Refactor pgxc_monitor: help option bug and overall review

pgxc_monitor was not printing help even if requested by "--help"
or "-?". This has been reported by Nikhil Sontakke but I did not
use his patch.
Some whitespaces and spelling mistakes in code are corrected.
Documentation had also some mistakes but it is fixed now.
The creation of the psql command used to monitor nodes is made
more readable and now facilitates future extensions.

2 files changed, 95 insertions, 67 deletions

diff --git a/contrib/pgxc_monitor/pgxc_monitor.c b/contrib/pgxc_monitor/pgxc_monitor.c
index bb341f5315..01f046e90a 100644
--- a/contrib/pgxc_monitor/pgxc_monitor.c
+++ b/contrib/pgxc_monitor/pgxc_monitor.c
@@ -12,24 +12,24 @@
  * Options are:
  * -Z nodetype		What node type to monitor, gtm or node.
  *					gtm tests gtm, gtm_standby or gtm_proxy.
- *					node tests coordinator or datanode.
+ *					node tests Coordinator or Datanode.
  * -p port			Port number of the monitored node.
  * -h host			Host name or IP address of the monitored node.
- * -n nodename      Specifies pgxc_monitor node name.   Default is "pgxc_monitor"
- * -q				Run in quiet mode.  Default is quiet mode.
- * -v				Run in verbose mdoe.
- * --help			Prints the help message and exit with 0.
+ * -n nodename      Specifies pgxc_monitor node name. Default is "pgxc_monitor"
+ * -q				Run in quiet mode. Default is quiet mode.
+ * -v				Run in verbose mode.
+ * --help			Prints the help message and exits with 0.
  *
- * When monitoring coordinator or datanode, -p and -h options can be
- * supplied via .pgpass file.   If you use non-default target database name
+ * When monitoring Coordinator or Datanode, -p and -h options can be
+ * supplied via .pgpass file. If you use non-default target database name
  * and username, they must also be supplied by .pgpass file.
  * If password is needed, it must also be supplied by .pgpass file.
  *
- * Monitoring coordinaor and datanode uses system(3) function.  Therefore,
- * you should not use set-userid bit or set-groupid bit.   Also, because
+ * Monitoring Coordinator and Datanode uses system(3) function.  Therefore,
+ * you should not use set-userid bit or set-groupid bit. Also, because
  * this uses psql command, psql must be in your PATH.
  *
- * When testing coordinator/datanode, you must setup .pgpass file if you
+ * When testing Coordinator/Datanode, you must setup .pgpass file if you
  * need to supply password, as well as non-default database name and username.
  *
  * If invalid parameters are given, error message will be printed even if
@@ -45,38 +45,45 @@
 #include <stdlib.h>
 #include <getopt.h>
 
-/*
- * GTM_Proxy and Datanode are for future extension.
- */
+/* Define all the node types */
 typedef enum
 {
-	None = 0,
-	GTM,
-	GTM_Proxy,
-	Coordinator,
-	Datanode
+	NONE = 0,
+	GTM,	/* GTM or GTM-proxy */
+	NODE	/* Coordinator or Datanode */
 } nodetype_t;
 
 static char 	*progname;
-static nodetype_t nodetype = None;
-static char		*port = NULL;
-static char		*host = NULL;
-static char		*nodename = NULL;
-static int 		verbose = 0;
 
 #define Free(x) do{if((x)) free((x)); x = NULL;} while(0)
 
 static void usage(void);
-static int do_gtm_ping(char *host, char *node, nodetype_t nodetype);
-static int do_node_ping(char *host, char *node);
-
+static int do_gtm_ping(char *host, char *node, nodetype_t nodetype, char *nodename, bool verbose);
+static int do_node_ping(char *host, char *node, bool verbose);
 
-int main (int ac, char *av[])
+int
+main(int ac, char *av[])
 {
 	int opt;
+	nodetype_t	nodetype = NONE;
+	char	   *port = NULL;
+	char	   *host = NULL;
+	char	   *nodename = NULL;
+	bool		verbose = false;
 
 	progname = strdup(av[0]);
 
