mirror of
https://github.com/vbatts/go-mtree.git
synced 2025-10-03 20:21:01 +00:00
bd7b72e037
This is supported by both OpenBSD and FreBSD so it seems possible that we will run into \" sequences at some point. The handling is basically identical to \\ sequences. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
104 lines
3.5 KiB
Go
104 lines
3.5 KiB
Go
// SPDX-License-Identifier: Apache-2.0
|
|
/*
|
|
* govis: unicode aware vis(3) encoding implementation
|
|
* Copyright (C) 2017-2025 SUSE LLC.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
package govis
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
// VisFlag manipulates how the characters are encoded/decoded
|
|
type VisFlag uint
|
|
|
|
// vis() has a variety of flags when deciding what encodings to use. While
|
|
// mtree only uses one set of flags, implementing them all is necessary in
|
|
// order to have compatibility with BSD's vis() and unvis() commands.
|
|
const (
|
|
VisOctal VisFlag = (1 << iota) // VIS_OCTAL: Use octal \ddd format.
|
|
VisCStyle // VIS_CSTYLE: Use \[nrft0..] where appropriate.
|
|
VisSpace // VIS_SP: Also encode space.
|
|
VisTab // VIS_TAB: Also encode tab.
|
|
VisNewline // VIS_NL: Also encode newline.
|
|
VisSafe // VIS_SAFE: Encode unsafe characters.
|
|
VisNoSlash // VIS_NOSLASH: Inhibit printing '\'.
|
|
VisHTTPStyle // VIS_HTTPSTYLE: HTTP-style escape %xx.
|
|
VisGlob // VIS_GLOB: Encode glob(3) magics.
|
|
VisDoubleQuote // VIS_DQ: Encode double-quotes (").
|
|
visMask VisFlag = (1 << iota) - 1 // Mask of all flags.
|
|
|
|
VisWhite VisFlag = (VisSpace | VisTab | VisNewline)
|
|
)
|
|
|
|
// errUnknownVisFlagsError is a special value that lets you use [errors.Is]
|
|
// with [unknownVisFlagsError]. Don't actually return this value, use
|
|
// [unknownVisFlagsError] instead!
|
|
var errUnknownVisFlagsError = errors.New("unknown or unsupported vis flags")
|
|
|
|
// unknownVisFlagsError represents an error caused by unknown [VisFlag]s being
|
|
// passed to [Vis] or [Unvis].
|
|
type unknownVisFlagsError struct {
|
|
flags VisFlag
|
|
}
|
|
|
|
func (err unknownVisFlagsError) Is(target error) bool {
|
|
return target == errUnknownVisFlagsError
|
|
}
|
|
|
|
func (err unknownVisFlagsError) Error() string {
|
|
return fmt.Sprintf("%s contains unknown or unsupported flags %s", err.flags, err.flags&^visMask)
|
|
}
|
|
|
|
// String pretty-prints VisFlag.
|
|
func (vflags VisFlag) String() string {
|
|
flagNames := []struct {
|
|
name string
|
|
bits VisFlag
|
|
}{
|
|
{"VisOctal", VisOctal},
|
|
{"VisCStyle", VisCStyle},
|
|
{"VisSpace", VisSpace},
|
|
{"VisTab", VisTab},
|
|
{"VisNewline", VisNewline},
|
|
{"VisSafe", VisSafe},
|
|
{"VisNoSlash", VisNoSlash},
|
|
{"VisHTTPStyle", VisHTTPStyle},
|
|
{"VisGlob", VisGlob},
|
|
}
|
|
var (
|
|
flagSet = make([]string, 0, len(flagNames))
|
|
seenBits VisFlag
|
|
)
|
|
for _, flag := range flagNames {
|
|
if vflags&flag.bits == flag.bits {
|
|
seenBits |= flag.bits
|
|
flagSet = append(flagSet, flag.name)
|
|
}
|
|
}
|
|
// If there were any remaining flags specified we don't know the name of,
|
|
// just add them in an 0x... format.
|
|
if remaining := vflags &^ seenBits; remaining != 0 {
|
|
flagSet = append(flagSet, "0x"+strconv.FormatUint(uint64(remaining), 16))
|
|
}
|
|
if len(flagSet) == 0 {
|
|
return "0"
|
|
}
|
|
return strings.Join(flagSet, "|")
|
|
}
|