NAME
c99 - compile standard C programs
SYNOPSIS
c99 [-c] [-Dname[=tokens]] [-E] [-g] [-Idirectory]
[-Ldirectory] [-Ooptlevel] [-ooutfile] [-s] [-Uname]
DESCRIPTION
This release of the c99 utility is compliant with the
Standard for Information Technology - Portable Operating
System Interface (POSIX(R))
Shell and Utilities, Issue 6 (Volume 1: A to J) Apporved 12
September 2001.
The c99 utility is an interface to the standard C compila-
tion system; it will accept source code conforming to the
ISO C standard. The system conceptually consists of a com-
piler and link editor. The files referenced by operands
will be compiled and linked to produce an executable file.
If the -c option is specified, for all pathname operands of
the form file.c,the files:
$(basename pathname .c).o
will be created as the result of successful compilation.
If there are no options that prevent link editing (such as
-c or -E), and all operands compile and link without error,
the resulting executable file will be written according to
the -o outfile option (if present) or to the file a.out.
The file permissions for the executable file that is created
are set to
S_IRWXO | S_IRWXG | S_IRWXU
and the bits specified by the umask of the process are
cleared.
OPTIONS
The following affect the options for the c99 utility:
o The -l library operands have the format of options,
but their position within a list of operands affects
the order in which libraries are searched.
o The order of specifying the -I and -L options is
significant.
o Portable applications must specify each option
separately; that is, grouping option letters (for
example, -cO) need not be recognized by all imple-
mentations.
The following options are supported:
-c Suppress the link-edit phase of the compila-
tion, and do not remove any object files that
are produced.
-D name[=value]
Define name as if by a C-language #define
directive. If no =value is given, a value of
1 will be used. The -D option has lower pre-
cedence 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. c99 supports at least 2048
bytes of -D definitions and 256 names.
The following predefined names are valid in
all modes:
__sparc (SPARC)
__i386 (x86)
__unix
__sun
__BUILTIN_VA_ARG_INCR
__SUNPRO_C=0x570
__SVR4
The following names are not predefined:
unix
sparc (SPARC)
i386 (x86)
sun
-E Copy C-language source files to standard out-
put, expanding all preprocessor directives;
no compilation will be performed. An error
will occur if any operand is not a text file.
-g Produce symbolic information in the object or
executable files.
-I directory Change the algorithm for searching for
headers whose names are not absolute path-
names to look in the directory named by the
directory path name 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 direc-
tories 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 will
be searched in the order specified.
-L directory Change the algorithm of searching for the
libraries named in the -l objects to look in
the directory named by the directory path
name before looking in the usual places.
Directories named in -L options will be
searched in the order specified.
-O optlevel Specify the level of code optimization. If
the optlevel option-argument is the digit 0,
all special code optimizations are disabled.
See the cc(1) manpage for a description of
the optimization levels.
-o outfile Use the pathname outfile, instead of the
default a.out, for the executable file pro-
duced. This option cannot be used with -c or
-E.
-s Produce object or executable files, or both,
from which symbolic and other information not
required for proper execution using the exec
family has been removed (stripped). If both
-g and -s options are present, -s overrides
-g.
-U name Remove any initial definition of name.
Multiple instances of the -D, -I, -U, and -L options can be
specified.
OPERANDS
An operand is either in the form of a path name or the form
-l library. At least one operand of the path name form must
be specified. The following operands are supported:
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 typically produced
by the ar(1) utility, and passed directly to
the link editor.
file.o An object file produced by c99 -c and passed
directly to the link editor.
-l library (The letter ell.) 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. Several standard libraries
can be specified in this manner. See Stan-
dard Libraries in NOTES below.
USAGE
Since the c99 utility usually creates files in the current
directory during the compilation process, it is typically
necessary to run the c99 utility in a directory in which a
file can be created.
c99 creates .o files when -c is not specified and more than
one source file is given.
Some historical implementations have permitted -L options to
be interspersed with -l operands on the command line. For
an application to compile consistently on systems that do
not behave like this, it is necessary for a portable appli-
cation to supply all -L options before any of the -l
options.
There is the possible implication that if a user supplies
versions of the standard library functions (before they
would be encountered by an implicit -l c or explicit -l m),
that those versions would be used in place of the standard
versions. There are various reasons this might not be true
(functions defined as macros, manipulations for clean name
space, and so forth), so the existence of files named in the
same manner as the standard libraries within the -L direc-
tories is explicitly stated to produce unspecified behavior.
