strtol - convert a string to a long integer.
#include <stdlib.h>
long int strtol(const char *nptr, char **endptr, int base);
The strtol() function converts the string in nptr to a long integer
value according to the given base, which must be between 2 and 36
inclusive, or be the special value 0.
The string must begin with an arbitrary amount of white space (as
determined by isspace(3)) followed by a single optional `+' or `-'
sign. If base is zero or 16, the string may then include a `0x' prefix,
and the number will be read in base 16; otherwise, a zero base is
taken as 10 (decimal) unless the next character is `0', in which case
it is taken as 8 (octal).
The remainder of the string is converted to a long int value in the
obvious manner, stopping at the first character which is not a valid
digit in the given base. (In bases above 10, the letter `A' in either
upper or lower case represents 10, `B' represents 11, and so forth,
with `Z' representing 35.)
If endptr is not NULL, strtol() stores the address of the first invalid
character in *endptr. If there were no digits at all, strtol() stores
the original value of nptr in *endptr (and returns 0). In particular,
if *nptr is not `\0' but **endptr is `\0' on return, the entire string
is valid.
The strtol() function returns the result of the conversion, unless the
value would underflow or overflow. If an underflow occurs, strtol()
returns LONG_MIN. If an overflow occurs, strtol() returns LONG_MAX.
In both cases, errno is set to ERANGE.
ERANGE The given string was out of range; the value converted has been
clamped.
SVID 3, BSD 4.3, ISO 9899
atof(3), atoi(3), atol(3), strtod(3), strtoul(3)
Ignores the current locale.
GNU 1995-06-10 STRTOL(3)
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