Dealing with Signals

A program can deal with a signal in three ways:

  • Do nothing and let the default action occur. This is the simplest method for a program to deal with a signal because it requires no extra code.

  • Ignore the signal and continue executing. This method is not the same as doing nothing because ignoring a signal requires the program to have some code that explicitly ignores the signal.

  • Catch the signal and perform some signal-specific commands. This method requires the program to define a function that is executed when a signal is received. This is the most complex and powerful method of dealing with a signal.

The first method is the default behavior for all shell scripts. All the scripts that you have looked at thus far handle signals ...

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