C99(1) General Commands Manual C99(1)
c99 – standard C language compiler
c99 [-cEgs] [-D name[=value]] ... [-I directory ...] [-L directory ...]
[-o outfile] [-O optlevel] [-U name ...] [-W 32|64] operand ...
This is the name of the C language compiler as required by the IEEE Std
1003.1-2001 (“POSIX.1”) standard.
The c99 compiler accepts the following options:
-c Suppress the link-edit phase of the compilation, and do not remove
any object files that are produced.
Define name as if by a C-language #define directive. If no
“=value” is given, a value of 1 will be used. Note that in order
to request a translation as specified by IEEE Std 1003.1-2001
(“POSIX.1”), you need to define _POSIX_C_SOURCE=200112L either in
the source or using this option. The -D option has lower
precedence than the -U option. That is, if name is used in both a
-U and a -D option, name will be undefined regardless of the order
of the options. The -D option may be specified more than once.
-E Copy C-language source files to the standard output, expanding all
preprocessor directives; no compilation will be performed.
-g Produce symbolic information in the object or executable files.
Change the algorithm for searching for headers whose names are not
absolute pathnames to look in the directory named by the directory
pathname before looking in the usual places. Thus, headers whose
names are enclosed in double-quotes ("") will be searched for first
in the directory of the file with the #include line, then in
directories named in -I options, and last in the usual places. For
headers whose names are enclosed in angle brackets (⟨⟩), the header
will be searched for only in directories named in -I options and
then in the usual places. Directories named in -I options shall be
searched in the order specified. The -I option may be specified
more than once.
Change the algorithm of searching for the libraries named in the -l
objects to look in the directory named by the directory pathname
before looking in the usual places. Directories named in -L
options will be searched in the order specified. The -L option may
be specified more than once.
Use the pathname outfile, instead of the default a.out, for the
executable file produced.
If optlevel is zero, disable all optimizations. Otherwise, enable
optimizations at the specified level.
-s Produce object and/or executable files from which symbolic and
other information not required for proper execution has been
Remove any initial definition of name. The -U option may be
specified more than once.
Set the pointer size for the compiled code to either 32 or 64 bits.
If not specified, the pointer size matches the current host
An operand is either in the form of a pathname or the form -l library. At
least one operand of the pathname form needs to be specified. Supported
operands are of the form:
file.c A C-language source file to be compiled and
optionally linked. The operand must be of this
form if the -c option is used.
file.a A library of object files, as produced by ar(1),
passed directly to the link editor.
file.o An object file produced by c99 -c, and passed
directly to the link editor.
-l library Search the library named liblibrary.a. A library
will be searched when its name is encountered, so
the placement of a -l operand is significant.
ar(1), c89(1), cc(1)
The c99 utility interface conforms to IEEE Std 1003.1-2001 (“POSIX.1”).
macOS 12.1 October 7, 2002 macOS 12.1