Monitor de consumo de memoria para una lista de PIDs

monitor.c

/*
 * monitor
 * Angel Rodolfo Pérez Canseco(ikcaro)
 * Monitor de consumo de memoria, calculo de memoria basado en pmap
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct {
	int pid;
	char name[250];
	
	unsigned long ssh;
	unsigned long sro;
	unsigned long swr;
	unsigned long stm;
	
	unsigned long csh;
	unsigned long cro;
	unsigned long cwr;
	unsigned long ctm;
} PID;

int first = 1;
PID list[100];

int status_info(PID *p)
{
	char buff[300];
	FILE *fd = NULL;
	
	sprintf(buff, "/proc/%d/status", p->pid);
	fd = fopen(buff, "r");
	if (fd == NULL)
		return 0;
	
	fscanf(fd, "Name: %s\n", p->name);
	
	fclose(fd);
}

int maps_info(PID *p)
{
	FILE *fd = NULL;
	char buff[300];
	unsigned start, end, diff;
	char flags[50];
	
	sprintf(buff, "/proc/%d/maps", p->pid);
	fd = fopen(buff, "r");
	if (fd == NULL) {
		printf("%05d => No existe el proceso\n", p->pid);
		return 0;
	}
	
	p->csh = 0;
	p->cwr = 0;
	p->cro = 0;
	p->ctm = 0;
	
	while (fgets(buff, 300, fd) != NULL) {
		sscanf(buff, "%x-%x %s", &start, &end, flags);
		
		diff = end - start;
		if (flags[3] == 's')
			p->csh += diff;
			
		if (flags[3] == 'p') {
			flags[3] = '-';
			if (flags[1] == 'w')
				p->cwr += diff;
			else
				p->cro += diff;
		}
	}
	
	p->ctm = p->csh + p->cwr + p->cro;
	
	if (first) {
		p->ssh = p->csh;
		p->swr = p->cwr;
		p->sro = p->cro;
		p->stm = p->ctm;
	}

	printf(
		"%05d %-15s %-10d %-10d %-10d %-10d %-10d %-10d %-10d %-10d\n",
		p->pid,
		p->name,
		p->csh >> 10,
		(p->csh - p->ssh) >> 10,
		p->cro >> 10,
		(p->cro - p->sro) >> 10,
		p->cwr >> 10,
		(p->cwr - p->swr) >> 10,
		p->ctm >> 10,
		(p->ctm - p->stm) >> 10
	);
	
	fclose(fd);
}

int main(int argc, char *argv[])
{
	int i;
	
	memset(&list, 0, sizeof(list));
	
	for (i = 1; i < argc; i++)
		list[i - 1].pid = atoi(argv[i]);
	
	while (1) {
		system("clear");
		printf("%-5s %-15s %-10s %-10s %-10s %-10s %-10s %-10s %-10s %-10s\n", 
			"PID",
			"COMM",
			"SHARED",
			"DSHARED",
			"READ",
			"DREAD",
			"WRITE",
			"DWRITE",
			"TOTAL",
			"DTOTAL"
		);
		
		for (i = 0; i < argc - 1; i++) {
			status_info(&list[i]);
			maps_info(&list[i]);
		}
		
		first = 0;
		sleep(1);
	}
	
	return 0;	
}