strtol, strtoll, strtoimax, strtoq -- convert a string value to a long,
long long, intmax_t or quad_t integer
Standard C Library (libc, -lc)
#include <stdlib.h>
#include <limits.h>
long
strtol(const char * restrict nptr, char ** restrict endptr, int base);
long long
strtoll(const char * restrict nptr, char ** restrict endptr, int base);
#include <inttypes.h>
intmax_t
strtoimax(const char * restrict nptr, char ** restrict endptr, int base);
#include <sys/types.h>
#include <stdlib.h>
#include <limits.h>
quad_t
strtoq(const char *nptr, char **endptr, int base);
The strtol() function converts the string in nptr to a long value. The
strtoll() function converts the string in nptr to a long long value. The
strtoimax() function converts the string in nptr to an intmax_t value.
The strtoq() function converts the string in nptr to a quad_t value. The
conversion is done according to the given base, which must be between 2
and 36 inclusive, or be the special value 0.
The string may 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, long long, intmax_t
or quad_t 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, however, strtol()
stores the original value of nptr in *endptr. (Thus, if *nptr is not
`\0' but **endptr is `\0' on return, the entire string was valid.)
The strtol(), strtoll(), strtoimax() and strtoq() functions return the
result of the conversion, unless the value would underflow or overflow.
If no conversion could be performed, 0 is returned and the global variable
errno is set to EINVAL. If an overflow or underflow occurs, errno
is set to ERANGE and the function return value is clamped according to
the following table.
Function overflow underflow
strtol() LONG_MIN LONG_MAX
strtoll() LLONG_MIN LLONG_MAX
strtoimax() INTMAX_MIN INTMAX_MAX
strtoq() LLONG_MIN LLONG_MAX
[EINVAL] The value of base is not supported or no conversion
could be performed.
[ERANGE] The given string was out of range; the value converted
has been clamped.
atof(3), atoi(3), atol(3), strtod(3), strtoul(3), wcstol(3)
The strtol() function conforms to ISO/IEC 9899:1990 (``ISO C89''). The
strtoll() and strtoimax() functions conform to ISO/IEC 9899:1999
(``ISO C99''). The BSD strtoq() function is deprecated.
FreeBSD 5.2.1 November 28, 2001 FreeBSD 5.2.1 [ Back ] |