[thirdparty/util-linux.git] / include / c.h

/*
 * Fundamental C definitions.
 */

#ifndef UTIL_LINUX_C_H
#define UTIL_LINUX_C_H

#include <limits.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include <assert.h>

#ifdef HAVE_ERR_H
# include <err.h>
#endif

#ifdef HAVE_SYS_SYSMACROS_H
# include <sys/sysmacros.h>     /* for major, minor */
#endif

#ifndef LOGIN_NAME_MAX
# define LOGIN_NAME_MAX 256
#endif

#ifndef NAME_MAX
# define NAME_MAX PATH_MAX
#endif

/*
 * __GNUC_PREREQ is deprecated in favour of __has_attribute() and
 * __has_feature(). The __has macros are supported by clang and gcc>=5.
 */
#ifndef __GNUC_PREREQ
# if defined __GNUC__ && defined __GNUC_MINOR__
#  define __GNUC_PREREQ(maj, min) \
	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
# else
#  define __GNUC_PREREQ(maj, min) 0
# endif
#endif

#ifdef __GNUC__

/* &a[0] degrades to a pointer: a different type from an array */
# define __must_be_array(a) \
	UL_BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(__typeof__(a), __typeof__(&a[0])))

# define ignore_result(x) __extension__ ({ \
	__typeof__(x) __dummy __attribute__((__unused__)) = (x); (void) __dummy; \
})

#else /* !__GNUC__ */
# define __must_be_array(a)	0
# define __attribute__(_arg_)
# define ignore_result(x) ((void) (x))
#endif /* !__GNUC__ */

/*
 * It evaluates to 1 if the attribute/feature is supported by the current
 * compilation targed. Fallback for old compilers.
 */
#ifndef __has_attribute
  #define __has_attribute(x) 0
#endif

#ifndef __has_feature
  #define __has_feature(x) 0
#endif

/*
 * Function attributes
 */
#ifndef __ul_alloc_size
# if (__has_attribute(alloc_size) && __has_attribute(warn_unused_result)) || __GNUC_PREREQ (4, 3)
#  define __ul_alloc_size(s) __attribute__((alloc_size(s), warn_unused_result))
# else
#  define __ul_alloc_size(s)
# endif
#endif

#ifndef __ul_calloc_size
# if (__has_attribute(alloc_size) && __has_attribute(warn_unused_result)) || __GNUC_PREREQ (4, 3)
#  define __ul_calloc_size(n, s) __attribute__((alloc_size(n, s), warn_unused_result))
# else
#  define __ul_calloc_size(n, s)
# endif
#endif

#if __has_attribute(returns_nonnull) || __GNUC_PREREQ (4, 9)
# define __ul_returns_nonnull __attribute__((returns_nonnull))
#else
# define __ul_returns_nonnull
#endif

/*
 * Force a compilation error if condition is true, but also produce a
 * result (of value 0 and type size_t), so the expression can be used
 * e.g. in a structure initializer (or wherever else comma expressions
 * aren't permitted).
 */
#define UL_BUILD_BUG_ON_ZERO(e) __extension__ (sizeof(struct { int:-!!(e); }))
#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))

#ifndef ARRAY_SIZE
# define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
#endif

#ifndef PATH_MAX
# define PATH_MAX 4096
#endif

#ifndef TRUE
# define TRUE 1
#endif

#ifndef FALSE
# define FALSE 0
#endif

#ifndef min
# define min(x, y) __extension__ ({		\
	__typeof__(x) _min1 = (x);		\
	__typeof__(y) _min2 = (y);		\
	(void) (&_min1 == &_min2);		\
	_min1 < _min2 ? _min1 : _min2; })
#endif

#ifndef max
# define max(x, y) __extension__ ({		\
	__typeof__(x) _max1 = (x);		\
	__typeof__(y) _max2 = (y);		\
	(void) (&_max1 == &_max2);		\
	_max1 > _max2 ? _max1 : _max2; })
#endif

