function
<cstdlib>

strtoll

long long int strtoll (const char* str, char** endptr, int base);
Convert string to long long integer
Parses the C-string str interpreting its content as an integral number of the specified base, which is returned as a value of type long long int. If endptr is not a null pointer, the function also sets the value of endptr to point to the first character after the number.

This function operates like strtol to interpret the string, but produces numbers of type long long int (see strtol for details on the interpretation process).

Parameters

str
C-string beginning with the representation of an integral number.
endptr
Reference to an object of type char*, whose value is set by the function to the next character in str after the numerical value.
This parameter can also be a null pointer, in which case it is not used.
base
Numerical base (radix) that determines the valid characters and their interpretation.
If this is 0, the base used is determined by the format in the sequence (see strtol for details).

Return Value

On success, the function returns the converted integral number as a long int value.
If no valid conversion could be performed, a zero value is returned (0LL).
If the value read is out of the range of representable values by a long long int, the function returns LLONG_MAX or LLONG_MIN (defined in <climits>), and errno is set to ERANGE.

Example

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/* strtoll example */
#include <stdio.h>      /* printf, NULL */
#include <stdlib.h>     /* strtoll */

int main ()
{
  char szNumbers[] = "1856892505 17b00a12b -01100011010110000010001101100 0x6fffff";
  char* pEnd;
  long long int lli1, lli2, lli3, lli4;
  lli1 = strtoll (szNumbers, &pEnd, 10);
  lli2 = strtoll (pEnd, &pEnd, 16);
  lli3 = strtoll (pEnd, &pEnd, 2);
  lli4 = strtoll (pEnd, NULL, 0);
  printf ("The decimal equivalents are: %lld, %lld, %lld and %lld.\n", lli1, lli2, lli3, lli4);
  return 0;
}


Possible output:

The decimal equivalents are: 1856892505, 6358606123, -208340076 and 7340031

Data races

The array pointed by str is accessed, and the pointer pointed by endptr is modified (if not null).

Exceptions (C++)

No-throw guarantee: this function never throws exceptions.

If str does not point to a valid C-string, or if endptr does not point to a valid pointer object, it causes undefined behavior.

See also

strtol
Convert string to long integer (function )
atol
Convert string to long integer (function )
strtoull
Convert string to unsigned long long integer (function )
strtod
Convert string to double (function )

C++