London | 26-Jul-SDC | Roman Sanaye | Sprint 3 | Implement Shell Tools

implement-shell-tools/cat/README.md

@@ -6,11 +6,11 @@ Your task is to implement your own version of `cat`.
 
 It must act the same as `cat` would, if run from the directory containing this README.md file, for the following command lines:
 
-* `cat sample-files/1.txt`
-* `cat -n sample-files/1.txt`
-* `cat sample-files/*.txt`
-* `cat -n sample-files/*.txt`
-* `cat -b sample-files/3.txt`
+- `cat sample-files/1.txt`
+- `cat -n sample-files/1.txt`
+- `cat sample-files/*.txt`
+- `cat -n sample-files/*.txt`
+- `cat -b sample-files/3.txt`
 
 Matching any additional behaviours or flags are optional stretch goals.
 

implement-shell-tools/cat/cat.js

@@ -0,0 +1,47 @@
+const fs = require("fs");
+
+const args = process.argv.slice(2);
+
+let flag = "";
+let filePaths = [];
+
+if (args[0] && args[0].startsWith("-")) {
+  flag = args[0];
+  filePaths = args.slice(1);
+} else {
+  filePaths = args;
+}
+
+// Read all files into one string
+let content = filePaths.map((file) => fs.readFileSync(file, "utf-8")).join("");
+
+// Split into lines
+let lines = content.split(/\r?\n/);
+
+// Remove the last empty line if the file ends with a newline
+if (lines[lines.length - 1] === "") {
+  lines.pop();
+}
+
+// Handle flag ==> -n adding number to the line;
+if (flag === "-n") {
+  lines = lines.map((line, index) => {
+    return `${index + 1}  ${line}`;
+  });
+}
+
+// Handle flag ==> -b avoids adding number to empty line
+if (flag === "-b") {
+  let lineNumber = 1;
+
+  lines = lines.map((line) => {
+    if (line.trim() === "") {
+      return line;
+    }
+
+    return `${lineNumber++}  ${line}`;
+  });
+}
+
+process.stdout.write(lines.join("\n"));
+

implement-shell-tools/ls/ls.js

@@ -0,0 +1,40 @@
+const fs = require("fs");
+
+const args = process.argv.slice(2);
+
+let flags = [];
+let paths = [];
+
+// Check arguments: separate flags and paths
+args.forEach((arg) => {
+  if (arg.startsWith("-")) {
+    flags.push(arg);
+  } else {
+    paths.push(arg);
+  }
+});
+
+// If no path is provided, use the current directory
+if (paths.length === 0) {
+  paths = ["."];
+}
+
+paths.forEach((path) => {
+  if (fs.statSync(path).isFile()) {
+    console.log(path);
+  } else {
+    let contents = fs.readdirSync(path);
+
+    // Hide hidden files unless -a exists
+    if (!flags.includes("-a")) {
+      contents = contents.filter((file) => !file.startsWith("."));
+    }
+
+    // Check -1 flag
+    if (flags.includes("-1")) {
+      console.log(contents.join("\n"));
+    } else {
+      console.log(contents.join(" "));
+    }
+  }
+});

implement-shell-tools/wc/wc.js

@@ -0,0 +1,73 @@
+// Power shell commands with Js codes
+
+const fs = require("fs");
+const args = process.argv.slice(2);
+
+let flags = [];
+let paths = [];
+
+// Check arguments: separate flags and paths
+args.forEach((arg) => {
+  if (arg.startsWith("-")) {
+    flags.push(arg);
+  } else {
+    paths.push(arg);
+  }
+});
+
+let totalLines = 0;
+let totalWords = 0;
+let totalCharacters = 0;
+
+paths.forEach((file) => {
+  const content = fs.readFileSync(file, "utf-8");
+
+  const lines = content.split("\n").length - 1;
+  const words = content.trim().split(/\s+/).length;
+  const chars = content.length;
+
+  if (flags.length === 0) {
+    console.log(lines, words, chars, file);
+  } else {
+    let output = [];
+
+    if (flags.includes("-l")) {
+      output.push(lines);
+    }
+
+    if (flags.includes("-w")) {
+      output.push(words);
+    }
+
+    if (flags.includes("-c")) {
+      output.push(chars);
+    }
+
+    console.log(...output, file);
+  }
+
+  totalLines += lines;
+  totalWords += words;
+  totalCharacters += chars;
+});
+if (paths.length > 1) {
+  let totalOutput = [];
+
+  if (flags.length === 0) {
+    totalOutput.push(totalLines, totalWords, totalCharacters);
+  } else {
+    if (flags.includes("-l")) {
+      totalOutput.push(totalLines);
+    }
+
+    if (flags.includes("-w")) {
+      totalOutput.push(totalWords);
+    }
+
+    if (flags.includes("-c")) {
+      totalOutput.push(totalCharacters);
+    }
+  }
+
+  console.log(...totalOutput, "total");
+}