---
name: "String::Scanf"
section: "3pm"
platform: "linux"
package: "libstring-scanf-perl"
version: "2.1-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/String::Scanf"
---

# String::Scanf(3pm)

emulate sscanf() of the C library

## NAME

String::Scanf - emulate sscanf() of the C library

## SYNOPSIS

```
    use String::Scanf; # imports sscanf()
    ($a, $b, $c, $d) = sscanf("%d+%d %f-%s", $input);
    ($e, $f, $g, $h) = sscanf("%x %o %s:%3c"); # input defaults to $_
    $r = String::Scanf::format_to_re($f);
```

or

```
    # works only for Perl 5.005 or later
    use String::Scanf qw(); # import nothing
    my $s1 = String::Scanf->new("%d+%d %f-%s");
    my $s2 = String::Scanf->new("%x %o %s:%3c");
    ($a, $b, $c, $d) = $s1->sscanf($input);
    ($e, $f, $g, $h) = $s2->sscanf(); # input defaults to $_
```

## DESCRIPTION

String::Scanf supports scanning strings for data using formats similar to the libc/stdio **sscanf()**.

The supported **sscanf()** formats are as follows:

- %d

  Decimal integer, with optional plus or minus sign.

- %u

  Decimal unsigned integer, with optional plus sign.

- %x

  Hexadecimal unsigned integer, with optional "0x" or "0x" in front.

- %o

  Octal unsigned integer.

- %e %f %g

  (The \[efg\] work identically.)

  Decimal floating point number, with optional plus or minus sign, in any of these formats:

  ```
      1
      1.
      1.23
      .23
      1e45
      1.e45
      1.23e45
      .23e45
  ```

  The exponent has an optional plus or minus sign, and the `"e"` may also be `"E"`.

  The various borderline cases like `"Inf"` and `"Nan"` are not recognized.

- %s

  A non-whitespace string.

- %c

  A string of characters.  An array reference is returned containing the numerical values of the characters.

- %%

  A literal `"%"`.

The **sscanf()** formats \[pnSC\] are not supported.

The `%s` and `%c` have an optional maximum width, e.g. `%4s`, in which case at most so many characters are consumed (but fewer characters are also accecpted).

The numeric formats may also have such a width but it is ignored.

The numeric formats may have `"[hl]"` before the main option, e.g. `%hd`, but since such widths have no meaning in Perl, they are ignored.

Non-format parts of the parameter string are matched literally (e.g. `":"` matches as `":"`), expect that any whitespace is matched as any whitespace (e.g. `" "` matches as `"\s+"`).

## WARNING

The numeric formats match only something that looks like a number, they do not care whether it fits into the numbers of Perl.  In other words, `123e456789` is valid for `"sscanf()"`, but quite probably it won't fit into your Perl's numbers.  Consider using the various Math::\* modules instead.

## AUTHOR, COPYRIGHT AND LICENSE

Jarkko Hietaniemi \<jhi@iki.fi\>

Copyright (c) 2002,2004 Jarkko Hietaniemi.  All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.