Implement command line and environment handling for pcp htop.

.gitignore

@@ -1,5 +1,6 @@
-# the binary:
+# the binaries:
 htop
+pcp-htop
 
 # all object files
 *.o

Makefile.am

@@ -343,8 +343,7 @@ pcp_platform_headers = \
 	zfs/ZfsArcStats.h \
 	zfs/ZfsCompressedArcMeter.h
 
-if HTOP_PCP
-myhtopplatsources = \
+pcp_platform_sources = \
 	pcp/PCPProcess.c \
 	pcp/PCPProcessList.c \
 	pcp/Platform.c \
@@ -353,7 +352,11 @@ myhtopplatsources = \
 	zfs/ZfsArcMeter.c \
 	zfs/ZfsCompressedArcMeter.c
 
+if HTOP_PCP
+myhtopplatprogram = pcp-htop
 myhtopplatheaders = $(pcp_platform_headers)
+myhtopplatsources = $(pcp_platform_sources)
+pcp_htop_SOURCES  = $(htop_SOURCES)
 endif
 
 # Unsupported

pcp-htop.c

@@ -0,0 +1,26 @@
+/*
+htop - pcp-htop.c
+(C) 2004-2011 Hisham H. Muhammad
+(C) 2020-2021 htop dev team
+Released under the GNU GPLv2, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "config.h" // IWYU pragma: keep
+
+#include <pcp/pmapi.h>
+
+#include "CommandLine.h"
+#include "Platform.h"
+
+
+int main(int argc, char** argv) {
+   const char* name = "pcp-htop";
+   pmSetProgname(name);
+
+   /* extract environment variables */
+   opts.flags |= PM_OPTFLAG_ENV_ONLY;
+   pmGetOptions(argc, argv, &opts);
+
+   return CommandLine_run(name, argc, argv);
+}

pcp/PCPProcessList.c

@@ -31,7 +31,7 @@ static int PCPProcessList_computeCPUcount(void) {
 
 static void PCPProcessList_updateCPUcount(PCPProcessList* this) {
    ProcessList* pl = &(this->super);
-   int cpus = PCPProcessList_computeCPUcount();
+   unsigned int cpus = PCPProcessList_computeCPUcount();
    if (cpus == pl->cpuCount)
       return;
 
@@ -40,7 +40,7 @@ static void PCPProcessList_updateCPUcount(PCPProcessList* this) {
    free(this->values);
 
    this->percpu = xCalloc(cpus, sizeof(pmAtomValue *));
-   for (int i = 0; i < cpus; i++)
+   for (unsigned int i = 0; i < cpus; i++)
       this->percpu[i] = xCalloc(CPU_METRIC_COUNT, sizeof(pmAtomValue));
    this->values = xCalloc(cpus, sizeof(pmAtomValue));
 }
@@ -78,7 +78,7 @@ void ProcessList_delete(ProcessList* pl) {
    PCPProcessList* this = (PCPProcessList*) pl;
    ProcessList_done(pl);
    free(this->values);
-   for (int i = 0; i < pl->cpuCount; i++)
+   for (unsigned int i = 0; i < pl->cpuCount; i++)
       free(this->percpu[i]);
    free(this->percpu);
    free(this->cpu);
@@ -716,7 +716,7 @@ static void PCPProcessList_updateHeader(ProcessList* super, const Settings* sett
    PCPProcessList_updateAllCPUTime(this, PCP_CPU_GUEST, CPU_GUEST_TIME);
    PCPProcessList_deriveCPUTime(this->cpu);
 
-   for (int i = 0; i < super->cpuCount; i++)
+   for (unsigned int i = 0; i < super->cpuCount; i++)
       PCPProcessList_backupCPUTime(this->percpu[i]);
    PCPProcessList_updatePerCPUTime(this, PCP_PERCPU_USER, CPU_USER_TIME);
    PCPProcessList_updatePerCPUTime(this, PCP_PERCPU_NICE, CPU_NICE_TIME);
@@ -727,7 +727,7 @@ static void PCPProcessList_updateHeader(ProcessList* super, const Settings* sett
    PCPProcessList_updatePerCPUTime(this, PCP_PERCPU_SOFTIRQ, CPU_SOFTIRQ_TIME);
    PCPProcessList_updatePerCPUTime(this, PCP_PERCPU_STEAL, CPU_STEAL_TIME);
    PCPProcessList_updatePerCPUTime(this, PCP_PERCPU_GUEST, CPU_GUEST_TIME);
-   for (int i = 0; i < super->cpuCount; i++)
+   for (unsigned int i = 0; i < super->cpuCount; i++)
       PCPProcessList_deriveCPUTime(this->percpu[i]);
 
    if (settings->showCPUFrequency)

pcp/Platform.c

@@ -403,14 +403,28 @@ static int Platform_addMetric(Metric id, const char *name) {
    return ++pcp->total;
 }
 