#ifndef cmp_numbers
# define cmp_numbers(x, y) __extension__ ({	\
	__typeof__(x) _a = (x);			\
	__typeof__(y) _b = (y);			\
	(void) (&_a == &_b);			\
	_a == _b ? 0 : _a > _b ? 1 : -1; })
#endif

#ifndef offsetof
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#endif

/*
 * container_of - cast a member of a structure out to the containing structure
 * @ptr:	the pointer to the member.
 * @type:	the type of the container struct this is embedded in.
 * @member:	the name of the member within the struct.
 */
#ifndef container_of
#define container_of(ptr, type, member) __extension__ ({	\
	const __typeof__( ((type *)0)->member ) *__mptr = (ptr); \
	(type *)( (char *)__mptr - offsetof(type,member) );})
#endif

#ifndef HAVE_PROGRAM_INVOCATION_SHORT_NAME
# ifdef HAVE___PROGNAME
extern char *__progname;
#  define program_invocation_short_name __progname
# else
#  ifdef HAVE_GETEXECNAME
#   define program_invocation_short_name \
		prog_inv_sh_nm_from_file(getexecname(), 0)
#  else
#   define program_invocation_short_name \
		prog_inv_sh_nm_from_file(__FILE__, 1)
#  endif
static char prog_inv_sh_nm_buf[256];
static inline char *
prog_inv_sh_nm_from_file(char *f, char stripext)
{
	char *t;

	if ((t = strrchr(f, '/')) != NULL)
		t++;
	else
		t = f;

	strncpy(prog_inv_sh_nm_buf, t, sizeof(prog_inv_sh_nm_buf) - 1);
	prog_inv_sh_nm_buf[sizeof(prog_inv_sh_nm_buf) - 1] = '\0';

	if (stripext && (t = strrchr(prog_inv_sh_nm_buf, '.')) != NULL)
		*t = '\0';

	return prog_inv_sh_nm_buf;
}
# endif
#endif


#ifndef HAVE_ERR_H
static inline void
errmsg(char doexit, int excode, char adderr, const char *fmt, ...)
{
	fprintf(stderr, "%s: ", program_invocation_short_name);
	if (fmt != NULL) {
		va_list argp;
		va_start(argp, fmt);
		vfprintf(stderr, fmt, argp);
		va_end(argp);
		if (adderr)
			fprintf(stderr, ": ");
	}
	if (adderr)
		fprintf(stderr, "%m");
	fprintf(stderr, "\n");
	if (doexit)
		exit(excode);
}

#ifndef HAVE_ERR
# define err(E, FMT...) errmsg(1, E, 1, FMT)
#endif

#ifndef HAVE_ERRX
# define errx(E, FMT...) errmsg(1, E, 0, FMT)
#endif

#ifndef HAVE_WARN
# define warn(FMT...) errmsg(0, 0, 1, FMT)
#endif

#ifndef HAVE_WARNX
# define warnx(FMT...) errmsg(0, 0, 0, FMT)
#endif
#endif /* !HAVE_ERR_H */


/* Don't use inline function to avoid '#include "nls.h"' in c.h
 */
#define errtryhelp(eval) __extension__ ({ \
	fprintf(stderr, _("Try '%s --help' for more information.\n"), \
			program_invocation_short_name); \
	exit(eval); \
})

/* After failed execvp() */
#define EX_EXEC_FAILED		126	/* Program located, but not usable. */
#define EX_EXEC_ENOENT		127	/* Could not find program to exec.  */
#define errexec(name)	err(errno == ENOENT ? EX_EXEC_ENOENT : EX_EXEC_FAILED, \
			_("failed to execute %s"), name)


static inline __attribute__((const)) int is_power_of_2(unsigned long num)
{
	return (num != 0 && ((num & (num - 1)) == 0));
}

#ifndef HAVE_LOFF_T
typedef int64_t loff_t;
#endif

#if !defined(HAVE_DIRFD) && (!defined(HAVE_DECL_DIRFD) || HAVE_DECL_DIRFD == 0) && defined(HAVE_DIR_DD_FD)
#include <sys/types.h>
#include <dirent.h>
static inline int dirfd(DIR *d)
{
	return d->dd_fd;
}
#endif

