Advanced Programming in the UNIX® Environment

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24 UNIX System Overview Chapter 1


The next chapter is about standardization of the UNIX System and the effect of
work in this area on current systems. Standards, particularly the ISO C standardand
the POSIX.1 standard, will affect the rest of the text.

Exercises


1.1 Verify on your system that the directories dot and dot-dot arenot the same, except in the
root directory.
1.2 In the output from the program in Figure1.6, what happened to the processes with process
IDs 852 and 853?
1.3 In Section 1.7, the argument toperroris defined with the ISO C attributeconst,whereas
the integer argument tostrerrorisn’t defined with this attribute. Why?
1.4 If the calendar time is stored as a signed 32-bit integer, in which year will it overflow? How
can we extend the overflow point? Arethese strategies compatible with existing
applications?
1.5 If the process time is stored as a signed 32-bit integer,and if the system counts 100 ticks per
second, after how many days will the value overflow?
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