getconf.c

UNIX下SH的实现源码

  { "SEM_NSEMS_MAX",		SYSCONF,	_SC_SEM_NSEMS_MAX	},
#endif
#if defined (_SC_SEM_VALUE_MAX)
  { "SEM_VALUE_MAX",		SYSCONF,	_SC_SEM_VALUE_MAX	},
#endif
#if defined (_SC_SIGQUEUE_MAX)
  { "SIGQUEUE_MAX",		SYSCONF,	_SC_SIGQUEUE_MAX	},
#endif
#if defined (_SC_TIMER_MAX)
  { "TIMER_MAX",		SYSCONF,	_SC_TIMER_MAX		},
#endif

#if defined (_SC_LOGIN_NAME_MAX)
  { "LOGIN_NAME_MAX",		SYSCONF,	_SC_LOGIN_NAME_MAX	},
#endif
#if defined (_SC_LOGNAME_MAX)
  { "LOGNAME_MAX",		SYSCONF,	_SC_LOGNAME_MAX		},
#endif
#if defined (_SC_TTY_NAME_MAX)
  { "TTY_NAME_MAX",		SYSCONF,	_SC_TTY_NAME_MAX	},
#endif

#if defined (_SC_THREAD_DESTRUCTOR_ITERATIONS)
  { "PTHREAD_DESTRUCTOR_ITERATIONS", SYSCONF,	_SC_THREAD_DESTRUCTOR_ITERATIONS },
#endif
#if defined (_SC_THREAD_KEYS_MAX)
  { "PTHREAD_KEYS_MAX",		SYSCONF,	_SC_THREAD_KEYS_MAX },
#endif
#if defined (_SC_THREAD_STACK_MIN)
  { "PTHREAD_STACK_MIN",	SYSCONF,	_SC_THREAD_STACK_MIN },
#endif
#if defined (_SC_THREAD_THREADS_MAX)
  { "PTHREAD_THREADS_MAX",	SYSCONF,	_SC_THREAD_THREADS_MAX },
#endif

  /* XPG 4.2 Optional Facility Configuration Values */
#if defined (_SC_XOPEN_UNIX)
  { "_XOPEN_UNIX",		SYSCONF,	_SC_XOPEN_UNIX		},
  { "_XOPEN_CRYPT",		SYSCONF,	_SC_XOPEN_CRYPT		},
  { "_XOPEN_ENH_I18N",		SYSCONF,	_SC_XOPEN_ENH_I18N	},
  { "_XOPEN_SHM",		SYSCONF,	_SC_XOPEN_SHM		},
  { "_XOPEN_VERSION",		SYSCONF,	_SC_XOPEN_VERSION	},
#  if defined (_SC_XOPEN_XCU_VERSION)
  { "_XOPEN_XCU_VERSION",	SYSCONF,	_SC_XOPEN_XCU_VERSION	},
#  endif
#endif
#if defined (_SC_XOPEN_REALTIME)
  { "_XOPEN_REALTIME",		SYSCONF,	_SC_XOPEN_REALTIME	},
  { "_XOPEN_REALTIME_THREADS",	SYSCONF,	_SC_XOPEN_REALTIME_THREADS },
#endif
#if defined (_SC_XOPEN_LEGACY)
  { "_XOPEN_LEGACY",		SYSCONF,	_SC_XOPEN_LEGACY	},
#endif /* _SC_XOPEN_LEGACY */

  /* Single UNIX Specification version 2 Optional Facility Configuration Values */
#if defined (_SC_XBS5_ILP32_OFF32)
  { "_XBS5_ILP32_OFF32",	SYSCONF,	_SC_XBS5_ILP32_OFF32	},
  { "_XBS5_ILP32_OFFBIG",	SYSCONF,	_SC_XBS5_ILP32_OFFBIG	},
  { "_XBS5_LP64_OFF64",		SYSCONF,	_SC_XBS5_LP64_OFF64	},
  { "_XBS5_LPBIG_OFFBIG",	SYSCONF,	_SC_XBS5_LPBIG_OFFBIG	},
#endif /* _SC_XBS5_ILP32_OFF32 */

  /* POSIX.1 Configurable Pathname Values */
  { "LINK_MAX",			PATHCONF,	_PC_LINK_MAX		},
  { "MAX_CANON",		PATHCONF,	_PC_MAX_CANON		},
  { "MAX_INPUT",		PATHCONF,	_PC_MAX_INPUT		},
  { "NAME_MAX",			PATHCONF,	_PC_NAME_MAX		},
  { "PATH_MAX",			PATHCONF,	_PC_PATH_MAX		},
  { "PIPE_BUF",			PATHCONF,	_PC_PIPE_BUF		},
  { "_POSIX_CHOWN_RESTRICTED",	PATHCONF,	_PC_CHOWN_RESTRICTED	},
  { "_POSIX_NO_TRUNC",		PATHCONF,	_PC_NO_TRUNC		},
  { "_POSIX_VDISABLE",		PATHCONF,	_PC_VDISABLE		},

