STRTOL(3) BSD Library Functions Manual STRTOL(3)
NAME
strtoimax, strtol, strtoll, strtoq -- convert a string value to a long, long long, intmax_t or quad_t
integer
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <inttypes.h>
intmax_t
strtoimax(const char *restrict str, char **restrict endptr, int base);
#include <stdlib.h>
long
strtol(const char *restrict str, char **restrict endptr, int base);
long long
strtoll(const char *restrict str, char **restrict endptr, int base);
#include <sys/types.h>
#include <stdlib.h>
#include <limits.h>
quad_t
strtoq(const char *str, char **endptr, int base);
DESCRIPTION
The strtol() function converts the string in str to a long value. The strtoll() function converts the
string in str to a long long value. The strtoimax() function converts the string in str to an intmax_t
value. The strtoq() function converts the string in str 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 str in *endptr. (Thus, if *str
is not `\0' but **endptr is `\0' on return, the entire string was valid.)
Extended locale versions of these functions are documented in strtol_l(3). See xlocale(3) for more
information.
RETURN VALUES
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 (the last feature is not portable across all platforms). If
an overflow or underflow occurs, errno is set to ERANGE and the function return value is clamped
according to the following table.
Function underflow overflow
strtol() LONG_MIN LONG_MAX
strtoll() LLONG_MIN LLONG_MAX
strtoimax() INTMAX_MIN INTMAX_MAX
strtoq() LLONG_MIN LLONG_MAX
ERRORS
[EINVAL] The value of base is not supported or no conversion could be performed (the last
feature is not portable across all platforms).
[ERANGE] The given string was out of range; the value converted has been clamped.
LEGACY SYNOPSIS
#include <stdlib.h>
#include <limits.h>
<limits.h> is necessary for the strtol() and strtoll() functions.
SEE ALSO
atof(3), atoi(3), atol(3), strtod(3), strtol_l(3), strtoul(3), wcstol(3), compat(5)
STANDARDS
The strtol() function conforms to ISO/IEC 9899:1990 (``ISO C90''). The strtoll() and strtoimax() func-tions functions
tions conform to ISO/IEC 9899:1999 (``ISO C99''). The BSD strtoq() function is deprecated.
BSD November 28, 2001 BSD
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