STRTON(3ast) STRTON(3ast)

# [NAME](#NAME)

**strton**, **strtonll** - convert string to integer with optional pseudo-float support

# [SYNOPSIS](#SYNOPSIS)

long strton(const char* s, char\** e, char \*basep, int m)

intmax\_t strtonll(const char* s, char\** e, char \*basep, int m)

# [DESCRIPTION](#DESCRIPTION)

The **strton** and **strtonll** functions convert the zero-terminated string *s* to a **long** integer or an **intmax\_t** integer, respectively. If *e* is not NULL, then *\*e* is set to point to the first unrecognized character in *s*, or to its terminating zero byte if the conversion was fully successful. Leading [*isspace*(3)](/man/os/ksh/isspace.3) characters in *s* are skipped over and ignored.

A number is composed of *sign*-*base*-*number*-*suffix*. All but *number* are optional. The *sign* may be + or -. The *base* may be **0x** for hexadecimal, **0** for octal, or *nn#* for base 2 ≤ *nn* ≤ 64.

For bases greater than 10, the digits above 9 are represented by the lower case letters, the upper case letters, “@”, and “\_”, respectively. For bases less than or equal to 36, upper and lower case letters can be used interchangeably.

If the string *s* has a *base* prefix. then the numeric value of the base detected is stored in *\*basep*, which may affect subsequent calls. If, on entry, *basep* is not NULL and the numeric value of *\*basep* is not zero, then the conversion is done from the base specified in *basep*, and the *base* prefix is not recognized.

A case-insensitive *suffix* may be specified in *s* if the base prefix is omitted. It multiplies the converted number and may be **b** for block (512), or one of the SI unit prefixes **k** for kilo (1000), **M** for mega (1000 × 1000), **G** for giga (1000 × 1000 × 1000), and so on for **T** (tera), **P** (peta), and **E** (exa), or one of the IEC power-of-two prefixes **Ki** for kibi (1024), **Mi** for mebi (1024 × 1024), **Gi** for gibi (1024 × 1024 × 1024), and so on for **Ti** (tebi), **Pi** (pebi), and **Ei** (exbi). The SI and IEC suffixes may optionally have a final **B** (i.e., bytes) added, which is accepted and ignored.

The *m* parameter may also be used to specify a multiplier. If neither a *base* prefix nor a multiplier *suffix* is supplied in *s*, and *\*basep* is 0, and a value greater than 1 is specified in the *m* parameter, then the converted value will be multiplied by *m*.

Additionally, the *m* parameter may be used to support pseudo-floating point numbers. If *m* is greater than 1, and the *suffix* consists of the currently set locale's radix point (by default, “.”), followed by decimal digits, then *s* is treated as if it were a floating point number which is multiplied by *m*. For example, an *s* string value of "12.34" combined with an *m* value of 1000 yields an integer result of 12340.

A negative *m* disables the recognition of any *suffix*. Otherwise, if neither case above applies, *m* is ignored.

# [RETURN VALUES](#RETURN_VALUES)

The **strton** and **strtonll** functions return the value that represents the conversion of zero or more recognized characters in the string *s* up to the first unrecognized character or the terminating zero byte. The address of the first unrecognized character, or the terminating zero byte, is stored in *\*e* if *e* is not NULL. Note that *errno* is not changed in this case.

If the specified base is less than 2 or greater than 64, then *\*e* is set to *s* (if *e* is not NULL), the global variable *errno* is set to EINVAL, and 0 is returned.

If an overflow or underflow occurs, then *errno* is set to ERANGE and the return value is the function's integer type's maximum possible or minimum possible value, respectively.

# [SEE ALSO](#SEE_ALSO)

[*atoi*(3)](/man/os/ksh/atoi.3), [*scanf*(3)](/man/os/ksh/scanf.3), [*setlocale*(3)](/man/os/ksh/setlocale.3), [*strtol*(3)](/man/os/ksh/strtol.3), [*strtoul*(3)](/man/os/ksh/strtoul.3), [*strtod*(3)](/man/os/ksh/strtod.3)

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Document: strton(3ast) from ksh 1.0.10-r37 (Chainguard OS)
Source: https://github.com/ksh93/ksh