lib/: Call strchrnul(3) instead of open-coding it

Performance tests made in 2007 are obsolete.  We should assume libc is
reasonably fast today (otherwise, report a bug to libc).

$ git blame -- lib/sgetgrent.c | grep strchr
45c6603cc (nekral-guest      2007-10-07 11:44:02 +0000  30)  *	WARNING: I profiled this once with and without strchr() calls
6f88bcf58 (nekral-guest      2008-05-26 08:31:14 +0000  97) 		cp = strchr (cp, ':');

Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/sgetgrent.c

@@ -14,6 +14,7 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <grp.h>
+#include <string.h>
 
 #include "alloc.h"
 #include "defines.h"
@@ -27,14 +28,11 @@
  *	list() converts the comma-separated list of member names into
  *	an array of character pointers.
  *
- *	WARNING: I profiled this once with and without strchr() calls
- *	and found that using a register variable and an explicit loop
- *	works best.  For large /etc/group files, this is a major win.
- *
  * FINALLY added dynamic allocation.  Still need to fix sgetsgent().
  *  --marekm
  */
-static char **list (char *s)
+static char **
+list(char *s)
 {
 	static char **members = NULL;
 	static size_t size = 0;	/* max members + 1 */
@@ -55,9 +53,7 @@ static char **list (char *s)
 		if (!s || s[0] == '\0')
 			break;
 		members[i++] = s;
-		while (('\0' != *s) && (',' != *s)) {
-			s++;
-		}
+		s = strchrnul(s, ',');
 		if ('\0' != *s) {
 			*s++ = '\0';
 		}

lib/sgetpwent.c

@@ -12,9 +12,11 @@
 #ident "$Id$"
 
 #include <sys/types.h>
-#include "defines.h"
 #include <stdio.h>
 #include <pwd.h>
+#include <string.h>
+
+#include "defines.h"
 #include "prototypes.h"
 #include "shadowlog_internal.h"
 
@@ -32,7 +34,8 @@
  *	performance reasons.  I am going to come up with some conditional
  *	compilation glarp to improve on this in the future.
  */
-struct passwd *sgetpwent (const char *buf)
+struct passwd *
+sgetpwent(const char *buf)
 {
 	static struct passwd pwent;
 	static char pwdbuf[PASSWD_ENTRY_MAX_LENGTH];
@@ -60,9 +63,7 @@ struct passwd *sgetpwent (const char *buf)
 
 	for (cp = pwdbuf, i = 0; (i < NFIELDS) && (NULL != cp); i++) {
 		fields[i] = cp;
-		while (('\0' != *cp) && (':' != *cp)) {
-			cp++;
-		}
+		cp = strchrnul(cp, ':');
 
 		if ('\0' != *cp) {
 			*cp = '\0';

lib/sgetspent.c

@@ -14,17 +14,24 @@
 
 #ident "$Id$"
 
+#include <stdio.h>
 #include <sys/types.h>
+#include <string.h>
+
 #include "prototypes.h"
 #include "shadowlog_internal.h"
 #include "defines.h"
-#include <stdio.h>
+
+
 #define	FIELDS	9
 #define	OFIELDS	5
+
+
 /*
  * sgetspent - convert string in shadow file format to (struct spwd *)
  */
-struct spwd *sgetspent (const char *string)
+struct spwd *
+sgetspent(const char *string)
 {
 	static char spwbuf[PASSWD_ENTRY_MAX_LENGTH];
 	static struct spwd spwd;
@@ -57,9 +64,7 @@ struct spwd *sgetspent (const char *string)
 
 	for (cp = spwbuf, i = 0; ('\0' != *cp) && (i < FIELDS); i++) {
 		fields[i] = cp;
-		while (('\0' != *cp) && (':' != *cp)) {
-			cp++;
-		}
+		cp = strchrnul(cp, ':');
 
 		if ('\0' != *cp) {
 			*cp = '\0';

lib/subordinateio.c

@@ -16,6 +16,7 @@
 #include <pwd.h>
 #include <ctype.h>
 #include <fcntl.h>
+#include <string.h>
 
 #include "alloc.h"
 #include "string/sprintf.h"
@@ -74,7 +75,8 @@ subordinate_free(/*@only@*/void *ent)
  * in @line, or NULL on failure.  Note that the returned value should not
  * be freed by the caller.
  */
-static void *subordinate_parse (const char *line)
+static void *
+subordinate_parse(const char *line)
 {
 	static struct subordinate_range range;
 	static char rangebuf[1024];
@@ -97,9 +99,7 @@ static void *subordinate_parse (const char *line)
 
 	for (cp = rangebuf, i = 0; (i < SUBID_NFIELDS) && (NULL != cp); i++) {
 		fields[i] = cp;
-		while (('\0' != *cp) && (':' != *cp)) {
-			cp++;
-		}
+		cp = strchrnul(cp, ':');
 
 		if ('\0' != *cp) {
 			*cp = '\0';