+	/* Print help if necessary */
+	if (ac > 1)
+	{
+		if (strcmp(av[1], "--help") == 0 || strcmp(av[1], "-?") == 0)
+		{
+			usage();
+			exit(0);
+		}
+	}
+
+	/* Scan options */
 	while ((opt = getopt(ac, av, "Z:h:n:p:qv")) != -1)
 	{
 		switch(opt)
@@ -85,7 +92,7 @@ int main (int ac, char *av[])
 				if (strcmp(optarg, "gtm") == 0)
 					nodetype = GTM;
 				else if (strcmp(optarg, "node") == 0)
-					nodetype = Coordinator;
+					nodetype = NODE;
 				else
 				{
 					fprintf(stderr, "%s: invalid -Z option value.\n", progname);
@@ -105,43 +112,49 @@ int main (int ac, char *av[])
 				port = strdup(optarg);
 				break;
 			case 'q':
-				verbose = 0;
+				verbose = false;
 				break;
 			case 'v':
-				verbose = 1;
+				verbose = true;
 				break;
 			default:
 				fprintf(stderr, "%s: unknow option %c.\n", progname, opt);
 				exit(3);
 		}
 	}
-	if (nodetype == None)
+
+	/* If no types are defined, well there is nothing to be done */
+	if (nodetype == NONE)
 	{
 		fprintf(stderr, "%s: -Z option is missing, it is mandatory.\n", progname);
 		usage();
 		exit(3);
 	}
+
 	switch(nodetype)
 	{
 		case GTM:
-		case GTM_Proxy:
-			exit(do_gtm_ping(host, port, nodetype));
-		case Coordinator:
-		case Datanode:
-			exit(do_node_ping(host, port));
-		case None:
+			exit(do_gtm_ping(host, port, nodetype, nodename, verbose));
+		case NODE:
+			exit(do_node_ping(host, port, verbose));
+		case NONE:
 		default:
 			break;
 	}
-	fprintf(stderr, "%s: inernal error.\n", progname);
+
+	/* Should not happen */
+	fprintf(stderr, "%s: internal error.\n", progname);
 	exit(3);
 }
 
-static int do_gtm_ping(char *host, char* port, nodetype_t nodetype)
+/*
+ * Ping a given GTM or GTM-proxy
+ */
+static int do_gtm_ping(char *host, char* port, nodetype_t nodetype, char *nodename, bool verbose)
 {
 	char connect_str[256];
 	GTM_Conn *conn;
-	
+
 	if (host == NULL)
 	{
 		fprintf(stderr, "%s: -h is mandatory for -Z gtm or -Z gtm_proxy\n", progname);
@@ -152,7 +165,7 @@ static int do_gtm_ping(char *host, char* port, nodetype_t nodetype)
 		fprintf(stderr, "%s: -p is mandatory for -Z gtm or -Z gtm_proxy\n", progname);
 		exit(3);
 	}
-	sprintf(connect_str, "host=%s port=%s node_name=%s remote_type=%d postmaster=0", 
+	sprintf(connect_str, "host=%s port=%s node_name=%s remote_type=%d postmaster=0",
 			host, port, nodename ? nodename : "pgxc_monitor", GTM_NODE_COORDINATOR);
 	if ((conn = PQconnectGTM(connect_str)) == NULL)
 	{
@@ -163,10 +176,13 @@ static int do_gtm_ping(char *host, char* port, nodetype_t nodetype)
 	GTMPQfinish(conn);
 	if (verbose)
 		printf("Running\n");
-	return(0);
+	return 0;
 }
 
-static int do_node_ping(char *host, char *node)
+/*
+ * Ping a given node
+ */
+static int do_node_ping(char *host, char *port, bool verbose)
 {
 	int rc;
 	int exitStatus;
@@ -175,14 +191,20 @@ static int do_node_ping(char *host, char *node)
 	char *verbose_out = "";
 	char *out = verbose ? verbose_out : quiet_out;
 
-	if (host && node)
-		sprintf(command_line, "psql -h %s -p %s -w -q -c \"select 1 a\" %s", host, node, out);
-	else if (host)
-		sprintf(command_line, "psql -h %s -w -q -c \"select 1 a\" %s", host, out);
-	else if (node)
-		sprintf(command_line, "psql -p %p -w -q -c \"select 1 a\" %s", port, out);
-	else
-		sprintf(command_line, "psql -w -q -c \"select 1 a\" %s", out);
+	/* Build psql command launched to node */
+	sprintf(command_line, "psql -w -q -c \"select 1 a\"");
+
+	/* Then add options if necessary */
+	if (host)
+		sprintf(command_line, "%s -h %s", command_line, host);
+	if (port)
+		sprintf(command_line, "%s -p %s", command_line, port);
+
+	/* Add database name, here default database, postgres, is used */
+	sprintf(command_line, "%s postgres", command_line);
+	sprintf(command_line, "%s %s", command_line, out);
+
+	/* Launch the command and output result if necessary */
 	rc = system(command_line);
 	exitStatus = WEXITSTATUS(rc);
 	if (verbose)
@@ -192,20 +214,26 @@ static int do_node_ping(char *host, char *node)
 		else
 			printf("Not running\n");
 	}
-	
-	return(exitStatus);
+
+	return exitStatus;
 }
 
