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exec() Without fork()

Question Text​

We type the following command:

student@os:~$ ls

Why does the shell NOT simply call exec("/bin/ls")?

Bash exec

Question Answers​

  • Because /bin/ls may be buggy or vulnerable and compromise the shell
  • Because when ls ends, the shell is closed

  • Because the ls and bash processes must not share the same address space

  • Because bash needs to pass data to the ls process

Feedback​

If the shell simply execs "/bin/ls", the bash process is entirely replaced by the ls process. Therefore, when the ls process ends, the old bash process is no more and the terminal closes. This way, each command would close the terminal.