/*
 * Fallback defines for old versions of glibc
 */
#include <fcntl.h>

#ifdef O_CLOEXEC
#define UL_CLOEXECSTR	"e"
#else
#define UL_CLOEXECSTR	""
#endif

#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif

#ifdef __FreeBSD_kernel__
#ifndef F_DUPFD_CLOEXEC
#define F_DUPFD_CLOEXEC	17	/* Like F_DUPFD, but FD_CLOEXEC is set */
#endif
#endif


#ifndef AI_ADDRCONFIG
#define AI_ADDRCONFIG 0x0020
#endif

#ifndef IUTF8
#define IUTF8 0040000
#endif

/*
 * MAXHOSTNAMELEN replacement
 */
static inline size_t get_hostname_max(void)
{
	long len = sysconf(_SC_HOST_NAME_MAX);

	if (0 < len)
		return len;

#ifdef MAXHOSTNAMELEN
	return MAXHOSTNAMELEN;
#elif HOST_NAME_MAX
	return HOST_NAME_MAX;
#endif
	return 64;
}

/*
 * The usleep function was marked obsolete in POSIX.1-2001 and was removed
 * in POSIX.1-2008.  It was replaced with nanosleep() that provides more
 * advantages (like no interaction with signals and other timer functions).
 */
#include <time.h>

static inline int xusleep(useconds_t usec)
{
#ifdef HAVE_NANOSLEEP
	struct timespec waittime = {
		.tv_sec   =  usec / 1000000L,
		.tv_nsec  = (usec % 1000000L) * 1000
	};
	return nanosleep(&waittime, NULL);
#elif defined(HAVE_USLEEP)
	return usleep(usec);
#else
# error	"System with usleep() or nanosleep() required!"
#endif
}

/*
 * Constant strings for usage() functions. For more info see
 * Documentation/{howto-usage-function.txt,boilerplate.c}
 */
#define USAGE_HEADER     _("\nUsage:\n")
#define USAGE_OPTIONS    _("\nOptions:\n")
#define USAGE_FUNCTIONS  _("\nFunctions:\n")
#define USAGE_COMMANDS   _("\nCommands:\n")
#define USAGE_COLUMNS    _("\nAvailable output columns:\n")
#define USAGE_SEPARATOR    "\n"

#define USAGE_OPTSTR_HELP     _("display this help")
#define USAGE_OPTSTR_VERSION  _("display version")

#define USAGE_HELP_OPTIONS(marg_dsc) \
		"%-" #marg_dsc "s%s\n" \
		"%-" #marg_dsc "s%s\n" \
		, " -h, --help",    USAGE_OPTSTR_HELP \
		, " -V, --version", USAGE_OPTSTR_VERSION

#define USAGE_MAN_TAIL(_man)   _("\nFor more details see %s.\n"), _man

#define UTIL_LINUX_VERSION _("%s from %s\n"), program_invocation_short_name, PACKAGE_STRING

#define print_version(eval) __extension__ ({ \
		printf(UTIL_LINUX_VERSION); \
		exit(eval); \
})

/*
 * scanf modifiers for "strings allocation"
 */
#ifdef HAVE_SCANF_MS_MODIFIER
#define UL_SCNsA	"%ms"
#elif defined(HAVE_SCANF_AS_MODIFIER)
#define UL_SCNsA	"%as"
#endif

/*
 * seek stuff
 */
#ifndef SEEK_DATA
# define SEEK_DATA	3
#endif
#ifndef SEEK_HOLE
# define SEEK_HOLE	4
#endif


/*
 * Macros to convert #define'itions to strings, for example
 * #define XYXXY 42
 * printf ("%s=%s\n", stringify(XYXXY), stringify_value(XYXXY));
 */
#define stringify_value(s) stringify(s)
#define stringify(s) #s