+/*
+ * Show help information
+ */
 static void usage(void)
 {
 	printf("pgxc_monitor -Z nodetype -p port -h host\n\n");
 	printf("Options are:\n");
 	printf("    -Z nodetype	    What node type to monitor, gtm, gtm_proxy,\n");
 	printf("                    coordinator, or datanode.\n");
-	printf("    -h host         Host name or IP address of the monitored node.  Mandatory for -Z gtm or -Z gtm_proxy\n");
-	printf("    -n nodename     Nodename of this pgxc_monitor.   Only for -Z gtm or -Z gtm_proxy.  Default is pgxc_monitor\n");
-	printf("    -p port         Port number of the monitored node.  Mandatory for -Z gtm or -Z gtm_proxy\n");
+	printf("    -h host         Host name or IP address of the monitored node.\n");
+	printf("                    Mandatory for -Z gtm or -Z gtm_proxy\n");
+	printf("    -n nodename     Nodename of this pgxc_monitor.\n");
+	printf("                    Only for -Z gtm or -Z gtm_proxy. Default is pgxc_monitor\n");
+	printf("                    This identifies what is the name of component connecting to GTM.");
+	printf("    -p port         Port number of the monitored node. Mandatory for -Z gtm or -Z gtm_proxy\n");
 	printf("    -q              Quiet mode.\n");
 	printf("    -v              Verbose mode.\n");
-	printf("    --help          Prints the help message and exit with 0.\n");
+	printf("    --help          Prints the help message and exits with 0.\n");
 }
diff --git a/doc-xc/src/sgml/pgxcmonitor.sgmlin b/doc-xc/src/sgml/pgxcmonitor.sgmlin
index a9dc64612e..eac36d4d8e 100644
--- a/doc-xc/src/sgml/pgxcmonitor.sgmlin
+++ b/doc-xc/src/sgml/pgxcmonitor.sgmlin
@@ -4,8 +4,8 @@
 
 <title>pgxc_monitor</title>
 
- <indexterm zone="pgxcclean">
-  <primary>pgxc_monitorn</primary>
+ <indexterm zone="pgxcmonitor">
+  <primary>pgxc_monitor</primary>
  </indexterm>
 
  <sect2>
@@ -20,7 +20,7 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
     </para>
 
     <para>
-     <application>pgxc_clean</application> is Postgres-XC utility to test if
+     <application>pgxc_monitor</application> is a <productname>Postgres-XC</> utility to test if
      the target node is running.
     </para>
 
@@ -47,8 +47,8 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
       <term><option>-Z <replaceable class="parameter">nodetype</replaceable></option></term>
       <listitem>
       <para>
-       Type of node to test.   Specify gtm for gtm and gtm_proxy.
-       Specify node for coordinator and datanode.
+       Type of node type to test. Specify gtm as <replaceable>nodetype</replaceable> for gtm and gtm_proxy.
+       Specify node as <replaceable>nodeopt</replaceable> for a Coordinator or a Datanode.
       </para>
       </listitem>
     </varlistentry>
@@ -66,7 +66,7 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
       <term><option>-n <replaceable class="parameter">nodename</replaceable></></term>
       <listitem>
       <para>
-      Nodename to use when testing gtm or gtm_proxy.
+      Node name to use when testing gtm or gtm_proxy.
       Default value is <literal>pgxc_monitor</literal>.
       </para>
       </listitem>
@@ -85,7 +85,7 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
       <term><option>-q</></term>
       <listitem>
       <para>
-       Surpress messages as much as possible.
+       Quiet mode. Supress messages as much as possible.
       </para>
       </listitem>
     </varlistentry>
@@ -94,7 +94,7 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
       <term><option>-v</></term>
       <listitem>
       <para>
-       Prints as many messages as possible.
+       Verbose mode. Prints as many messages as possible.
       </para>
       </listitem>
     </varlistentry>
@@ -116,7 +116,7 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
   <title>Options</title>
 
   <para>
-   When monitoring coordinator or datanode, <option>-p</option> and
+   When monitoring Coordinator or Datanode, <option>-p</option> and
    <option>-h</option> options can be supplied using
    <literal>.pgpass</literal> file.
    If you use non-default target database name, and username, as well as
@@ -128,7 +128,7 @@ pgxc_monitor <optional> <replaceable>option</> </optional>
    <option>.pgpass</option> file too.
   </para>
   <para>
-   Monitoring coordinaor and datanode uses system(3) function.  
+   Monitoring Coordinator and Datanode uses system(3) function.  
    Therefore,you should not use set-userid bit or set-groupid bit.
    Also, because this uses psql command, psql must be in your PATH.
   </para>