The values associated with the constants specified in <float.h> are as follows:
Macro Name | Meaning | Value |
---|---|---|
FLT_RADIX | Radix of the exponent representation. | 2 |
FLT_MANT_DIG | Number of base-FLT_RADIX digits in the float significand. | 24 |
DBL_MANT_DIG | Number of base-FLT_RADIX digits in the double significand. | 53 |
LDBL_MANT_DIG | Number of base-FLT_RADIX digits in the long double significand. | 64 |
FLT_DIG | Number of decimal digits, q, such that any floating-point number with q digits can be rounded into a float representation and back again without change to the q digits. | 6 |
DBL_DIG | Number of decimal digits, q, such that any floating-point number with q digits can be rounded into a double representation and back again without change to the q digits. | 15 |
LDBL_DIG | Number of decimal digits, q, such that any floating-point number with q digits can be rounded into a long double representation and back again without change to the q digits. | 18 |
FLT_MIN_EXP | Minimum negative integer such that FLT_RADIX raised to that power minus 1 is a normalised float. | -125 |
DBL_MIN_EXP | Minimum negative integer such that FLT_RADIX raised to that power minus 1 is a normalised double. | -1021 |
LDBL_MIN_EXP | Minimum negative integer such that FLT_RADIX raised to that power minus 1 is a normalised long double. | -16381 |
FLT_MIN_10_EXP | Minimum negative integer such that 10 raised to that power is in the range of normalised floats. | -37 |
DBL_MIN_10_EXP | Minimum negative integer such that 10 raised to that power is in the range of normalised doubles. | -307 |
LDBL_MIN_10_EXP | Minimum negative integer such that 10 raised to that power is in the range of normalised long doubles. | -4931 |
FLT_MAX_EXP | Maximum integer such that FLT_RADIX raised to that power minus 1 is a representable finite float. | 128 |
DBL_MAX_EXP | Maximum integer such that FLT_RADIX raised to that power minus 1 is a representable finite double. | 1024 |
LDBL_MAX_EXP | Maximum integer such that FLT_RADIX raised to that power minus 1 is a representable finite long double. | 16384 |
FLT_MAX_10_EXP | Maximum integer such that 10 raised to that power is in the range of representable finite floats. | 38 |
DBL_MAX_10_EXP | Maximum integer such that 10 raised to that power is in the range of representable finite doubles. | 308 |
LDBL_MAX_10_EXP | Maximum integer such that 10 raised to that power is in the range of representable finite long doubles. | 4932 |
FLT_MAX | Maximum representable finite float. | 3.40282347e+38 |
DBL_MAX | Maximum representable finite double. | 1.7976931348623157e308 |
LDBL_MAX | Maximum representable finite long double. | 1.189731495357231765e+4932 |
FLT_EPSILON | Difference between 1.0 and the least value greater than 1.0 that is representable as a float. | 1.1920929e-07 |
DBL_EPSILON | Difference between 1.0 and the least value greater than 1.0 that is representable as a double. | 2.2204460492503131e-16 |
LDBL_EPSILON | Difference between 1.0 and the least value greater than 1.0 that is representable as a long double. | 1.084202172485504434e-19 |
FLT_MIN | Minimum normalised positive float. | 1.17549435e-38 |
DBL_MIN | Minimum normalised positive double. | 2.2250738585072014e-308 |
LDBL_MIN | Minimum normalised positive long double. | 3.362103143112093506e-4932 |
The values associated with the following constants (optionally specified in <limits.h> are as follows:
Macro Name | Meaning | Minimum | Maximum |
---|---|---|---|
DELAYTIMER_MAX | Maximum number of timer expiration overruns. | 1048576 | 1048576 |
FILESIZEBITS | Minimum number of bits needed to represent as a signed integer value the maximum size of a regular file. | 32 | 64 |
LINK_MAX | Maximum number of links to a single file. | 1 | 2147483647 |
