OPTSTR(9)

OPTSTR(9) | Kernel Developer's Manual | OPTSTR(9)

# NAME

`optstr_get` —
Options string management

# SYNOPSIS

`#include <sys/optstr.h>`

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

# 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:

    key1=value1 key2=value2 key3=value3

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.

# 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.

August 11, 2007 | NetBSD 10.0