/*
 * UL_ASAN_BLACKLIST is a macro to tell AddressSanitizer (a compile-time
 * instrumentation shipped with Clang and GCC) to not instrument the
 * annotated function.  Furthermore, it will prevent the compiler from
 * inlining the function because inlining currently breaks the blacklisting
 * mechanism of AddressSanitizer.
 */
#if __has_feature(address_sanitizer) && __has_attribute(no_sanitize_memory) && __has_attribute(no_sanitize_address)
# define UL_ASAN_BLACKLIST __attribute__((noinline)) __attribute__((no_sanitize_memory)) __attribute__((no_sanitize_address))
#else
# define UL_ASAN_BLACKLIST	/* nothing */
#endif

/*
 * Note that sysconf(_SC_GETPW_R_SIZE_MAX) returns *initial* suggested size for
 * pwd buffer and in some cases it is not large enough. See POSIX and
 * getpwnam_r man page for more details.
 */
#define UL_GETPW_BUFSIZ	(16 * 1024)

/*
 * Darwin or other BSDs may only have MAP_ANON. To get it on Darwin we must
 * define _DARWIN_C_SOURCE before including sys/mman.h. We do this in config.h.
 */
#if !defined MAP_ANONYMOUS && defined MAP_ANON
# define MAP_ANONYMOUS  (MAP_ANON)
#endif

