TYPEDOPTS(N)TYPEDOPTS(N)NAMEtypedopts - parse typed command-line options in TCL
SYNOPSIStypedopts arglist optlist optret argret rest [ options ]
OPTIONS-noinit
Don't initialize optret and argret.
DESCRIPTIONtypedopts is a command line option parser. It reads arglist and finds
all the options that are described in optlist. If no errors are found,
then typedopts will set rest to the command line arguments that weren't
parsed, optret and argret as described below, and return 1. optret and
argret will be set to arrays, indexed by the names of the options in
optlist. optret will contain boolean values indicating which options
were found in arglist, and argret will contain the arguments to the
options found.
optlist is a TCL list that describes all of the options that the pro‐
gram accepts. It consists of type-name pairs:
{ type name type name ... }
type describes what type of argument the option may take; the types are
described below. Some of the types require additional parameters; for
these types, type must be a TCL list with the type name followed by the
parameters.
name is the name of the option; if the program accepts more than one
option of type type, then name may be a TCL list of all the options of
that type. The option may be abbreviated on the command line, as long
as the abbreviation uniquely identifies one option.
The types for type are listed here. The type name in type may be a
unique abbreviation of the type name listed.
boolean
A simple flag; no argument is accepted for the option.
string A string -- no type checking is done.
float A floating point number. All of the TCL floating point formats
should be accepted for this.
integer
An integer.
number A floating point number or an integer.
one-of value...
One of a specific set of values. The values may be abbreviated
when used on the command line.
list-of type
A list of values of type type. The list ends when one of the
following is found: A valid command line option, the string
``--'', or the end of arglist.
multiple type
This option takes one argument of type type, but may appear more
than once on the command line. If an option is not specified as
being of type multiple then it may appear on the command line
only once.
If an option is of type list-of or multiple, then the value found for
that option in argret will be a TCL list of all the values found for
the option, in the order that they appeared on the command line.
If typedopts finds an option that is not described in optlist, or if it
finds an option argument of the wrong type, it will set argret(_ERROR_)
to an error message, set rest to the rest of the options and arguments,
and return 0.
If the -noinit option is given to typedopts, then the optret and argret
arrays will not be initialized. This allows the program to call type‐
dopts several times with different arglists without losing the informa‐
tion from previous calls.
If typedopts can't parse its options for any reason, it will fail with
an error message and return without modifying any other variables.
EXAMPLE:
The command line parser for a simple text formatter is given below.
The formatter accepts the options -top, -bottom, -left, -right, and
-paragraph to set the margins, -header to set the header string,
-pagenum to set the page number, and -position to position the page
number in the footer (the position can be left, right, or center). It
first parses arguments from the environment variable TFORMAT, then from
the command line. The command line can have options and filenames
intermixed; the options affect all files found after the option.
proc parseOpts { } {
# global variables needed: env = environ variables array,
# argv == command line args
global env argv
# The options list: (they have to be declared multiple, because we
# aren't re-initializing the option arrays each time.
set optlist {
{ multiple integer } { left right top bottom paragraph pagenum }
{ multiple string } header
{ multiple one-of left right center } position
}
# check if we have a $TFORMAT environment variable to parse
if { [ lsearch -exact [ array names $env ] "TFORMAT" ] > -1 } then {
# initialize the options arrays found() and values() with the values
# from TFORMAT
set list $env(TFORMAT)
while { ! [ typedopts $list $opts found values list ] } {
# error returned from typedopts: print the error message and
# continue parsing
puts stderr "Parsing \$TFORMAT: $values(_ERROR_)"
}
# check if there are any arguments left; if so, give a warning.
if { [ llength $list ] } then {
puts stderr "Warning: \$TFORMAT has non-option arguments!"
}
} else {
# initialize options arrays found() and values() from an empty list
typedopts { } $opts found values
}
# start parsing the command line. As long as its not empty, we first
# pass pass it through the option parser, then call the formatter on
# the files.
while { [ llength $argv ] } {
while { ! [ typedopts $argv $opts found values argv -noinit ] } {
puts stderr "$values(_ERROR_)"
}
format [ lindex $argv 0 ]
set argv [ lrange $argv 1 end ]
}
}
SEE ALSOgetopt(3)AUTHOR
Johnson Earls: darkfox@netcom.com.
BUGS
If an option has both multiple and list-of in its type, the muiltiple
part will only be effective if it comes first, e.g.
{ multiple list-of string }
but not
{ list-of multiple string }
Setting an option to type
{ multiple boolean }
will cause an infinite loop if the option occurs before non-option
arguments.
19 February 1994 TYPEDOPTS(N)
