[Linux] C Shell (csh) killall用法: Terminate processes by name

Overview

The killall command in C Shell (csh) is used to terminate all processes that match a specified name. This command is particularly useful for managing multiple instances of a program without needing to find and kill each process individually.

Usage

The basic syntax of the killall command is as follows:

killall [options] [arguments]

Common Options

• -u <user>: Only kill processes owned by the specified user.
• -s <signal>: Specify the signal to send to the processes (e.g., -s TERM to send the terminate signal).
• -q: Suppress error messages for processes that do not exist.
• -I: Ignore case when matching process names.

Common Examples

Here are some practical examples of using the killall command:

1. Terminate all instances of a program:

   killall firefox
   

   This command will kill all running instances of Firefox.

2. Send a specific signal to a process:

   killall -s TERM myapp
   

   This sends the terminate signal to all instances of myapp.

3. Kill processes owned by a specific user:

   killall -u username
   

   This will terminate all processes owned by username.

4. Suppress error messages:

   killall -q myapp
   

   This will attempt to kill myapp without displaying errors if it is not running.

5. Ignore case when killing processes:

   killall -I myapp
   

   This will kill all processes matching myapp, regardless of case.

Tips

• Always double-check the process name you are targeting to avoid accidentally terminating the wrong processes.
• Use the -q option if you want to avoid cluttering your terminal with error messages when a process is not found.
• Consider using ps or pgrep to list processes before using killall to ensure you are terminating the correct ones.