When I try to execute the exec ls, my putty session is getting closed. What is the difference between ls and exec ls ?
Why do we need the exec command, and what are the uses of this command ?
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perror
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user2720323
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Related: http://stackoverflow.com/a/18351547/1983854 – fedorqui Sep 12 '13 at 08:29
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possible duplicate of [What is the use of exec command in the shell scripting?](http://stackoverflow.com/questions/18351198/what-is-the-use-of-exec-command-in-the-shell-scripting) – Johan Sep 12 '13 at 09:38
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exec replaces the current process (the shell) with the new process. If you call a program without exec, the shell will fork a new process and then replace the new process with the program.
knittl
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exec is a shell built-in command.
In the manpage it says
If exec is specified with command, it shall replace the shell with command without creating a new process.
So when you execute exec ls in the shell, your shell will be replaced with the ls process; when this process ends, the shell exits. Compared with source or ., this could be useful in shell scripts.
