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| Conversions to and from numeric formats | |||||||||||||||||||||||||||||||||||||||||
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| String manipulation | |||||||||||||||||||||||||||||||||||||||||
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| String examination | |||||||||||||||||||||||||||||||||||||||||
| Memory manipulation | |||||||||||||||||||||||||||||||||||||||||
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(C11)(C11) | |||||||||||||||||||||||||||||||||||||||||
Defined in header <inttypes.h> | ||
intmax_t strtoimax(constchar*restrict nptr, char**restrict endptr,int base); | (1) | (since C99) |
uintmax_t strtoumax(constchar*restrict nptr, char**restrict endptr,int base); | (2) | (since C99) |
Interprets an integer value in a byte string pointed to bynptr.
Discards any whitespace characters (as identified by callingisspace) until the first non-whitespace character is found, then takes as many characters as possible to form a validbase-n (where n=base) integer number representation and converts them to an integer value. The valid integer value consists of the following parts:
0) indicating octal base (applies only when the base is8 or0)0x or0X) indicating hexadecimal base (applies only when the base is16 or0)The set of valid values for base is{0, 2, 3, ..., 36}. The set of valid digits for base-2 integers is{0, 1}, for base-3 integers is{0, 1, 2}, and so on. For bases larger than10, valid digits include alphabetic characters, starting fromAa for base-11 integer, toZz for base-36 integer. The case of the characters is ignored.
Additional numeric formats may be accepted by the currently installed Clocale.
If the value ofbase is0, the numeric base is auto-detected: if the prefix is0, the base is octal, if the prefix is0x or0X, the base is hexadecimal, otherwise the base is decimal.
If the minus sign was part of the input sequence, the numeric value calculated from the sequence of digits is negated as if byunary minus in the result type.
The functions sets the pointer pointed to byendptr to point to the character past the last character interpreted. Ifendptr is a null pointer, it is ignored.
If thenptr is empty or does not have the expected form, no conversion is performed, and (ifendptr is not a null pointer) the value ofnptr is stored in the object pointed to byendptr.
Contents |
| nptr | - | pointer to the null-terminated byte string to be interpreted |
| endptr | - | pointer to a pointer to character |
| base | - | base of the interpreted integer value |
str is returned.#include <errno.h>#include <inttypes.h>#include <stdio.h>#include <string.h> int main(void){char* endptr=NULL; printf("%ld\n", strtoimax(" -123junk",&endptr,10));// base 10printf("%ld\n", strtoimax("11111111",&endptr,2));// base 2printf("%ld\n", strtoimax("XyZ",&endptr,36));// base 36printf("%ld\n", strtoimax("010",&endptr,0));// octal auto-detectionprintf("%ld\n", strtoimax("10",&endptr,0));// decimal auto-detectionprintf("%ld\n", strtoimax("0x10",&endptr,0));// hexadecimal auto-detection // range error: LONG_MAX+1 --> LONG_MAXerrno=0;printf("%ld\n", strtoimax("9223372036854775808",&endptr,10));printf("%s\n",strerror(errno));}
Output:
-12325544027810169223372036854775807Numerical result out of range
(C99)(C99) | converts a wide string tointmax_t oruintmax_t (function)[edit] |
(C99) | converts a byte string to an integer value (function)[edit] |
(C99) | converts a byte string to an unsigned integer value (function)[edit] |
C++ documentation forstrtoimax,strtoumax | |
