added environment on terminal header and fixed agent behavior to detect shell

Author: PramaYudhistira

codex-cli/src/components/chat/terminal-header.tsx

@@ -15,6 +15,7 @@ export interface TerminalHeaderProps {
   agent?: AgentLoop;
   initialImagePaths?: Array<string>;
   flexModeEnabled?: boolean;
+  environment?: string;
 }
 
 const TerminalHeader: React.FC<TerminalHeaderProps> = ({
@@ -28,7 +29,36 @@ const TerminalHeader: React.FC<TerminalHeaderProps> = ({
   agent,
   initialImagePaths,
   flexModeEnabled = false,
+  environment,
 }) => {
+  const envName =
+    environment ??
+    (() => {
+      // check for Windows
+      if (process.platform === "win32") {
+        const msystem = process.env["MSYSTEM"];
+        // Check git bash
+        if (msystem && msystem.toLowerCase().includes("mingw")) {
+          return "Git Bash";
+        }
+
+        const keys = Object.keys(process.env).map((k) => k.toLowerCase());
+        // Check pwsh vs powershell
+        if (keys.includes("psedition")) {
+          return "PowerShell Core";
+        }
+        // Check for PowerShell
+        if (keys.includes("psmodulepath")) {
+          return "PowerShell";
+        }
+
+        const comspec = process.env["ComSpec"];
+        return comspec ? path.basename(comspec) : "cmd";
+      }
+
+      const shell = process.env["SHELL"];
+      return shell ? path.basename(shell) : "sh";
+    })();
   return (
     <>
       {terminalRows < 10 ? (
@@ -37,6 +67,7 @@ const TerminalHeader: React.FC<TerminalHeaderProps> = ({
           ● Codex v{version} - {PWD} - {model} ({provider}) -{" "}
           <Text color={colorsByPolicy[approvalPolicy]}>{approvalPolicy}</Text>
           {flexModeEnabled ? " - flex-mode" : ""}
+          {` - environment: ${envName}`}
         </Text>
       ) : (
         <>
@@ -71,6 +102,10 @@ const TerminalHeader: React.FC<TerminalHeaderProps> = ({
               <Text color="blueBright">↳</Text> provider:{" "}
               <Text bold>{provider}</Text>
             </Text>
+            <Text dimColor>
+              <Text color="blueBright">↳</Text> environment:{" "}
+              <Text bold>{envName}</Text>
+            </Text>
             <Text dimColor>
               <Text color="blueBright">↳</Text> approval:{" "}
               <Text bold color={colorsByPolicy[approvalPolicy]}>

codex-cli/src/utils/agent/agent-loop.ts

@@ -18,6 +18,7 @@ import {
   getApiKey,
   getBaseUrl,
 } from "../config.js";
+import { detectShell } from "../detect-shell.js";
 import { log } from "../logger/log.js";
 import { parseToolCallArguments } from "../parsers.js";
 import { responsesCreateViaChatCompletions } from "../responses.js";
@@ -1459,8 +1460,33 @@ export class AgentLoop {
   }
 }
 
+// Determine shell environment for command formatting guidance
+const shellEnv = detectShell().environment;
+const shellInstruction = /PowerShell/i.test(shellEnv)
+  ? `On Windows PowerShell, to correctly capture the working directory, please choose the one that is most appropriate:
+  - Drop into CMD: "cmd /C cd"
+  - Or stay in PowerShell but pipe through Out-String: "Get-Location | Out-String"
+  - Or use Write-Output (Get-Location).Path`
+  : /cmd/i.test(shellEnv)
+    ? `To determine the current working directory, run "cmd /C cd".`
+    : `To determine the current working directory, run "pwd".`;
+
 const prefix = `You are operating as and within the Codex CLI, a terminal-based agentic coding assistant built by OpenAI. It wraps OpenAI models to enable natural language interaction with a local codebase. You are expected to be precise, safe, and helpful.
 