Setting the environment variable TMPDIR overrides the
default temporary directory.
OUTPUT
STDOUT
If more than one file operand ending in .c is given, for
each such file:
"%s:\n", <file>
may be written. These messages, if written, will precede
the processing of each input file; they will not be written
to the standard output if they are written to the standard
error, as described in STDERR.
If the -E option is specified, the standard output will be a
text file that represents the results of the preprocessing
stage of the language; it may contain extra information
appropriate for subsequent compilation passes.
STDERR
Used only for diagnostic messages. If more than one file
operand ending in .c (or possibly other unspecified suf-
fixes) is given, for each such file:
"%s:\n", <file>
may be written to allow identification of the diagnostic and
warning messages with the appropriate input file. These
messages, if written, will precede the processing of each
input file; they will not be written to the standard error
if they are written to the standard output, as described in
STDOUT.
ENVIRONMENT
See environ(5) for descriptions of the following environment
variables that affect the execution of c99: LANG, LC_ALL,
LC_TYPE, LC_MESSAGES, and NLSPATH.
TMPDIR Provide a path name that will override the
default directory for temporary files, if
any.
EXIT STATUS
The following exit values are returned:
0 Successful compilation or link edit.
>0 An error occurred.
When c99 encounters a compilation error that causes an
object file not to be created, it will write a diagnostic to
standard error and continue to compile other source code
operands, but it will not perform the link phase and will
return a non-zero exit status. If the link edit is unsuc-
cessful, a diagnostic message will be written to standard
error and c99 will exit with a non-zero status. A portable
application must rely on the exit status of c99, rather than
on the existence or mode of the executable file.
EXAMPLES
The following are examples of usage:
c99 -o foo foo.c Compiles foo.c and creates the exe-
cutable file foo.
c99 -c foo.c Compiles foo.c and creates the
object file foo.o.
c99 foo.c Compiles foo.c and creates the exe-
cutable file a.out.
c99 foo.c bar.o Compiles foo.c, links it with bar.o,
and creates the executable file
a.out. Also creates and leaves
foo.o.
The following examples clarify the use and interactions of
-L options and -l operands: Consider the case in which
module a.c calls function f in library libQ.a, and module
b.c calls function g in library libp.a. Assume that both
libraries reside in /a/b/c. The command line to compile and
link in the desired way is:
c99 -L /a/b/c main.o a.c -l Q b.c -l p
In this case the -l Q operand need only precede the first -l
p operand, since both libQ.a and libp.a reside in the same
directory.
Multiple -L operands can be used when library name colli-
sions occur. Building on the previous example, suppose that
the user wants to use a new libp.a, in /a/a/a, but still
wants f from /a/b/c/libQ.a:
c99 -L /a/a/a -L /a/b/c main.o a.c -l Q b.c -l p
In this example, the linker searches the -L options in the
order specified, and finds /a/a/a/libp.a before
/a/b/c/libp.a when resolving references for b.c. The order
of the -l operands is still important, however.
SEE ALSO
ar(1), cc(1B), nm(1), strip(1), umask(1), environ(5)
NOTES
Standard Libraries
The c99 utility recognizes the following -l operands for
standard libraries:
-l c This library contains all library functions
except for those functions listed as residing in
<math.h>. This operand is not required to be
present to cause a search of this library.
-l m This library contains all functions referenced
in math.h. An implementation may search this
library in the absence of this operand.
-l l This library contains all functions required by
the C-language output of lex that are not made
available through the -l c operand.
-l pthread This operand makes visible all functions refer-
enced in <pthread.h>and pthread_atfork() refer-
enced in <unistd.h>. An implementation may
search this library in the absence of this
operand.
-l rt This operand makes visible all functions refer-
enced in <aio.h>, <mqueue.h>, <sched.h>, and
<time.h>. An implementation may search this
library in the absence of this operand.
-l y This library contains all functions required by
the C-language output of yacc that are not made
available through the -l c operand.
In the absence of options that inhibit invocation of the
link editor, such as -c or -E, the c99 utility will cause
the equivalent of a -l c operand to be passed to the link
editor as the last -l operand, causing it to be searched
after all other object files and libraries are loaded.
External Symbols
The C compiler and link editor support the significance of
external symbols up to a length of at least 31 bytes.
The compiler and link editor support a minimum of 511 exter-
nal symbols per source or object file, and a minimum of 4095
external symbols in total. A diagnostic message will be
written to the standard output if the limit is exceeded.