#endif /* UTIL_LINUX_C_H */
Commit	Line	Data
4d0dbb8b KZ	1	/*
	2	* Fundamental C definitions.
	3	*/
	4
	5	#ifndef UTIL_LINUX_C_H
	6	#define UTIL_LINUX_C_H
	7
	8	#include <limits.h>
aa1f95c3	9	#include <stddef.h>
eb76ca98 FG	10	#include <stdint.h>
eb76ca98 FG	11	#include <stdio.h>
9199f5cd	12	#include <unistd.h>
eb76ca98	13	#include <stdarg.h>
4d498513	14	#include <stdlib.h>
eb76ca98 FG	15	#include <string.h>
	16	#include <errno.h>
	17
2c656779 KZ	18	#include <assert.h>
2c656779 KZ	19
eb76ca98 FG	20	#ifdef HAVE_ERR_H
	21	# include <err.h>
	22	#endif
4d0dbb8b	23
075d2c07 KZ	24	#ifdef HAVE_SYS_SYSMACROS_H
	25	# include <sys/sysmacros.h> /* for major, minor */
	26	#endif
	27
790119b8 KZ	28	#ifndef LOGIN_NAME_MAX
	29	# define LOGIN_NAME_MAX 256
	30	#endif
	31
7d5976f8 SJ	32	#ifndef NAME_MAX
	33	# define NAME_MAX PATH_MAX
	34	#endif
	35
4d0dbb8b	36	/*
34b0a305 KZ	37	* __GNUC_PREREQ is deprecated in favour of __has_attribute() and
34b0a305 KZ	38	* __has_feature(). The __has macros are supported by clang and gcc>=5.
4d0dbb8b	39	*/
40084d0d KZ	40	#ifndef __GNUC_PREREQ
	41	# if defined __GNUC__ && defined __GNUC_MINOR__
	42	# define __GNUC_PREREQ(maj, min) \
	43	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
	44	# else
	45	# define __GNUC_PREREQ(maj, min) 0
	46	# endif
	47	#endif
	48
4d0dbb8b KZ	49	#ifdef __GNUC__
	50
	51	/* &a[0] degrades to a pointer: a different type from an array */
	52	# define __must_be_array(a) \
bfda68fd	53	UL_BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(__typeof__(a), __typeof__(&a[0])))
4d0dbb8b	54
2a0d2a8e	55	# define ignore_result(x) __extension__ ({ \
c764e1a4	56	__typeof__(x) __dummy __attribute__((__unused__)) = (x); (void) __dummy; \
c25dc28d	57	})
2dd570ec	58
4d0dbb8b KZ	59	#else /* !__GNUC__ */
	60	# define __must_be_array(a) 0
	61	# define __attribute__(_arg_)
2dd570ec	62	# define ignore_result(x) ((void) (x))
4d0dbb8b KZ	63	#endif /* !__GNUC__ */
4d0dbb8b KZ	64
34b0a305 KZ	65	/*
	66	* It evaluates to 1 if the attribute/feature is supported by the current
	67	* compilation targed. Fallback for old compilers.
	68	*/
	69	#ifndef __has_attribute
	70	#define __has_attribute(x) 0
	71	#endif
	72
	73	#ifndef __has_feature
	74	#define __has_feature(x) 0
	75	#endif
	76
40084d0d KZ	77	/*
	78	* Function attributes
	79	*/
	80	#ifndef __ul_alloc_size
34b0a305	81	# if (__has_attribute(alloc_size) && __has_attribute(warn_unused_result)) \|\| __GNUC_PREREQ (4, 3)
c9678832	82	# define __ul_alloc_size(s) __attribute__((alloc_size(s), warn_unused_result))
40084d0d KZ	83	# else
	84	# define __ul_alloc_size(s)
	85	# endif
	86	#endif
	87
	88	#ifndef __ul_calloc_size
34b0a305	89	# if (__has_attribute(alloc_size) && __has_attribute(warn_unused_result)) \|\| __GNUC_PREREQ (4, 3)
c9678832	90	# define __ul_calloc_size(n, s) __attribute__((alloc_size(n, s), warn_unused_result))
40084d0d KZ	91	# else
	92	# define __ul_calloc_size(n, s)
	93	# endif
	94	#endif
4d0dbb8b	95
34b0a305	96	#if __has_attribute(returns_nonnull) \|\| __GNUC_PREREQ (4, 9)
f1b327f8 SK	97	# define __ul_returns_nonnull __attribute__((returns_nonnull))
	98	#else
	99	# define __ul_returns_nonnull
	100	#endif
	101
68411ba2 BS	102	/*
68411ba2 BS	103	* Force a compilation error if condition is true, but also produce a
4d0dbb8b	104	* result (of value 0 and type size_t), so the expression can be used
