NAME

optstr_get, optstr_get_string, optstr_get_number, optstr_get_number_binary, optstr_get_number_hex, optstr_get_macaddr — Options string management

SYNOPSIS

#include <sys/optstr.h>

bool
optstr_get(const char *optstr, const char *key, char *buf, size_t bufsize);

bool
optstr_get_string(const char *optstr, const char *key, char **result);

bool
optstr_get_number(const char *optstr, const char *key, unsigned long *result);

bool
optstr_get_number_binary(const char *optstr, const char *key, unsigned long *result);

bool
optstr_get_number_hex(const char *optstr, const char *key, unsigned long *result);

bool
optstr_get_macaddr(const char *optstr, const char *key, uint8_t result[ETHER_ADDR_LEN]);

DESCRIPTION

An options string is a list of key/value pairs represented in textual form. Each pair is expressed as key=value and is separated from other pairs by one or more spaces. For example:

Options strings are used to pass information between userland programs and the kernel in a binary-agnostic way. This makes them endianness and ABI independent.

FUNCTIONS

The following functions are provided to manage options strings:

optstr_get(optstr, key, buf, bufsize)

Scans the optstr options string looking for the key key and stores its value in the buffer pointed to by buf copying a maximum of bufsize bytes. Returns ‘true’ if the key was found or ‘false’ otherwise, in which case buf is left unmodified.

The optstr_get_item family of functions provide the ability to scan for the key, and return the value converted to an appropriate type.

optstr_get_string(optstr, key, result)

 

optstr_get_number(optstr, key, result)

 

optstr_get_number_binary(optstr, key, result)

 

optstr_get_number_hex(optstr, key, result)

 

optstr_get_macaddr(optstr, key, result)

These functions scan the optstr options string looking for the key key and returns the key value converted as per the function name in result. All functions return ‘true’ if the key was found or ‘false’ otherwise, in which case result is left unmodified.

CODE REFERENCES

The options string management functions are implemented within the files sys/kern/subr_optstr.c and sys/sys/optstr.h.

HISTORY

Options strings appeared in NetBSD 4.0.