gawk: Exit Status

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1 2.6 'gawk''s Exit Status
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1 If the 'exit' statement is used with a value (⇒Exit Statement),
1 then 'gawk' exits with the numeric value given to it.
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1    Otherwise, if there were no problems during execution, 'gawk' exits
1 with the value of the C constant 'EXIT_SUCCESS'.  This is usually zero.
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1    If an error occurs, 'gawk' exits with the value of the C constant
1 'EXIT_FAILURE'.  This is usually one.
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1    If 'gawk' exits because of a fatal error, the exit status is two.  On
1 non-POSIX systems, this value may be mapped to 'EXIT_FAILURE'.
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