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ex.: macro to free+nullify an object

how to put a block of code in CPP
#define BLOCK	S1;S2;S3
w/ or w/o terminating ';'?
	odd/ugly if you don't have to put terminating ';'
	indentation problems with emacs and /bin/indent
problem: if (c) BLOCK

#define BLOCK	{S1;S2;S3;}
problem: if (c) BLOCK

#define BLOCK do {S1;S2;S3;} while (0)
works everywhere

inline functions

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* HW3

shell scripts to test for features
- collecting info in config.h
- testing headers
- testing functions
- testing C features
- testing CPP features
- temp files

* Testing features

testing features, eg getitimer() and time headers
wrapper shell script:
        if [ -f /usr/include/...]; then
                gcc -DFOO_BAR
        fi
how can you find out if you can include both
        time.h and sys/time.h
what about systems that have neither?