Add ealloc.c with wrappers for emalloc() and friends

Re-organize util.h as well.

Makefile

@@ -7,6 +7,7 @@ HDR = arg.h config.def.h proc.h reboot.h util.h
 LIB = \
 	util/agetcwd.o        \
 	util/apathmax.o       \
+	util/ealloc.o         \
 	util/eprintf.o        \
 	util/estrtol.o        \
 	util/explicit_bzero.o \

util.h

@@ -4,21 +4,47 @@
 #define UTF8_POINT(c) (((c) & 0xc0) != 0x80)
 #define LEN(x) (sizeof (x) / sizeof *(x))
 
+/* eprintf.c */
 extern char *argv0;
 
+/* agetcwd.c */
 char *agetcwd(void);
+
+/* apathmax.c */
 void apathmax(char **, long *);
-void devtotty(int, int *, int *);
+
+/* eprintf.c */
 void enprintf(int, const char *, ...);
 void eprintf(const char *, ...);
+void weprintf(const char *, ...);
+
+/* ealloc.c */
+void *ecalloc(size_t, size_t);
+void *emalloc(size_t size);
+void *erealloc(void *, size_t);
+char *estrdup(const char *);
+
+/* estrtol.c */
 long estrtol(const char *, int);
+
+/* explicit_bzero.c */
 #undef explicit_bzero
 void explicit_bzero(void *, size_t);
+
+/* putword.c */
 void putword(const char *);
+
+/* recurse.c */
 void recurse(const char *, void (*)(const char *));
+
+/* strlcpy.c */
 #undef strlcat
 size_t strlcat(char *, const char *, size_t);
+
+/* strlcat.c */
 #undef strlcpy
 size_t strlcpy(char *, const char *, size_t);
+
+/* tty.c */
+void devtotty(int, int *, int *);
 char *ttytostr(int, int);
-void weprintf(const char *, ...);

util/ealloc.c

@@ -0,0 +1,46 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdlib.h>
+#include <string.h>
+#include "../util.h"
+
+void *
+ecalloc(size_t nmemb, size_t size)
+{
+	void *p;
+
+	p = calloc(nmemb, size);
+	if (!p)
+		eprintf("calloc: out of memory\n");
+	return p;
+}
+
+void *
+emalloc(size_t size)
+{
+	void *p;
+
+	p = malloc(size);
+	if (!p)
+		eprintf("malloc: out of memory\n");
+	return p;
+}
+
+void *
+erealloc(void *p, size_t size)
+{
+	p = realloc(p, size);
+	if (!p)
+		eprintf("realloc: out of memory\n");
+	return p;
+}
+
+char *
+estrdup(const char *s)
+{
+	char *p;
+
+	p = strdup(s);
+	if (!p)
+		eprintf("strdup: out of memory\n");
+	return p;
+}