mirror of
https://github.com/vbatts/go-mtree.git
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fbada2e081
This code was written before %w was added to Go, and there were a fair few mistakes in the copy-pasted error code. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
103 lines
3.4 KiB
Go
103 lines
3.4 KiB
Go
// SPDX-License-Identifier: Apache-2.0
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/*
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* govis: unicode aware vis(3) encoding implementation
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* Copyright (C) 2017-2025 SUSE LLC.
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*
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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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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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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 govis
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import (
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"errors"
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"fmt"
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"strconv"
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"strings"
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)
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// VisFlag manipulates how the characters are encoded/decoded
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type VisFlag uint
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// vis() has a variety of flags when deciding what encodings to use. While
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// mtree only uses one set of flags, implementing them all is necessary in
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// order to have compatibility with BSD's vis() and unvis() commands.
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const (
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VisOctal VisFlag = (1 << iota) // VIS_OCTAL: Use octal \ddd format.
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VisCStyle // VIS_CSTYLE: Use \[nrft0..] where appropriate.
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VisSpace // VIS_SP: Also encode space.
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VisTab // VIS_TAB: Also encode tab.
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VisNewline // VIS_NL: Also encode newline.
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VisSafe // VIS_SAFE: Encode unsafe characters.
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VisNoSlash // VIS_NOSLASH: Inhibit printing '\'.
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VisHTTPStyle // VIS_HTTPSTYLE: HTTP-style escape %xx.
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VisGlob // VIS_GLOB: Encode glob(3) magics.
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visMask VisFlag = (1 << iota) - 1 // Mask of all flags.
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VisWhite VisFlag = (VisSpace | VisTab | VisNewline)
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)
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// errUnknownVisFlagsError is a special value that lets you use [errors.Is]
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// with [unknownVisFlagsError]. Don't actually return this value, use
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// [unknownVisFlagsError] instead!
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var errUnknownVisFlagsError = errors.New("unknown or unsupported vis flags")
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// unknownVisFlagsError represents an error caused by unknown [VisFlag]s being
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// passed to [Vis] or [Unvis].
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type unknownVisFlagsError struct {
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flags VisFlag
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}
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func (err unknownVisFlagsError) Is(target error) bool {
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return target == errUnknownVisFlagsError
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}
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func (err unknownVisFlagsError) Error() string {
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return fmt.Sprintf("%s contains unknown or unsupported flags %s", err.flags, err.flags&^visMask)
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}
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// String pretty-prints VisFlag.
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func (vflags VisFlag) String() string {
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flagNames := []struct {
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name string
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bits VisFlag
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}{
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{"VisOctal", VisOctal},
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{"VisCStyle", VisCStyle},
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{"VisSpace", VisSpace},
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{"VisTab", VisTab},
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{"VisNewline", VisNewline},
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{"VisSafe", VisSafe},
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{"VisNoSlash", VisNoSlash},
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{"VisHTTPStyle", VisHTTPStyle},
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{"VisGlob", VisGlob},
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}
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var (
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flagSet = make([]string, 0, len(flagNames))
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seenBits VisFlag
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)
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for _, flag := range flagNames {
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if vflags&flag.bits == flag.bits {
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seenBits |= flag.bits
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flagSet = append(flagSet, flag.name)
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}
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}
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// If there were any remaining flags specified we don't know the name of,
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// just add them in an 0x... format.
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if remaining := vflags &^ seenBits; remaining != 0 {
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flagSet = append(flagSet, "0x"+strconv.FormatUint(uint64(remaining), 16))
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}
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if len(flagSet) == 0 {
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return "0"
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}
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return strings.Join(flagSet, "|")
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}
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