68411ba2	105	* e.g. in a structure initializer (or wherever else comma expressions
4d0dbb8b KZ	106	* aren't permitted).
4d0dbb8b KZ	107	*/
2a0d2a8e	108	#define UL_BUILD_BUG_ON_ZERO(e) __extension__ (sizeof(struct { int:-!!(e); }))
4d0dbb8b KZ	109	#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
	110
	111	#ifndef ARRAY_SIZE
	112	# define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
	113	#endif
	114
	115	#ifndef PATH_MAX
	116	# define PATH_MAX 4096
	117	#endif
	118
	119	#ifndef TRUE
	120	# define TRUE 1
	121	#endif
	122
	123	#ifndef FALSE
	124	# define FALSE 0
	125	#endif
	126
70502c52	127	#ifndef min
2a0d2a8e	128	# define min(x, y) __extension__ ({ \
c764e1a4 SK	129	__typeof__(x) _min1 = (x); \
c764e1a4 SK	130	__typeof__(y) _min2 = (y); \
1cb1641d KZ	131	(void) (&_min1 == &_min2); \
1cb1641d KZ	132	_min1 < _min2 ? _min1 : _min2; })
70502c52	133	#endif
1cb1641d	134
70502c52	135	#ifndef max
2a0d2a8e	136	# define max(x, y) __extension__ ({ \
c764e1a4 SK	137	__typeof__(x) _max1 = (x); \
c764e1a4 SK	138	__typeof__(y) _max2 = (y); \
1cb1641d KZ	139	(void) (&_max1 == &_max2); \
1cb1641d KZ	140	_max1 > _max2 ? _max1 : _max2; })
70502c52	141	#endif
1cb1641d	142
19ff8ff7 KZ	143	#ifndef cmp_numbers
	144	# define cmp_numbers(x, y) __extension__ ({ \
	145	__typeof__(x) _a = (x); \
	146	__typeof__(y) _b = (y); \
	147	(void) (&_a == &_b); \
764b697c	148	_a == _b ? 0 : _a > _b ? 1 : -1; })
19ff8ff7 KZ	149	#endif
19ff8ff7 KZ	150
5b9df028 DB	151	#ifndef offsetof
	152	#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
	153	#endif
	154
eb06d5d4 KZ	155	/*
	156	* container_of - cast a member of a structure out to the containing structure
	157	* @ptr: the pointer to the member.
	158	* @type: the type of the container struct this is embedded in.
	159	* @member: the name of the member within the struct.
	160	*/
ae278c88	161	#ifndef container_of
eb06d5d4	162	#define container_of(ptr, type, member) __extension__ ({ \
1866fa6a RM	163	const __typeof__( ((type )0)->member ) __mptr = (ptr); \
1866fa6a RM	164	(type )( (char )__mptr - offsetof(type,member) );})
ae278c88	165	#endif
5b9df028	166
4b2b6716	167	#ifndef HAVE_PROGRAM_INVOCATION_SHORT_NAME
	168	# ifdef HAVE___PROGNAME
	169	extern char *__progname;
	170	# define program_invocation_short_name __progname
	171	# else
	172	# ifdef HAVE_GETEXECNAME
4b2b6716	173	# define program_invocation_short_name \
	174	prog_inv_sh_nm_from_file(getexecname(), 0)
	175	# else
	176	# define program_invocation_short_name \
	177	prog_inv_sh_nm_from_file(__FILE__, 1)
	178	# endif
	179	static char prog_inv_sh_nm_buf[256];
	180	static inline char *
	181	prog_inv_sh_nm_from_file(char *f, char stripext)
	182	{
	183	char *t;
	184
	185	if ((t = strrchr(f, '/')) != NULL)
	186	t++;
	187	else
	188	t = f;
	189
	190	strncpy(prog_inv_sh_nm_buf, t, sizeof(prog_inv_sh_nm_buf) - 1);
	191	prog_inv_sh_nm_buf[sizeof(prog_inv_sh_nm_buf) - 1] = '\0';
	192
	193	if (stripext && (t = strrchr(prog_inv_sh_nm_buf, '.')) != NULL)
	194	*t = '\0';
	195
	196	return prog_inv_sh_nm_buf;
	197	}
	198	# endif
	199	#endif
	200
06ceeef8	201
eb76ca98 FG	202	#ifndef HAVE_ERR_H
	203	static inline void
	204	errmsg(char doexit, int excode, char adderr, const char *fmt, ...)
	205	{
	206	fprintf(stderr, "%s: ", program_invocation_short_name);
	207	if (fmt != NULL) {
	208	va_list argp;
	209	va_start(argp, fmt);
	210	vfprintf(stderr, fmt, argp);
