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

#ifndef REOPEN
#define REOPEN	0
#endif

int main(int argc, char **argv)
{
	int bufsize = 1024;
	char *buf = NULL;
	int bufused;
	int got;
	int fd = -1;
	char path[100];

	if (argc <= 1)
		strcpy(path, "/proc/self/maps");
	else
		sprintf(path, "/proc/%s/maps", argv[1]);

  again:
	if (fd == -1)
		fd = open(path, O_RDONLY);

	if (fd == -1) {
		perror("open");
		exit(1);
	}

	if (lseek(fd, 0, SEEK_SET) == -1) {
		perror("lseek");
		exit(1);
	}
	bufused = 0;
	if (buf == NULL)
		buf = malloc(bufsize);

	do {
		int want = bufsize - bufused;
		got = read(fd, &buf[bufused],
			       want > 4000 ? 4000 : want); /* work around other bug */
		if (got < 0) {
			perror("read");
			exit(1);
		}
		bufused += got;
	} while(bufused < bufsize && got != 0);

	if (bufused == bufsize) {
		free(buf);
		buf = NULL;
		bufsize *= 2;
		if (REOPEN) {
			/* reopen */
			close(fd);
			fd = -1;
		}
		goto again;
	}
	close(fd);

	write(1, buf, bufused);

	return 0;
}