smart: importing common.{h,c} from munin-c

The compilation is very easy, a simple `make` should work, as I provided
a convenient `Makefile`

plugins/disk/smart-c/Makefile

@@ -0,0 +1,6 @@
+smart_: smart_.o common.o
+
+.PHONY: clean
+
+clean:
+	rm -f smart_ smart_.o common.o

plugins/disk/smart-c/common.c

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2008-2013 Helmut Grohne <helmut@subdivi.de> - All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2 or v.3.
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "common.h"
+
+extern char **environ;
+
+int writeyes(void)
+{
+	puts("yes");
+	return 0;
+}
+
+int autoconf_check_readable(const char *path)
+{
+	if (0 == access(path, R_OK))
+		return writeyes();
+	else {
+		printf("no (%s is not readable, errno=%d)\n", path, errno);
+		return 0;
+	}
+}
+
+int getenvint(const char *name, int defvalue)
+{
+	const char *value;
+	value = getenv(name);
+	if (value == NULL)
+		return defvalue;
+	return atoi(value);
+}
+
+static
+				    /*@null@ */
+ /*@observer@ */
+const char *getenv_composed(const char *name1, const char *name2)
+{
+	char **p;
+	size_t len1 = strlen(name1), len2 = strlen(name2);
+	for (p = environ; *p; ++p) {
+		if (0 == strncmp(*p, name1, len1) &&
+		    0 == strncmp(len1 + *p, name2, len2) &&
+		    (*p)[len1 + len2] == '=')
+			return len1 + len2 + 1 + *p;
+	}
+	return NULL;
+}
+
+void print_warning(const char *name)
+{
+	const char *p;
+	p = getenv_composed(name, "_warning");
+	if (p == NULL)
+		p = getenv("warning");
+	if (p == NULL)
+		return;
+
+	printf("%s.warning %s\n", name, p);
+}
+
+void print_critical(const char *name)
+{
+	const char *p;
+	p = getenv_composed(name, "_critical");
+	if (p == NULL)
+		p = getenv("critical");
+	if (p == NULL)
+		return;
+
+	printf("%s.critical %s\n", name, p);
+}
+
+void print_warncrit(const char *name)
+{
+	print_warning(name);
+	print_critical(name);
+}
+
+int fail(const char *message)
+{
+	fputs(message, stderr);
+	fputc('\n', stderr);
+	return 1;
+}

plugins/disk/smart-c/common.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2008 Helmut Grohne <helmut@subdivi.de> - All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2 or v.3.
+ */
+#ifndef COMMON_H
+#define COMMON_H
+
+#define PROC_STAT "/proc/stat"
+
+/** Write yes to stdout and return 0. The intended use is give an autoconf
+ * response like "return writeyes();".
+ * @returns a success state to be passed on as the return value from main */
+int writeyes(void);
+
+/** Answer an autoconf request by checking the readability of the given file.
+ */
+int autoconf_check_readable(const char *);
+
+/** Obtain an integer value from the environment. In the absence of the
+ * variable the given defaultvalue is returned.  */
+int getenvint(const char *, int defaultvalue);
+
+/** Print a name.warning line using the "name_warning" or "warning" environment
+ * variables. */
+void print_warning(const char *name);
+
+/** Print a name.critical line using the "name_critical" or "critical"
+ * environment variables. */
+void print_critical(const char *name);
+
+/** Print both name.warning and name.critical lines using environment
+ * variables. */
+void print_warncrit(const char *name);
+
+/** Fail by printing the given message and a newline to stderr.
+ * @returns a failure state to be passed on as the return value from main */
+int fail(const char *message);
+
+#define xisspace(x) isspace((int)(unsigned char) x)
+#define xisdigit(x) isdigit((int)(unsigned char) x)
+
+#endif

plugins/disk/smart-c/smart_.c

@@ -68,7 +68,7 @@ static char getitem(char *input, unsigned char item, char *output)
 	return 0;
 }
 
-int smart(int argc, char **argv)
+int main(int argc, char **argv)
 {
 	char command[50];
 	char output[255];