TCL：使用cmdline软件包中的"help"选项

Question

在我的TCL脚本中，我试图提供将使用"cmdline"包解析的输入参数。我在脚本中定义了以下内容：

set run_options {
{input_1.arg 8 "first input argument"}
{input_2.arg 1 "second input argument"}
{msb  "choose it if input data has msb first"}
{lsb  "choose it if input data has lsb first"}
}
set my_usage ": n tclsh my_src [options] ...noptions are:"
if {[catch {array set params [::cmdline::getoptions argv $run_options $my_usage]} msg]} {
puts "Error while parsing user options of $msg"
exit 1
}

一切看起来都很好，只是当运行我的脚本时，我发现"cmdline"包定义了"；帮助；选项，但当我使用"-帮助；选项以下是输出：

Error while parsing user options of my_src : 
tclsh my_src [options] ...
options are:
-input_1 value       first input argument <8>
-input_2 value       second input argument <1>
-msb                 choose it if input data has msb first
-lsb                 choose it if input data has lsb first
--                   Forcibly stop option processing
-help                Print this message
-?                   Print this message

那么，有人知道如何使用这个自动添加的"；帮助；选项而不给出错误消息？

Answer 1

cmdline::getoptions不会区分-help和未知选项(未识别的选项将被视为-?(。若您想对这两种情况有不同的消息，您需要在循环中直接使用其中一个较低级别的函数，或者类似于以下cmdline::getoptions的增强版本：

#!/usr/bin/env tclsh
package require try ;# In case you're still using tcl 8.5 for some reason
package require cmdline 1.5
proc better_getoptions {arglistVar optlist usage} {
upvar 1 $arglistVar argv
# Warning: Internal cmdline function
set opts [::cmdline::GetOptionDefaults $optlist result]
while {[set err [::cmdline::getopt argv $opts opt arg]]} {
if {$err < 0} {
return -code error -errorcode {CMDLINE ERROR} $arg
}
set result($opt) $arg
}
if {[info exists result(?)] || [info exists result(help)]} {
return -code error -errorcode {CMDLINE USAGE} 
[::cmdline::usage $optlist $usage]
}
return [array get result]
}
set run_options {
{input_1.arg 8 "first input argument"}
{input_2.arg 1 "second input argument"}
{msb  "choose it if input data has msb first"}
{lsb  "choose it if input data has lsb first"}
}
set my_usage ": n tclsh my_src [options] ...noptions are:"
try {
array set params [better_getoptions argv $run_options $my_usage]
puts "All options valid"
} trap {CMDLINE USAGE} {msg} {
puts stderr $msg
exit 0
} trap {CMDLINE ERROR} {msg} {
puts stderr "Error: $msg"
exit 1
}

示例用法：

$ ./example.tcl --help
cmd : 
tclsh my_src [options] ...
options are:
-input_1 value       first input argument <8>
-input_2 value       second input argument <1>
-msb                 choose it if input data has msb first
-lsb                 choose it if input data has lsb first
--                   Forcibly stop option processing
-help                Print this message
-?                   Print this message
$ ./example.tcl -foo
Error: Illegal option "-foo"
$ ./example.tcl -input_1
Error: Option "input_1" requires an argument
$ ./example.tcl -msb
All options valid