The c99 utility is an interface to the standard C compilation
system; it shall accept source code conforming to the ISO C
standard. The system conceptually consists of a compiler and link
editor. The input files referenced by pathname operands and -l
option-arguments shall be compiled and linked to produce an
executable file. (It is unspecified whether the linking occurs
entirely within the operation of c99; some implementations may
produce objects that are not fully resolved until the file is
executed.)
If the -c option is specified, for all pathname operands of the
form file.c, the files:
$(basename pathname .c).o
shall be created as the result of successful compilation. If the
-c option is not specified, it is unspecified whether such .o
files are created or deleted for the file.c operands.
If there are no options that prevent link editing (such as -c or
-E), and all input files compile and link without error, the
resulting executable file shall be written according to the -o
outfile option (if present) or to the file a.out.
The executable file shall be created as specified in Section
1.1.1.4, File Read, Write, and Creation, except that the file
permission bits shall be set to: S_IRWXO | S_IRWXG | S_IRWXU
and the bits specified by the umask of the process shall be
cleared.