+/* global state from the environment and command line arguments */
+pmOptions opts;
+
 void Platform_init(void) {
-   int sts = pmNewContext(PM_CONTEXT_HOST, "local:");
-   if (sts < 0)
+   const char* host = opts.nhosts > 0 ? opts.hosts[0] : "local:";
+
+   int sts;
+   sts = pmNewContext(PM_CONTEXT_HOST, host);
+   /* with no host requested, fallback to PM_CONTEXT_LOCAL shared libraries */
+   if (sts < 0 && opts.nhosts == 0)
       sts = pmNewContext(PM_CONTEXT_LOCAL, NULL);
    if (sts < 0) {
       fprintf(stderr, "Cannot setup PCP metric source: %s\n", pmErrStr(sts));
       exit(1);
    }
+   /* setup timezones and other general startup preparation completion */
+   pmGetContextOptions(sts, &opts);
+   if (opts.errors) {
+      pmflush();
+      exit(1);
+   }
+
    pcp = xCalloc(1, sizeof(Platform));
    pcp->context = sts;
    pcp->fetch = xCalloc(PCP_METRIC_COUNT, sizeof(pmID));
@@ -795,3 +809,47 @@ void Platform_getBattery(double* level, ACPresence* isOnAC) {
    *level = NAN;
    *isOnAC = AC_ERROR;
 }
+
+void Platform_longOptionsUsage(ATTR_UNUSED const char* name) {
+   printf(
+"   --host=HOSTSPEC              metrics source is PMCD at HOSTSPEC [see PCPIntro(1)]\n"
+"   --hostzone                   set reporting timezone to local time of metrics source\n"
+"   --timezone=TZ                set reporting timezone\n");
+}
+
+bool Platform_getLongOption(int opt, ATTR_UNUSED int argc, char** argv) {
+   /* libpcp export without a header definition */
+   extern void __pmAddOptHost(pmOptions *, char *);
+
+   switch (opt) {
+      case PLATFORM_LONGOPT_HOST:  /* --host=HOSTSPEC */
+         if (argv[optind][0] == '\0')
+            return false;
+	 __pmAddOptHost(&opts, optarg);
+         return true;
+
+      case PLATFORM_LONGOPT_HOSTZONE:  /* --hostzone */
+         if (opts.timezone) {
+            pmprintf("%s: at most one of -Z and -z allowed\n", pmGetProgname());
+            opts.errors++;
+         } else {
+            opts.tzflag = 1;
+         }
+         return true;
+
+      case PLATFORM_LONGOPT_TIMEZONE:  /* --timezone=TZ */
+         if (argv[optind][0] == '\0')
+            return false;
+         if (opts.tzflag) {
+            pmprintf("%s: at most one of -Z and -z allowed\n", pmGetProgname());
+            opts.errors++;
+	 } else {
+            opts.timezone = optarg;
+	 }
+         return true;
+
+      default:
+         break;
+   }
+   return false;
+}

pcp/Platform.h

@@ -87,6 +87,23 @@ void Platform_getHostname(char* buffer, size_t size);
 
 void Platform_getRelease(char** string);
 
+enum {
+   PLATFORM_LONGOPT_HOST = 128,
+   PLATFORM_LONGOPT_TIMEZONE,
+   PLATFORM_LONGOPT_HOSTZONE,
+};
+
+#define PLATFORM_LONG_OPTIONS \
+      {PMLONGOPT_HOST, optional_argument, 0, PLATFORM_LONGOPT_HOST}, \
+      {PMLONGOPT_TIMEZONE, optional_argument, 0, PLATFORM_LONGOPT_TIMEZONE}, \
+      {PMLONGOPT_HOSTZONE, optional_argument, 0, PLATFORM_LONGOPT_HOSTZONE}, \
+
+void Platform_longOptionsUsage(const char* name);
+
+bool Platform_getLongOption(int opt, int argc, char** argv);
+
+extern pmOptions opts;
+
 
 typedef enum Metric_ {
    PCP_CONTROL_THREADS,		/* proc.control.perclient.threads */