nbdkit_parse_probability(3)

NAME
nbdkit_parse_probability - parse probabilities for nbdkit

SYNOPSIS
 #include <nbdkit-plugin.h>

 int nbdkit_parse_probability (const char *what, const char *str,
                               double *ret);

DESCRIPTION
Use the "nbdkit_parse_probability" utility function to parse probabilities. Common formats understood include: "0.1", "1e-1", "10%", "1:10" or "1/10", which all mean a probability of 1 in 10.

The "what" parameter is printed in error messages to provide context. The "str" parameter is the probability string.

RETURN VALUE
On success the function returns 0. If "ret != NULL", set *ret to the parsed value. If "ret == NULL", the parsing is done but the result is discarded.

The probability is always a finite number ≥ 0.0, but note the result may be larger than 1.0 (for example if "str == "200%"" then the function will set "*ret = 2.0"). If you want to clamp the upper bound the caller must do that.

On error, nbdkit_error(3) is called and -1 is returned. On error *ret is always unchanged.

LANGUAGE BINDINGS
In nbdkit-ocaml-plugin(3):

 NBDKit.parse_probability : string -> string -> float

In nbdkit-python-plugin(3):

 import nbdkit
 size = nbdkit.parse_probability(what, str)

In nbdkit-rust-plugin(3):

 use nbdkit::*;
 pub fn parse_probability(what: &str, s: &str) -> Result<f64>

HISTORY
"nbdkit_parse_probability" was added in nbdkit 1.36.

SEE ALSO
nbdkit(1), nbdkit_parse_bool(3), nbdkit_parse_delay(3), nbdkit_parse_int(3), nbdkit_parse_size(3), nbdkit-plugin(3), nbdkit-filter(3), nbdkit-error-filter(1), nbdkit-evil-filter(1).

AUTHORS
Richard W.M. Jones

COPYRIGHT
Copyright Red Hat

LICENSE
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

•   Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

•   Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

•   Neither the name of Red Hat nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

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