# strtol(3) [redhat man page]

STRTOL(3) Linux Programmer's Manual STRTOL(3)NAME

strtol, strtoll, strtoq - convert a string to a long integer.SYNOPSIS

#include <stdlib.h> long int strtol(const char *nptr, char **endptr, int base); long long int strtoll(const char *nptr, char **endptr, int base);DESCRIPTION

The strtol() function converts the initial part of 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 `' but **endptr is `' on return, the entire string is valid. The strtoll() function works just like the strtol() function but returns a long long integer value.RETURN VALUE

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. Precisely the same holds for strtoll() (with LLONG_MIN and LLONG_MAX instead of LONG_MIN and LONG_MAX).ERRORS

ERANGE The resulting value was out of range. EINVAL (not in C99) The given base contains an unsupported value. The implementation may also set errno to EINVAL in case no conversion was performed (no digits seen, and 0 returned).NOTES

In locales other than the "C" locale, also other strings may be accepted. (For example, the thousands separator of the current locale may be supported.) BSD also has quad_t strtoq(const char *nptr, char **endptr, int base); with completely analogous definition. Depending on the wordsize of the current architecture, this may be equivalent to strtoll() or to strtol().CONFORMING TO

strtol() conforms to SVID 3, BSD 4.3, ISO 9899 (C99) and POSIX, and strtoll() to ISO 9899 (C99) and POSIX-2001.SEE ALSO

atof(3), atoi(3), atol(3), strtod(3), strtoul(3)GNU

2002-05-30 STRTOL(3)

## Check Out this Related Man Page

STRTOL(3) BSD Library Functions Manual STRTOL(3)NAME

strtol, strtoll, strtoimax, strtoqconvert a string value to a long, long long, intmax_t or quad_t integer--LIBRARY

Standard C Library (libc, -lc)SYNOPSIS

#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);DESCRIPTION

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 charac- ter 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' repre- sents 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 '' but **endptr is '' on return, the entire string was valid.)RETURN VALUES

The strtol(), strtoll(), strtoimax() and strtoq() functions return the result of the conversion, unless the value would underflow or over- flow. 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_MAXERRORS

[EINVAL] The value of base is not supported or no conversion could be performed (the last feature is not portable across all plat- forms). [ERANGE] The given string was out of range; the value converted has been clamped.SEE ALSO

atof(3), atoi(3), atol(3), strtod(3), strtonum(3), strtoul(3), wcstol(3)STANDARDS

The strtol() function conforms to ISO/IEC 9899:1990 (``ISO C90''). The strtoll() and strtoimax() functions conform to ISO/IEC 9899:1999 (``ISO C99''). The BSD strtoq() function is deprecated.BSD

November 28, 2001 BSD