  /* XPG 4.2 Configurable Pathname Values */
#if defined (_PC_FILESIZEBITS)
  { "FILESIZEBITS",		PATHCONF,	_PC_FILESIZEBITS },
#endif
#if defined (_PC_ASYNC_IO)
  { "_POSIX_ASYNC_IO",		PATHCONF,	_PC_ASYNC_IO },
#endif
#if defined (_PC_PRIO_IO)
  { "_POSIX_PRIO_IO",		PATHCONF,	_PC_PRIO_IO },
#endif
#if defined (_PC_SYNC_IO)
  { "_POSIX_SYNC_IO",		PATHCONF,	_PC_SYNC_IO },
#endif

  { NULL }
};

static int num_getconf_variables = sizeof(conf_table) / sizeof(struct conf_variable) - 1;

extern char *this_command_name;
extern char *xmalloc ();
extern char **make_builtin_argv ();

static void getconf_help ();
static int getconf_print ();
static int getconf_one ();
static int getconf_all ();

int
getconf_builtin (list)
     WORD_LIST *list;
{
  int c, r, opt, aflag;
  char **v;

  aflag = 0;
  reset_internal_getopt();
  while ((opt = internal_getopt (list, "ah")) != -1) {
  	switch (opt) {
  	case 'a':
  		aflag = 1;
  		break;
  	case 'h':
  		getconf_help();
  		return(EXECUTION_SUCCESS);
  	default:
  		builtin_usage();
  		return(EX_USAGE);
  	}
  }
 
  list = loptend;
  if ((aflag == 0 && list == 0) || (aflag && list) || list_length(list) > 2) {
  	builtin_usage();
  	return(EX_USAGE);
  }

  r = aflag ? getconf_all() : getconf_one(list);

  return r;
}

static void
getconf_help()
{
	const struct conf_variable *cp;
	register int i, column;

	builtin_usage();
	printf("Acceptable variable names are:\n");
	for (cp = conf_table; cp->name != NULL; cp++) {
		if (cp->type == PATHCONF)
			printf("%s pathname\n", cp->name);
		else
			printf("%s\n", cp->name);
	}
}

static int
getconf_print(cp, vpath, all)
struct conf_variable *cp;
char *vpath;
int all;
{
	long val;
	char *sval;
	size_t slen;

	switch (cp->type) {
	case CONSTANT:
		printf("%ld\n", cp->value);
		break;

	case CONFSTR:
		errno = 0;
		slen = confstr (cp->value, (char *) 0, (size_t) 0);
		if (slen == 0) {
			if (errno != 0) {
				if (all)
					printf ("getconf: %s\n", strerror(errno));
				else
					builtin_error ("%s", strerror(errno));
			} else
				printf ("undefined\n");
			return (EXECUTION_FAILURE);
		}
		sval = xmalloc(slen);

		confstr(cp->value, sval, slen);
		printf("%s\n", sval);
		free(sval);
		break;

	case SYSCONF:
		errno = 0;
		if ((val = sysconf(cp->value)) == -1) {
			if (errno != 0) {
				if (all)
					printf("getconf: %s\n", strerror (errno));
				else
					builtin_error ("%s", strerror (errno));
				return (EXECUTION_FAILURE);
			}

			printf ("undefined\n");
		} else {
			printf("%ld\n", val);
		}
		break;

	case PATHCONF:
		errno = 0;
		if ((val = pathconf(vpath, cp->value)) == -1) {
			if (errno != 0) {
				if (all)
					printf("getconf: %s: %s\n", vpath, strerror (errno));
				else
					builtin_error ("%s: %s", vpath, strerror (errno));
				return (EXECUTION_FAILURE);
			}

			printf ("undefined\n");
		} else {
			printf ("%ld\n", val);
		}
		break;
	}

	return (ferror(stdout) ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
}

static int
getconf_all()
{
	const struct conf_variable *cp;
	int ret;

	ret = EXECUTION_SUCCESS;
	for (cp = conf_table; cp->name != NULL; cp++) {
		printf("%-35s", cp->name);
		if (getconf_print(cp, ".", 1) == EXECUTION_FAILURE)
			ret = EXECUTION_FAILURE;
	}
	return ret;
}

static int
getconf_one(list)
	WORD_LIST *list;
{
	const struct conf_variable *cp;
	char *vname, *vpath;

	vname = list->word->word;
	vpath = (list->next && list->next->word) ? list->next->word->word
						 : (char *)NULL;

	for (cp = conf_table; cp->name != NULL; cp++) {
		if (strcmp(vname, cp->name) == 0)
			break;
	}
	if (cp->name == NULL) {
		builtin_error ("%s: unknown variable", vname);
		return (EXECUTION_FAILURE);
	}

	if (cp->type == PATHCONF) {
		if (list->next == 0) {
			builtin_usage();
			return(EX_USAGE);
		}
	} else {
		if (list->next) {
			builtin_usage();
			return(EX_USAGE);
		}
	}

	return (getconf_print(cp, vpath, 0));
}

static char *getconf_doc[] = {
	"getconf writes the current value of a configurable system limit or",
	"option variable to the standard output.",
	(char *)NULL
};

struct builtin getconf_struct = {
	"getconf",
	getconf_builtin,
	BUILTIN_ENABLED,
	getconf_doc,
	"getconf -a or getconf -h or getconf sysvar or getconf pathvar pathname",
	0
};