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LETTERatoiULETTER Converts an ASCII string into an integer.

Overview
#include <stdlib.h>

x = atoi(s);

int x;
const char *s;

Portability
ANSI

Description
"atoi" converts an ASCII string consisting of decimal numbers to its appropiate integer value. It is the same as calling:
(int) strtol(string, 0, 10)

The ASCII string must have the form:
[ws][sign]digits
where ws stands for any number of whitespaces (plain spaces and tabs), sign is either '+' or '-' and digits means a sequence of numbers between 0 and 9. All elements within "[]" brackets are optional. This function does not check for integer overflow.

Returns
This function returns the integer value if the ASCII string could be converted successfully and 0 otherwise.

See also
atof , atol , strtod , strtol

Example
#include <stdlib.h>

void main(void)
{
int x;
char *cp = " 567";

x = atoi(cp);
printf("Converted to %d\n",x);
}