# include <stdio.h>

# include <stdlib.h>

# include <fcntl.h>

# include <errno.h>

# include <ctype.h>

# include <sys/ptrace.h>

int main(int argc, char **argv)

{ int ret;

char buf[1024];

int fd;

void *addr = main;

char *name = "/proc/self/mem";

int size = sizeof buf;

int do_attach = 0;

int pid = -1;

if (argc > 1 && strcmp(argv[1], "-attach") == 0) {

do_attach = 1;

argv++, argc--;

}

if (argc > 1) {

name = argv[1];

if (isdigit(*name)) {

pid = atoi(argv[1]);

sprintf(buf, "/proc/%s/mem", argv[1]);

name = buf;

}

argv++, argc--;

}

if (argc > 1) {

addr = (char *) strtoul(argv[1], NULL, 0);

argv++, argc--;

}

if (argc > 1) {

size = atoi(argv[1]);

argv++, argc--;

}

if (do_attach) {

ret = ptrace(PTRACE_ATTACH, pid, 0, 0);

if (ret < 0) {

perror("ptrace(PTRACE_ATTACH)");

exit(1);

}

}

printf("open: %s, offset %p, readlen=%d\n", name, addr, size);

if ((fd = open64(name, O_RDONLY)) < 0) {

perror("name");

exit(1);

}

# if defined(__i386)

/***********************************************/

/* Avoid sign-extension issues in top 2GB */

/* of addr space. */

/***********************************************/

ret = pread64(fd, buf, size, (unsigned long long) (unsigned long) addr);

# else

ret = pread64(fd, buf, size, addr);

# endif

printf("ret=%d\n", ret);

if (ret < 0)

perror("read");

if (do_attach) {

ret = ptrace(PTRACE_DETACH, pid, 0, 0);

if (ret < 0) {

perror("ptrace(PTRACE_DETACH)");

exit(1);

}

}

}