What is csh on Mac?
csh (C shell) · seed · quit hint: caution
csh is a macOS process (listed here as csh (C shell)). People usually find it in Activity Monitor when asking “what is this process?”
What does csh do?
C shell (csh) — Apple still ships /bin/csh as an acceptable shell in /etc/shells for legacy accounts and scripts. On current macOS, /bin/csh is a hard link to the same binary as /bin/tcsh (TENEX C shell); the basename reflects how it was invoked (argv0). Rare as a default UserShell today, but still appears for #!/bin/csh scripts, university/lab legacy profiles, and users who never migrated off csh. Syntax differs sharply from bash/zsh (set vs export, foreach, different redirection). Quitting closes that session like any interactive shell — prefer exit over force-kill if jobs are running. Prefer matching path /bin/csh so a random third-party ‘csh’ binary is not mislabeled.
When to leave csh running
- interactive-shell-session
- foreground-job-running
Is it safe to quit csh?
Hint: caution. SystemWoe Free and Pro use keep-guards so you don’t blindly kill something important — Pro adds force-terminate only with confirmation.
Further reading
Related system processes on Mac
- What is AccessibilityUIServer on Mac? · Accessibility UI Server
- What is com.apple.appkit.xpc.ThemeWidgetControlViewService on Mac? · AppKit theme widget view service
- What is com.apple.systempreferences.AppleIDSettings on Mac? · Apple Account Settings
- What is AquaAppearanceHelper on Mac? · Aqua Appearance Helper
- What is AudioConverterHardenedService on Mac? · Hardened Audio Converter service
- What is com.apple.quicklook.thumbnail.AudiovisualExtension on Mac? · Audiovisual Quick Look thumbnails