strtoimax, _strtoimax_l, wcstoimax, _wcstoimax_l

Converts a string to an integer value of the largest supported signed integer type.

Syntax

intmax_t strtoimax(
   const char *strSource,
   char **endptr,
   int base
);
intmax_t wcstoimax(
   const wchar_t *strSource,
   wchar_t **endptr,
   int base
);
intmax_t _strtoimax_l(
   const char *strSource,
   char **endptr,
   int base,
   _locale_t locale
);
intmax_t _wcstoimax_l(
   const wchar_t *strSource,
   wchar_t **endptr,
   int base,
   _locale_t locale
);

Parameters

strSource
Null-terminated string to convert.

endptr
Pointer to the character that stops the scan.

base
Number base to use.

locale
The locale to use.

Return value

strtoimax returns the value that's represented in the string strSource, except when the representation would cause an overflow—in that case, it returns INTMAX_MAX or INTMAX_MIN, and errno is set to ERANGE. The function returns 0 if no conversion can be performed. wcstoimax returns values analogously to strtoimax.

INTMAX_MAX and INTMAX_MIN are defined in stdint.h.

If strSource is NULL or the base is nonzero and either less than 2 or greater than 36, errno is set to EINVAL.

For more information about return codes, see errno, _doserrno, _sys_errlist, and _sys_nerr.

Remarks

The strtoimax function converts strSource to an intmax_t. The wide-character version of strtoimax is wcstoimax; its strSource argument is a wide-character string. Otherwise, these functions behave identically. Both functions stop reading the string strSource at the first character they can't recognize as part of a number. It may be the terminating null character, or it may be the first numeric character that's greater than or equal to base.

The locale's LC_NUMERIC category setting determines recognition of the radix character in strSource; for more information, see setlocale, _wsetlocale. The functions that don't have the _l suffix use the current locale; _strtoimax_l and _wcstoimax_l are identical to the corresponding functions that don't have the _l suffix except that they instead use the locale that's passed in. For more information, see Locale.

If endptr isn't NULL, a pointer to the character that stopped the scan is stored at the location that's pointed to by endptr. If no conversion can be performed (no valid digits were found or an invalid base was specified), the value of strSource is stored at the location that's pointed to by endptr.

Generic-text routine mappings

strtoimax expects strSource to point to a string of the following form:

[whitespace] [{+ | -}] [0 [{ x | X }]] [digits | letters]

A whitespace may consist of space and tab characters, which are ignored; digits are one or more decimal digits; letters are one or more of the letters 'a' through 'z' (or 'A' through 'Z'). The first character that doesn't fit this form stops the scan. If base is between 2 and 36, then it's used as the base of the number. If base is 0, the initial characters of the string pointed to by strSource are used to determine the base. If the first character is '0' and the second character isn't 'x' or 'X', the string is interpreted as an octal integer. If the first character is '0' and the second character is 'x' or 'X', the string is interpreted as a hexadecimal integer. If the first character is '1' through '9', the string is interpreted as a decimal integer. The letters 'a' through 'z' (or 'A' through 'Z') are assigned the values 10 through 35; only letters whose assigned values are less than base are permitted. The first character outside the range of the base stops the scan. For example, if base is 0 and the first character scanned is '0', an octal integer is assumed and an '8' or '9' character would stop the scan.

Requirements

For more compatibility information, see Compatibility.

See also

Data conversion
Locale
localeconv
setlocale, _wsetlocale
String to numeric value functions
strtod, _strtod_l, wcstod, _wcstod_l
strtol, wcstol, _strtol_l, _wcstol_l
strtoul, _strtoul_l, wcstoul, _wcstoul_l
strtoumax, _strtoumax_l, wcstoumax, _wcstoumax_l
atof, _atof_l, _wtof, _wtof_l