erik/dcat
erik/dcat
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Split into library.

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Erik C. Thauvin 2021-10-10 00:57:12 -07:00
parent c21191160f
commit a29d8130a9
3 changed files with 145 additions and 132 deletions
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119
bin/dcat.dart
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@ -1,16 +1,15 @@
// Copyright (c) 2021, Erik C. Thauvin. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be found
// in the LICENSE file.
import 'dart:convert';
import 'dart:io';
import 'package:args/args.dart';
import 'package:dcat/dcat.dart';
import 'package:indent/indent.dart';
const appName = 'dcat';
const appName = libName;
const appVersion = '1.0.0';
const exitFailure = 1;
const exitSuccess = 0;
const helpFlag = 'help';
const nonBlankFlag = 'number-nonblank';
const numberFlag = 'number';
@ -19,69 +18,9 @@ const showTabsFlag = 'show-tabs';
const squeezeBlank = 'squeeze-blank';
const versionFlag = 'version';
/// Prints [message] and [path] to stderr.
Future<int> handleError(String message, {String path = ''}) async {
if (path.isNotEmpty) {
stderr.writeln('$appName: $path: $message');
} else {
stderr.write('$appName: $message');
}
return exitFailure;
}
/// Concatenates files in [paths].
Future<int> cat(List<String> paths,
{List<String>? log,
bool showEnds = false,
bool numberNonBlank = false,
bool showLineNumbers = false,
bool showTabs = false,
bool squeezeBlank = false}) async {
var lineNumber = 1;
var returnCode = 0;
log?.clear();
if (paths.isEmpty) {
final lines = await _readStdin();
await _writeLines(lines, lineNumber, log, showEnds, showLineNumbers,
numberNonBlank, showTabs, squeezeBlank);
} else {
for (final path in paths) {
try {
final Stream<String> lines;
if (path == '-') {
lines = await _readStdin();
} else {
lines = utf8.decoder
.bind(File(path).openRead())
.transform(const LineSplitter());
}
lineNumber = await _writeLines(lines, lineNumber, log, showEnds,
showLineNumbers, numberNonBlank, showTabs, squeezeBlank);
} on FileSystemException catch (e) {
final String? osMessage = e.osError?.message;
final String message;
if (osMessage != null && osMessage.isNotEmpty) {
message = osMessage;
} else {
message = e.message;
}
returnCode = await handleError(message, path: path);
} on FormatException {
returnCode =
await handleError('Binary file not supported.', path: path);
} catch (e) {
returnCode = await handleError(e.toString(), path: path);
}
}
}
return returnCode;
}
/// Concatenates files specified in [arguments].
///
/// ```
/// dcat [OPTION]... [FILE]...
/// ```
/// Usage: `dcat [OPTION]... [FILE]...`
Future<int> main(List<String> arguments) async {
final parser = ArgParser();
Future<int> returnCode;
@ -109,8 +48,9 @@ Future<int> main(List<String> arguments) async {
try {
argResults = parser.parse(arguments);
} on FormatException catch (e) {
return await handleError(
"${e.message}\nTry '$appName --$helpFlag' for more information.");
return await printError(
"${e.message}\nTry '$appName --$helpFlag' for more information.",
appName: appName);
}
if (argResults[helpFlag]) {
@ -131,21 +71,17 @@ Future<int> main(List<String> arguments) async {
return exitCode;
}
/// Prints version info.
/// Prints the version info.
Future<int> printVersion() async {
print('''$appName (Dart cat) $appVersion
Copyright (C) 2021 Erik C. Thauvin
License: 3-Clause BSD <https://opensource.org/licenses/BSD-3-Clause>
Based on <https://dart.dev/tutorials/server/cmdline>
Inspired by <https://dart.dev/tutorials/server/cmdline>
Written by Erik C. Thauvin <https://erik.thauvin.net/>''');
return exitSuccess;
}
/// Reads from stdin.
Future<Stream<String>> _readStdin() async =>
stdin.transform(utf8.decoder).transform(const LineSplitter());
/// Prints usage with [options].
Future<int> usage(String options) async {
print('''Usage: $appName [OPTION]... [FILE]...
@ -161,40 +97,3 @@ Examples:
Source and documentation: <https://github.com/ethauvin/dcat>''');
return exitSuccess;
}
/// Writes lines to stdout.
Future<int> _writeLines(Stream<String> lines, int lineNumber,
[List<String>? log,
bool showEnds = false,
bool showLineNumbers = false,
bool showNonBlank = false,
bool showTabs = false,
bool sqeezeBlank = false]) async {
var emptyLine = 0;
final sb = StringBuffer();
await for (final line in lines) {
sb.clear();
if (sqeezeBlank && line.isEmpty) {
if (++emptyLine >= 2) {
continue;
}
} else {
emptyLine = 0;
}
if (showNonBlank || showLineNumbers) {
sb.write('${lineNumber++}: ');
}
if (showTabs) {
sb.write(line.replaceAll('\t', '^I'));
} else {
sb.write(line);
}
if (showEnds) {
sb.write('\$');
}
log?.add(sb.toString());
stdout.writeln(sb);
}
return lineNumber;
}