PostgreSQL C language function

C language functions require more work than functions written in other languages. As with all C programs, they must first be compiled. The 

Suppose this code exists in a file bits.c. The following linux commands will process this file and make it useable as a new PostgreSQL function. 

The directories named in these commands are valid for version 8.2 of PostgreSQL running on a Ubuntu linux machine. They may be valid for other distributions of linux, but may need to be adjusted for another installation. 

Returns integer AS bits, ribits set Language c Immutable Strict Comment On Function nbits set(bit) Is number of bits set  

In functions written in other languages, the code appears in the create command, whether it is written in SQL, plpgsql, plperl, or plpython. For C language functions, the name of the shared object, here bits.so, and the name of the c function, here nbits set are named in the create command. 

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