diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js new file mode 100755 index 000000000..287b29148 --- /dev/null +++ b/implement-shell-tools/cat/cat.js @@ -0,0 +1,59 @@ +#!/usr/bin/env node + +const fs = require('fs'); +const path = require('path'); + +function cat(files, options) { + let lineNumber = 1; + + files.forEach((file) => { + try { + const data = fs.readFileSync(file, 'utf8'); + const lines = data.split('\n'); + + lines.forEach((line) => { + const prefix = options.numberNonEmpty && line.trim() ? `${lineNumber}\t` : options.numberLines ? `${lineNumber}\t` : ''; + console.log(`${prefix}${line}`); + if (prefix) lineNumber++; + }); + } catch (err) { + if (err.code === 'ENOENT') { + console.error(`cat: ${file}: No such file or directory`); + } else if (err.code === 'EACCES') { + console.error(`cat: ${file}: Permission denied`); + } else { + console.error(`cat: ${file}: An error occurred`); + } + process.exit(1); + } + }); +} + +function main() { + const args = process.argv.slice(2); + const options = { + numberLines: false, + numberNonEmpty: false, + }; + + const files = []; + + args.forEach((arg) => { + if (arg === '-n') { + options.numberLines = true; + } else if (arg === '-b') { + options.numberNonEmpty = true; + } else { + files.push(arg); + } + }); + + if (files.length === 0) { + console.error('Usage: node cat.js [-n | -b] ...'); + process.exit(1); + } + + cat(files, options); +} + +main(); \ No newline at end of file diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js new file mode 100644 index 000000000..b2587e30d --- /dev/null +++ b/implement-shell-tools/ls/ls.js @@ -0,0 +1,48 @@ +#!/usr/bin/env node + +const fs = require('fs'); + +function listFiles(directory, options) { + try { + const files = fs.readdirSync(directory, { withFileTypes: true }); + + files.forEach((file) => { + if (!options.all && file.name.startsWith('.')) { + return; // Skip hidden files unless -a is specified + } + console.log(`${directory}/${file.name}`); + }); + } catch (err) { + console.error(`ls: cannot access '${directory}': ${err.code === 'ENOENT' ? 'No such file or directory' : 'An error occurred'}`); + process.exit(1); + } +} + +function main() { + const args = process.argv.slice(2); + const options = { + all: false, + }; + + const directories = []; + + args.forEach((arg) => { + if (arg === '-1') { + // -1 is the default behavior, so no action needed + } else if (arg === '-a') { + options.all = true; + } else { + directories.push(arg); + } + }); + + if (directories.length === 0) { + directories.push('.'); + } + + directories.forEach((directory) => { + listFiles(directory, options); + }); +} + +main(); \ No newline at end of file diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js new file mode 100644 index 000000000..e807112ce --- /dev/null +++ b/implement-shell-tools/wc/wc.js @@ -0,0 +1,57 @@ +#!/usr/bin/env node + +const fs = require('fs'); + +function countFile(file, options) { + try { + const data = fs.readFileSync(file, 'utf8'); + + const lines = data.split('\n').length; + const words = data.split(/\s+/).filter(Boolean).length; + const bytes = Buffer.byteLength(data, 'utf8'); + + const results = []; + if (options.lines) results.push(lines); + if (options.words) results.push(words); + if (options.bytes) results.push(bytes); + + console.log(`${results.join('\t')}\t${file}`); + } catch (err) { + console.error(`wc: ${file}: ${err.code === 'ENOENT' ? 'No such file or directory' : 'An error occurred'}`); + process.exit(1); + } +} + +function main() { + const args = process.argv.slice(2); + const options = { + lines: false, + words: false, + bytes: false, + }; + + const files = []; + + args.forEach((arg) => { + if (arg === '-l') { + options.lines = true; + } else if (arg === '-w') { + options.words = true; + } else if (arg === '-c') { + options.bytes = true; + } else { + files.push(arg); + } + }); + + if (files.length === 0) { + console.error('Usage: wc [-l | -w | -c] ...'); + process.exit(1); + } + + files.forEach((file) => { + countFile(file, options); + }); +} + +main(); \ No newline at end of file