	211	va_end(argp);
	212	if (adderr)
	213	fprintf(stderr, ": ");
	214	}
	215	if (adderr)
960cf573	216	fprintf(stderr, "%m");
eb76ca98 FG	217	fprintf(stderr, "\n");
	218	if (doexit)
	219	exit(excode);
	220	}
	221
	222	#ifndef HAVE_ERR
	223	# define err(E, FMT...) errmsg(1, E, 1, FMT)
	224	#endif
	225
	226	#ifndef HAVE_ERRX
	227	# define errx(E, FMT...) errmsg(1, E, 0, FMT)
	228	#endif
	229
	230	#ifndef HAVE_WARN
	231	# define warn(FMT...) errmsg(0, 0, 1, FMT)
	232	#endif
	233
	234	#ifndef HAVE_WARNX
	235	# define warnx(FMT...) errmsg(0, 0, 0, FMT)
	236	#endif
	237	#endif /* !HAVE_ERR_H */
	238
	239
3077b371 KZ	240	/* Don't use inline function to avoid '#include "nls.h"' in c.h
	241	*/
	242	#define errtryhelp(eval) __extension__ ({ \
	243	fprintf(stderr, _("Try '%s --help' for more information.\n"), \
	244	program_invocation_short_name); \
	245	exit(eval); \
	246	})
	247
cf654e1c KZ	248	/* After failed execvp() */
	249	#define EX_EXEC_FAILED 126 /* Program located, but not usable. */
	250	#define EX_EXEC_ENOENT 127 /* Could not find program to exec. */
	251	#define errexec(name) err(errno == ENOENT ? EX_EXEC_ENOENT : EX_EXEC_FAILED, \
	252	_("failed to execute %s"), name)
	253
3077b371	254
973af806 KZ	255	static inline __attribute__((const)) int is_power_of_2(unsigned long num)
	256	{
	257	return (num != 0 && ((num & (num - 1)) == 0));
	258	}
	259
5be1c033 FG	260	#ifndef HAVE_LOFF_T
	261	typedef int64_t loff_t;
	262	#endif
	263
d58c47d9 FG	264	#if !defined(HAVE_DIRFD) && (!defined(HAVE_DECL_DIRFD) \|\| HAVE_DECL_DIRFD == 0) && defined(HAVE_DIR_DD_FD)
	265	#include <sys/types.h>
	266	#include <dirent.h>
	267	static inline int dirfd(DIR *d)
	268	{
	269	return d->dd_fd;
	270	}
	271	#endif
	272
7cf78990 DB	273	/*
	274	* Fallback defines for old versions of glibc
	275	*/
e9d00e66	276	#include <fcntl.h>
2ffad204 KZ	277
	278	#ifdef O_CLOEXEC
	279	#define UL_CLOEXECSTR "e"
	280	#else
	281	#define UL_CLOEXECSTR ""
	282	#endif
	283
4799c95f KZ	284	#ifndef O_CLOEXEC
	285	#define O_CLOEXEC 0
	286	#endif
973af806	287
f51275ee GJ	288	#ifdef __FreeBSD_kernel__
	289	#ifndef F_DUPFD_CLOEXEC
	290	#define F_DUPFD_CLOEXEC 17 /* Like F_DUPFD, but FD_CLOEXEC is set */
	291	#endif
	292	#endif
	293
2ffad204	294
7cf78990 DB	295	#ifndef AI_ADDRCONFIG
	296	#define AI_ADDRCONFIG 0x0020
	297	#endif
	298
	299	#ifndef IUTF8
	300	#define IUTF8 0040000
	301	#endif
	302
1ee4dff7 SK	303	/*
	304	* MAXHOSTNAMELEN replacement
	305	*/
	306	static inline size_t get_hostname_max(void)
	307	{
	308	long len = sysconf(_SC_HOST_NAME_MAX);
	309
	310	if (0 < len)
	311	return len;
	312
	313	#ifdef MAXHOSTNAMELEN
	314	return MAXHOSTNAMELEN;
	315	#elif HOST_NAME_MAX
	316	return HOST_NAME_MAX;
	317	#endif
	318	return 64;
	319	}
	320
2a31396a	321	/*
68411ba2 BS	322	* The usleep function was marked obsolete in POSIX.1-2001 and was removed
	323	* in POSIX.1-2008. It was replaced with nanosleep() that provides more
	324	* advantages (like no interaction with signals and other timer functions).
2a31396a	325	*/
a5bd7939 KZ	326	#include <time.h>
	327
	328	static inline int xusleep(useconds_t usec)
2a31396a	329	{
a5bd7939	330	#ifdef HAVE_NANOSLEEP
2a31396a KZ	331	struct timespec waittime = {
	332	.tv_sec = usec / 1000000L,
	333	.tv_nsec = (usec % 1000000L) * 1000
b33f24b2 WF	334	};
b33f24b2 WF	335	return nanosleep(&waittime, NULL);
a5bd7939 KZ	336	#elif defined(HAVE_USLEEP)
