#include <ctype.h>
#include <dirent.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include "common.h"

int threads(int argc, char **argv) {
	FILE *f;
	char buff[256];
	const char *s;
	int i, sum;
	DIR *d;
	struct dirent *e;

	if(argc > 1) {
		if(!strcmp(argv[1], "autoconf")) {
			i = getpid();
			sprintf(buff, "/proc/%d/status", i);
			if(NULL == (f = fopen(buff, "r")))
				return fail("failed to open /proc/$$/status");
			while(fgets(buff, 256, f))
				if(!strncmp(buff, "Threads:", 8)) {
					fclose(f);
					return writeyes();
				}
			fclose(f);
			puts("no");
			return 0;
		}
		if(!strcmp(argv[1], "config")) {
			puts("graph_title Number of threads\n"
				"graph_vlabel number of threads\n"
				"graph_category processes\n"
				"graph_info This graph shows the number of threads.\n"
				"threads.label threads\n"
				"threads.info The current number of threads.");
			return 0;
		}
	}
	if(NULL == (d = opendir("/proc")))
		return fail("cannot open /proc");
	sum = 0;
	while((e = readdir(d))) {
		for(s=e->d_name;*s;++s)
			if(!isdigit(*s))
				break;
		if(*s) /* non-digit found */
			continue;
		snprintf(buff, 256, "/proc/%s/status", e->d_name);
		if(!(f = fopen(buff, "r")))
			continue; /* process has vanished */
		while(fgets(buff, 256, f)) {
			if(strncmp(buff, "Threads:", 8))
				continue;
			if(1 != sscanf(buff+8, "%d", &i)) {
				fclose(f);
				closedir(d);
				return fail("failed to parse "
						"/proc/somepid/status");
			}
			sum += i;
		}
		fclose(f);
	}
	closedir(d);
	printf("threads.value %d\n", sum);
	return 0;
}