mirror of
https://github.com/rwxrob/bonzai
synced 2024-11-18 15:25:45 +00:00
91 lines
2.4 KiB
Go
91 lines
2.4 KiB
Go
/*
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Copyright 2022 Robert S. Muhlestein.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package bonzai
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import (
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"fmt"
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"log"
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"os"
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"strings"
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)
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// Method defines the main code to execute for a command (Cmd). By
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// convention the parameter list should be names "args" if there are
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// args expected and "none" if not. Methods must never write error
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// output to anything but standard error and should almost always use
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// the log package to do so.
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type Method func(args ...string) error
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// ----------------------- errors, exit, debug -----------------------
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// DoNotExit effectively disables Exit and ExitError allowing the
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// program to continue running, usually for test evaluation.
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var DoNotExit bool
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// ExitOff sets DoNotExit to false.
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func ExitOff() { DoNotExit = true }
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// ExitOn sets DoNotExit to true.
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func ExitOn() { DoNotExit = false }
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// Exit calls os.Exit(0) unless DoNotExit has been set to true. Cmds
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// should never call Exit themselves returning a nil error from their
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// Methods instead.
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func Exit() {
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if !DoNotExit {
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os.Exit(0)
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}
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}
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// ExitError prints err and exits with 1 return value unless DoNotExit
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// has been set to true. Commands should usually never call ExitError
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// themselves returning an error from their Method instead.
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func ExitError(err ...interface{}) {
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switch e := err[0].(type) {
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case string:
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if len(e) > 1 {
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log.Printf(e+"\n", err[1:]...)
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} else {
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log.Println(e)
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}
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case error:
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out := fmt.Sprintf("%v", e)
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if len(out) > 0 {
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log.Println(out)
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}
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}
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if !DoNotExit {
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os.Exit(1)
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}
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}
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// ArgsFrom returns a list of field strings split on space with an extra
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// trailing special space item appended if the line has any trailing
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// spaces at all signifying a definite word boundary and not a potential
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// prefix.
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func ArgsFrom(line string) []string {
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args := []string{}
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if line == "" {
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return args
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}
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args = strings.Fields(line)
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if line[len(line)-1] == ' ' {
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args = append(args, " ")
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}
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return args
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}
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