+All commands should be formatted for: ${shellEnv}.
+${shellInstruction}
+
+When inspecting the filesystem, you MUST adhere to the following procedure:
+- Always begin by printing the current working directory (cwd) with the appropriate shell command:
+  - For PowerShell: Get-Location | Out-String, cmd /C cd, or (Get-Location).Path, whichever is most appropriate.
+  - For CMD: cmd /C cd
+  - For *nix shells: pwd
+- Then, explicitly cd into the repo root if needed, or set the working directory (workdir) in your tool calls to ensure you are operating from the repo root.
+- Normalize on a single listing command to view files:
+  - Use ls -a on *nix
+  - Use dir /a /b on Windows
+- Only proceed with reading or editing files after you have confirmed you are at the correct root location.
+
 You can:
 - Receive user prompts, project context, and files.
 - Stream responses and emit function calls (e.g., shell commands, code edits).

codex-cli/src/utils/detect-shell.ts

@@ -0,0 +1,80 @@
+import type { ParseEntry } from "shell-quote";
+
+import { spawnSync } from "child_process";
+import os from "os";
+import path from "path";
+import { parse } from "shell-quote";
+
+export interface ShellDetection {
+  shellOption?: boolean | string;
+  environment: string;
+}
+
+function requiresShell(cmd: Array<string>): boolean {
+  if (cmd.length === 1 && cmd[0]) {
+    const tokens = parse(cmd[0]) as Array<ParseEntry>;
+    return tokens.some((t) => typeof t === "object" && "op" in t);
+  }
+  return false;
+}
+
+export function detectShell(cmd?: Array<string>): ShellDetection {
+  const override = process.env["CODEX_SHELL"];
+  if (override) {
+    return { shellOption: override, environment: path.basename(override) };
+  }
+
+  // Windows
+  if (os.platform() === "win32") {
+    // Check git bash
+    const msystem = process.env["MSYSTEM"];
+    if (msystem && /mingw/i.test(msystem)) {
+      return { shellOption: "bash.exe", environment: "Git Bash" };
+    }
+    // Check pwsh vs powershell
+    const keys = Object.keys(process.env).map((k) => k.toLowerCase());
+    if (keys.includes("psedition")) {
+      return { shellOption: "pwsh.exe", environment: "PowerShell Core" };
+    }
+    if (keys.includes("psmodulepath")) {
+      return { shellOption: "powershell.exe", environment: "PowerShell" };
+    }
+    // Fallback to parent process
+    try {
+      const out =
+        spawnSync("tasklist", ["/fi", `PID eq ${process.ppid}`, "/nh"], {
+          encoding: "utf8",
+        }).stdout?.trim() || "";
+      const exe = out.split(/\s+/)[0]?.toLowerCase();
+      if (exe === "bash.exe") {
+        return { shellOption: "bash.exe", environment: "Git Bash" };
+      }
+      if (exe === "pwsh.exe") {
+        return { shellOption: "pwsh.exe", environment: "PowerShell Core" };
+      }
+      if (exe === "powershell.exe") {
+        return { shellOption: "powershell.exe", environment: "PowerShell" };
+      }
+    } catch {
+      console.warn("Failed to detect parent process shell");
+    }
+    // 4) final fallback
+    const com = process.env["ComSpec"];
+    return {
+      shellOption: com || true,
+      environment: com ? path.basename(com) : "cmd",
+    };
+  }
+
+  // UNIX‑like
+  let shellOption: boolean | string | undefined;
+  // Check if the command requires a shell
+  if (cmd && requiresShell(cmd)) {
+    shellOption = process.env["SHELL"] || true;
+  }
+  const shellEnv = process.env["SHELL"] || "";
+  const base = path.basename(shellEnv);
+  const envName =
+    base === "bash" ? "Bash" : base === "zsh" ? "Zsh" : base || "sh";
+  return { shellOption, environment: envName };
+}