	337	return usleep(usec);
	338	#else
	339	# error "System with usleep() or nanosleep() required!"
2a31396a	340	#endif
a5bd7939	341	}
2a31396a	342
cd7accd4 SK	343	/*
cd7accd4 SK	344	* Constant strings for usage() functions. For more info see
6e2d5a44	345	* Documentation/{howto-usage-function.txt,boilerplate.c}
cd7accd4 SK	346	*/
	347	#define USAGE_HEADER _("\nUsage:\n")
	348	#define USAGE_OPTIONS _("\nOptions:\n")
513bfbef	349	#define USAGE_FUNCTIONS _("\nFunctions:\n")
6e2d5a44	350	#define USAGE_COMMANDS _("\nCommands:\n")
c3a4cfc5	351	#define USAGE_COLUMNS _("\nAvailable output columns:\n")
82b219f7	352	#define USAGE_SEPARATOR "\n"
b1a294c4	353
551b9cd3	354	#define USAGE_OPTSTR_HELP _("display this help")
08e3c9e6	355	#define USAGE_OPTSTR_VERSION _("display version")
b1a294c4	356
f45f3ec3	357	#define USAGE_HELP_OPTIONS(marg_dsc) \
b1a294c4 RM	358	"%-" #marg_dsc "s%s\n" \
	359	"%-" #marg_dsc "s%s\n" \
	360	, " -h, --help", USAGE_OPTSTR_HELP \
f45f3ec3	361	, " -V, --version", USAGE_OPTSTR_VERSION
b1a294c4	362
6f162034	363	#define USAGE_MAN_TAIL(_man) _("\nFor more details see %s.\n"), _man
cd7accd4 SK	364
	365	#define UTIL_LINUX_VERSION _("%s from %s\n"), program_invocation_short_name, PACKAGE_STRING
	366
2c308875 KZ	367	#define print_version(eval) __extension__ ({ \
	368	printf(UTIL_LINUX_VERSION); \
	369	exit(eval); \
	370	})
	371
640fc1b8 KZ	372	/*
	373	* scanf modifiers for "strings allocation"
	374	*/
	375	#ifdef HAVE_SCANF_MS_MODIFIER
	376	#define UL_SCNsA "%ms"
	377	#elif defined(HAVE_SCANF_AS_MODIFIER)
	378	#define UL_SCNsA "%as"
	379	#endif
	380
9199f5cd KZ	381	/*
	382	* seek stuff
	383	*/
	384	#ifndef SEEK_DATA
	385	# define SEEK_DATA 3
	386	#endif
	387	#ifndef SEEK_HOLE
	388	# define SEEK_HOLE 4
	389	#endif
	390
ff1aaf99 SK	391
	392	/*
	393	* Macros to convert #define'itions to strings, for example
	394	* #define XYXXY 42
	395	* printf ("%s=%s\n", stringify(XYXXY), stringify_value(XYXXY));
	396	*/
	397	#define stringify_value(s) stringify(s)
	398	#define stringify(s) #s
	399
d763c230 SK	400	/*
	401	* UL_ASAN_BLACKLIST is a macro to tell AddressSanitizer (a compile-time
	402	* instrumentation shipped with Clang and GCC) to not instrument the
	403	* annotated function. Furthermore, it will prevent the compiler from
	404	* inlining the function because inlining currently breaks the blacklisting
	405	* mechanism of AddressSanitizer.
	406	*/
34b0a305 KZ	407	#if __has_feature(address_sanitizer) && __has_attribute(no_sanitize_memory) && __has_attribute(no_sanitize_address)
34b0a305 KZ	408	# define UL_ASAN_BLACKLIST __attribute__((noinline)) __attribute__((no_sanitize_memory)) __attribute__((no_sanitize_address))
d763c230 SK	409	#else
	410	# define UL_ASAN_BLACKLIST /* nothing */
	411	#endif
	412
f7ac9e71 KZ	413	/*
	414	* Note that sysconf(_SC_GETPW_R_SIZE_MAX) returns initial suggested size for
	415	* pwd buffer and in some cases it is not large enough. See POSIX and
	416	* getpwnam_r man page for more details.
	417	*/
	418	#define UL_GETPW_BUFSIZ (16 * 1024)
	419
40733239 RM	420	/*
	421	* Darwin or other BSDs may only have MAP_ANON. To get it on Darwin we must
	422	* define _DARWIN_C_SOURCE before including sys/mman.h. We do this in config.h.
	423	*/
	424	#if !defined MAP_ANONYMOUS && defined MAP_ANON
	425	# define MAP_ANONYMOUS (MAP_ANON)
	426	#endif
	427
4d0dbb8b	428	#endif /* UTIL_LINUX_C_H */