common/man/stropt.3

        .fp 5 CW
..
.nr ;G \\n(.f
.Af "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9"
\\*(;G
..
.aF 5 \\n(.f "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"
..
.aF 5 1 "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"
..
.aF 1 5 "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"
..


 0
..


..
 STROPT 3
 NAME
stropt - table driven option expression evaluator
 SYNOPSIS
.L "#include <namval.h>"

.L "int stropt(char* s, struct namval* tab,

.L " int (*fun)(void* a, struct namval* p, int n, char* v),"

.L " void* a)"
 DESCRIPTION
 stropt parses option expressions in the nul-terminated string
 s using the option names in
 tab .  tab is an array of
 "struct namval" name value pairs:
.EX
char* name;
int value;

The last entry must be followed by a sentinel with
 name set to 0.

An option expression contains 0 or more of [no]name[=value]
separate by
 space or
 tab , where
 name must be one of the option names in
 tab ,  value  is an optional value, and
 no is for Boolean options.
Each option is passed to
 fun for processing.
 a is the
.L void*
pointer that is passed from the
 stropt call but is otherwise not interpreted.
 p points to the option name value pair from
 tab .  n is 0 if
 no preceeded the option
 name and
 v points to the beginning of the option
 value in
 s . and
If
 name is not found in
 tab then
 fun is called with
 p pointing to an internal
 namval entry with
 p->name pointing to the unknown option and
 p->value set to the
 value of the sentinel entry in
 tab .
If
 fun returns non-zero then this value is returned and no further
options are processed.
Otherwise
 stropt returns 0 after processing all options.