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mruby advent cal 2016
** mrb_passwd.c - Passwd class
** Copyright (c) Uchio Kondo 2016
** See Copyright Notice in LICENSE
#include <sys/types.h>
#include <pwd.h>
#include <stdlib.h>
#include <unistd.h>
#include <mruby.h>
#include <mruby/data.h>
#include <mruby/error.h>
#include "mrb_passwd.h"
#define DONE mrb_gc_arena_restore(mrb, 0);
typedef struct mrb_passwd {
struct passwd *pwd;
} mrb_passwd;
static void mrb_passwd_free(mrb_state *mrb, void *p)
mrb_passwd *pwd = (mrb_passwd *)p;
mrb_free(mrb, pwd);
static const struct mrb_data_type mrb_passwd_data_type = {
"mrb_passwd", mrb_passwd_free,
static mrb_value mrb_passwd_init(mrb_state *mrb, mrb_value self)
mrb_passwd *data;
char *name;
struct passwd pwd;
struct passwd *res;
size_t bufsize;
bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
if (bufsize == -1)
bufsize = 16384;
char buf[bufsize];
data = (mrb_passwd *)DATA_PTR(self);
if (data) {
mrb_free(mrb, data);
DATA_TYPE(self) = &mrb_passwd_data_type;
DATA_PTR(self) = NULL;
mrb_get_args(mrb, "z", &name);
data = (mrb_passwd *)mrb_malloc(mrb, sizeof(mrb_passwd));
if(getpwnam_r(name, &pwd, buf, bufsize, &res) < 0)
mrb_sys_fail(mrb, "getpwnam failed");
else if(!res) {
mrb_sys_fail(mrb, "entry not found");
data->pwd = res;
DATA_PTR(self) = data;
return self;
static mrb_value mrb_passwd_uid(mrb_state *mrb, mrb_value self)
mrb_passwd *pwd = DATA_PTR(self);
return mrb_fixnum_value((int)(pwd->pwd->pw_uid));
static mrb_value mrb_passwd_shell(mrb_state *mrb, mrb_value self)
mrb_passwd *pwd = DATA_PTR(self);
return mrb_str_new_cstr(mrb, pwd->pwd->pw_shell);
void mrb_mruby_passwd_example_gem_init(mrb_state *mrb)
struct RClass *passwd;
passwd = mrb_define_class(mrb, "Passwd", mrb->object_class);
mrb_define_method(mrb, passwd, "initialize", mrb_passwd_init, MRB_ARGS_REQ(1));
mrb_define_method(mrb, passwd, "uid", mrb_passwd_uid, MRB_ARGS_NONE());
mrb_define_method(mrb, passwd, "shell", mrb_passwd_shell, MRB_ARGS_NONE());
void mrb_mruby_passwd_example_gem_final(mrb_state *mrb)
## Passwd Test
assert("Passwd#uid") do
t = "root"
assert_equal(0, t.uid)
assert("Passwd#shell") do
t = "root"
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