fix(terminal): skip -l login flag for csh and tcsh

[serhiizghama]

Problem

When $SHELL is set to tcsh (or csh), every terminal command issued by Continue fails immediately:

Unknown option: `-l'
Usage: tcsh [ -bcdefilmnqstvVxX ] [ argument ... ].
Command failed with exit code 1

getShellCommand in both core/tools/implementations/runTerminalCommand.ts and extensions/cli/src/tools/runTerminalCommand.ts hardcodes ["-l", "-c", command] for every Unix shell. csh and tcsh do not accept -l as a flag, so the shell rejects the invocation before the command is ever evaluated.

Fixes #12378.

Solution

Detect the shell binary name (basename of $SHELL) and omit the -l flag when it is csh or tcsh. Those shells automatically source ~/.cshrc / ~/.tcshrc on every invocation, so the login-shell intent (sourcing rc files) is preserved without the flag.

Behavior is unchanged for bash, zsh, sh, fish, and any other shell — they continue to receive -l -c <command>.

Testing

• bash / zsh: getShellCommand("echo hi") returns args: ["-l", "-c", "echo hi"] (unchanged).
• tcsh / csh: getShellCommand("echo hi") returns args: ["-c", "echo hi"], which tcsh -c "echo hi" accepts and runs normally.
• Manual repro from the issue ($SHELL=/bin/tcsh, ask Continue to run pwd) now succeeds instead of erroring with Unknown option: -l.

---

Summary by cubic

Skip the -l login flag when invoking csh/tcsh so terminal commands don’t fail with “Unknown option: -l.” Other shells keep using -l -c to load shell configs.

• Bug Fixes
  • Detect the shell name and omit -l for csh/tcsh, which auto-source their rc files.
  • Added a small helper to compute login args and applied it in both terminal command implementations (Unix/macOS and WSL paths); bash/zsh behavior unchanged.

^{Written for commit 1ae4cab. Summary will update on new commits.}

[github-actions]

Thank you for your submission, we really appreciate it. Like many open-source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution. You can sign the CLA by just posting a Pull Request Comment same as the below format.

---

I have read the CLA Document and I hereby sign the CLA

---

_{You can retrigger this bot by commenting recheck in this Pull Request. Posted by the CLA Assistant Lite bot.}

[cubic-dev-ai]

No issues found across 2 files