Fn scandir

lib/libc/gen/scandir.c

@@ -46,6 +46,8 @@ __FBSDID("$FreeBSD$");
 #include <string.h>
 #include "un-namespace.h"
 
+static int alphasort_thunk(void *thunk, const void *p1, const void *p2);
+
 /*
  * The DIRSIZ macro is the minimum record length which will hold the directory
  * entry.  This requires the amount of space in struct dirent without the
@@ -58,11 +60,9 @@ __FBSDID("$FreeBSD$");
 	    (((dp)->d_namlen + 1 + 3) &~ 3))
 
 int
-scandir(dirname, namelist, select, dcomp)
-	const char *dirname;
-	struct dirent ***namelist;
-	int (*select)(struct dirent *);
-	int (*dcomp)(const void *, const void *);
+scandir(const char *dirname, struct dirent ***namelist,
+    int (*select)(const struct dirent *), int (*dcomp)(const struct dirent **,
+	const struct dirent **))
 {
 	struct dirent *d, *p, **names = NULL;
 	size_t nitems = 0;
@@ -111,26 +111,35 @@ scandir(dirname, namelist, select, dcomp)
 	}
 	closedir(dirp);
 	if (nitems && dcomp != NULL)
-		qsort(names, nitems, sizeof(struct dirent *), dcomp);
+		qsort_r(names, nitems, sizeof(struct dirent *),
+		    &dcomp, alphasort_thunk);
 	*namelist = names;
-	return(nitems);
+	return (nitems);
 
 fail:
 	while (nitems > 0)
 		free(names[--nitems]);
 	free(names);
 	closedir(dirp);
-	return -1;
+	return (-1);
 }
 
 /*
  * Alphabetic order comparison routine for those who want it.
+ * POSIX 2008 requires that alphasort() uses strcoll().
  */
 int
-alphasort(d1, d2)
-	const void *d1;
-	const void *d2;
+alphasort(const struct dirent **d1, const struct dirent **d2)
 {
-	return(strcmp((*(struct dirent **)d1)->d_name,
-	    (*(struct dirent **)d2)->d_name));
+
+	return (strcoll((*d1)->d_name, (*d2)->d_name));
+}
+
+static int
+alphasort_thunk(void *thunk, const void *p1, const void *p2)
+{
+	int (*dc)(const struct dirent **, const struct dirent **);
+
+	dc = *(int (**)(const struct dirent **, const struct dirent **))thunk;
+	return (dc((const struct dirent **)p1, (const struct dirent **)p2));
 }

usr.bin/catman/catman.c

@@ -589,9 +589,15 @@ process_section(char *mandir, char *section)
 }
 
 static int
-select_sections(struct dirent *entry)
+select_sections(const struct dirent *entry)
 {
-	return directory_type(entry->d_name) == MAN_SECTION_DIR;
+	char *name;
+	int ret;
+
+	name = strdup(entry->d_name);
+	ret = directory_type(name) == MAN_SECTION_DIR;
+	free(name);
+	return (ret);
 }
 
 /*

usr.bin/makewhatis/makewhatis.c

@@ -879,9 +879,9 @@ process_section(char *section_dir)
  * Returns whether the directory entry is a man page section.
  */
 static int
-select_sections(struct dirent *entry)
+select_sections(const struct dirent *entry)
 {
-	char *p = &entry->d_name[3];
+	const char *p = &entry->d_name[3];
 
 	if (strncmp(entry->d_name, "man", 3) != 0)
 		return 0;

usr.sbin/lpr/common_source/lp.h

@@ -280,7 +280,7 @@ void	 inform(const struct printer *_pp, char *_cf);
 void	 init_printer(struct printer *_pp);
 void	 init_request(struct request *_rp);
 int	 inlist(char *_uname, char *_cfile);
-int	 iscf(struct dirent *_d);
+int	 iscf(const struct dirent *_d);
 void	 ldump(const char *_nfile, const char *_datafile, int _copies);
 void	 lastprinter(void);
 int	 lockchk(struct printer *_pp, char *_slockf);

usr.sbin/lpr/common_source/rmjob.c

@@ -384,7 +384,7 @@ rmremote(const struct printer *pp)
  * Return 1 if the filename begins with 'cf'
  */
 int
-iscf(struct dirent *d)
+iscf(const struct dirent *d)
 {
 	return(d->d_name[0] == 'c' && d->d_name[1] == 'f');
 }