MQ_OPEN_MAX | The maximum number of open message queue descriptors a process may hold. | 8 | 1024 |
MQ_PRIO_MAX | The maximum number of message priorities supported by the implementation. | 32 | 32 |
NAME_MAX | Maximum number of bytes in a filename (not including the terminating null). | 91 | 255 |
OPEN_MAX | Maximum number of open files that one process can have open at any one time. | 100 | 65534 |
PAGESIZE | Size of a page in bytes. | 4096 | 4096 |
PATH_MAX | Maximum number of bytes in a pathname (including the terminating null). | 255 | 1024 |
PTHREAD_DESTRUCTOR_ITERATIONS | Maximum number of attempts made to destroy a thread's thread-specific data values when a thread exits. | 4 | 4 |
PTHREAD_KEYS_MAX | Maximum number of data keys that can be created by a process. | 128 | 128 |
PTHREAD_STACK_MIN | Minimum size in bytes of thread stack storage. | 256 | 256 |
PTHREAD_THREADS_MAX | Maximum number of threads that can be created per process. | 65534 | 65534 |
RTSIG_MAX | Maximum number of realtime signals reserved for application use in this implementation. | 16 | 16 |
SEM_NSEMS_MAX | Maximum number of semaphores that a process may have. | Unlimited | Unlimited |
SEM_VALUE_MAX | The maximum value a semaphore may have. | 1073741823 | 1073741823 |
SIGQUEUE_MAX | Maximum number of queued signals that a process may send and have pending at the receiver(s) at any time. | Unlimited | Unlimited |
SS_REPL_MAX | The maximum number of replenishment operations that may be simultaneously pending for a particular sporadic server scheduler. | 65535 | 65535 |
STREAM_MAX | Number of streams that one process can have open at one time. | Unlimited | Unlimited |
TIMER_MAX | Maximum number of timers per process supported by the implementation. | 65534 | 65534 |
TRACE_EVENT_NAME_MAX | Maximum length of the trace event name. | Not supported | Not supported |
TRACE_NAME_MAX | Maximum length of the trace generation version string or of the trace stream name. | Not supported | Not supported |
TRACE_SYS_MAX | Maximum number of trace streams that may simultaneously exist in the system. | Not supported | Not supported |
TRACE_USER_EVENT_MAX | Maximum number of user trace event type identifiers that may simultaneously exist in a traced process, including the predefined user trace event POSIX_TRACE_UNNAMED_USER_EVENT. | Not supported | Not supported |
TZNAME_MAX | Maximum number of bytes supported for the name of a time zone. | 30 | 30 |
The values associated with the following numerical constants specified in the <limits.h> header file are as follows:
Macro Name | Meaning | Value |
---|---|---|
CHAR_MAX | Maximum value of a char. | 127 |
INT_MAX | Maximum value of an int. | 2147483647 |
LONG_MAX | Maximum value of a long int. | 2147483647 |
LLONG_MAX | Maximum value of a long long. | 9223372036854775807 |
SHRT_MAX | Maximum value of a short. | 32767 |
SSIZE_MAX | Maximum value of an object of type ssize_t. | 2147483647 |
UINT_MAX | Maximum value of an unsigned int. | 4294967295 |
ULONG_MAX | Maximum value of an unsigned long int. | 4294967295 |
ULLONG_MAX | Maximum value of a unsigned long long. | 18446744073709551615 |
USHRT_MAX | Maximum value of an unsigned short int. | 65535 |
The values associated with the numerical constants specified in the <stdio.h> header file are as follows:
Macro Name | Meaning | Value |
---|---|---|
FILENAME_MAX | Maximum size in bytes of the longest filename string that the implementation guarantees can be opened. | 255 |
FOPEN_MAX | Number of streams which the implementation guarantees can be open simultaneously. | 16 |
L_tmpnam | Maximum size of character array to hold tmpnam() output. | 255 |
TMP_MAX | Minimum number of unique filenames generated by tmpnam(), which is the maximum number of times an application can call tmpnam() reliably. | 17576 |