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PROLOG | NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | STDIN | INPUT FILES | ENVIRONMENT VARIABLES | ASYNCHRONOUS EVENTS | STDOUT | STDERR | OUTPUT FILES | EXTENDED DESCRIPTION | EXIT STATUS | CONSEQUENCES OF ERRORS | APPLICATION USAGE | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
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C99(1P) POSIX Programmer's Manual C99(1P)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
c99 — compile standard C programs
c99 [options...] pathname [[pathname] [-I directory]
[-L directory] [-l library]]...
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.
The c99 utility shall conform to the Base Definitions volume of
POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines, except
that:
* Options can be interspersed with operands.
* The order of specifying the -L and -l options, and the order
of specifying -l options with respect to pathname operands is
significant.
* Conforming applications shall specify each option separately;
that is, grouping option letters (for example, -cO) need not
be recognized by all implementations.
The following options shall be supported:
-c Suppress the link-edit phase of the compilation, 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 shall be used. 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
shall be undefined regardless of the order of the
options. Additional implementation-defined names may be
provided by the compiler. Implementations shall support
at least 2048 bytes of -D definitions and 256 names.
-E Copy C-language source files to standard output,
executing all preprocessor directives; no compilation
shall be performed. If any operand is not a text file,
the effects are unspecified.
-g Produce symbolic information in the object or
executable files; the nature of this information is
unspecified, and may be modified by implementation-
defined interactions with other options.
-I directory
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 ("") shall 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 shall
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. If
the -I option is used to specify a directory that is
one of the usual places searched by default, the
results are unspecified. Implementations shall support
at least ten instances of this option in a single c99
command invocation.
-L directory
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 shall be
searched in the order specified. If the -L option is
used to specify a directory that is one of the usual
places searched by default, the results are
unspecified. Implementations shall support at least ten
instances of this option in a single c99 command
invocation. If a directory specified by a -L option
contains files with names starting with any of the
strings "libc.", "libl.", "libpthread.", "libm.",
"librt.", "libtrace.", "libxnet.", or "liby.", the
results are unspecified.
-l library
Search the library named liblibrary.a. A library shall
be searched when its name is encountered, so the
placement of a -l option is significant. Several
standard libraries can be specified in this manner, as
described in the EXTENDED DESCRIPTION section.
Implementations may recognize implementation-defined
suffixes other than .a as denoting libraries.
-O optlevel
Specify the level of code optimization. If the optlevel
option-argument is the digit '0', all special code
optimizations shall be disabled. If it is the digit
'1', the nature of the optimization is unspecified. If
the -O option is omitted, the nature of the system's
default optimization is unspecified. It is unspecified
whether code generated in the presence of the -O 0
option is the same as that generated when -O is
omitted. Other optlevel values may be supported.
-o outfile
Use the pathname outfile, instead of the default a.out,
for the executable file produced. If the -o option is
present with -c or -E, the result is unspecified.
-s Produce object or executable files, or both, from which
symbolic and other information not required for proper
execution using the exec family defined in the System
Interfaces volume of POSIX.1‐2017 has been removed
(stripped). If both -g and -s options are present, the
action taken is unspecified.
-U name Remove any initial definition of name.
Multiple instances of the -D, -I, -L, -l, and -U options can be
specified.
The application shall ensure that at least one pathname operand
is specified. The following forms for pathname operands shall be
supported:
file.c A C-language source file to be compiled and optionally
linked. The application shall ensure that the operand
is of this form if the -c option is used.
file.a A library of object files typically produced by the ar
utility, and passed directly to the link editor.
Implementations may recognize implementation-defined
suffixes other than .a as denoting object file
libraries.
file.o An object file produced by c99 -c and passed directly
to the link editor. Implementations may recognize
implementation-defined suffixes other than .o as
denoting object files.
The processing of other files is implementation-defined.
Not used.
Each input file shall be one of the following: a text file
containing a C-language source program, an object file in the
format produced by c99 -c, or a library of object files, in the
format produced by archiving zero or more object files, using ar.
Implementations may supply additional utilities that produce
files in these formats. Additional input file formats are
implementation-defined.
The following environment variables shall affect the execution of
c99:
LANG Provide a default value for the internationalization
variables that are unset or null. (See the Base
Definitions volume of POSIX.1‐2017, Section 8.2,
Internationalization Variables for the precedence of
internationalization variables used to determine the
values of locale categories.)
LC_ALL If set to a non-empty string value, override the values
of all the other internationalization variables.
LC_CTYPE Determine the locale for the interpretation of
sequences of bytes of text data as characters (for
example, single-byte as opposed to multi-byte
characters in arguments and input files).
LC_MESSAGES
Determine the locale that should be used to affect the
format and contents of diagnostic messages written to
standard error.
NLSPATH Determine the location of message catalogs for the
processing of LC_MESSAGES.
TMPDIR Provide a pathname that should override the default
directory for temporary files, if any. On XSI-
conforming systems, provide a pathname that shall
override the default directory for temporary files, if
any.
Default.
If more than one pathname operand ending in .c (or possibly other
unspecified suffixes) is given, for each such file:
"%s:\n", <pathname>
may be written. These messages, if written, shall precede the
processing of each input file; they shall not be written to the
standard output if they are written to the standard error, as
described in the STDERR section.
If the -E option is specified, the standard output shall 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.
The standard error shall be used only for diagnostic messages.
If more than one pathname operand ending in .c (or possibly other
unspecified suffixes) is given, for each such file:
"%s:\n", <pathname>
may be written to allow identification of the diagnostic and
warning messages with the appropriate input file. These messages,
if written, shall precede the processing of each input file; they
shall not be written to the standard error if they are written to
the standard output, as described in the STDOUT section.
This utility may produce warning messages about certain
conditions that do not warrant returning an error (non-zero) exit
value.
Object files or executable files or both are produced in
unspecified formats. If the pathname of an object file or
executable file to be created by c99 resolves to an existing
directory entry for a file that is not a regular file, it is
unspecified whether c99 shall attempt to create the file or shall
issue a diagnostic and exit with a non-zero exit status.
Standard Libraries
The c99 utility shall recognize the following -l options for
standard libraries:
-l c This option shall make available all interfaces
referenced in the System Interfaces volume of
POSIX.1‐2017, with the possible exception of those
interfaces listed as residing in <aio.h>,
<arpa/inet.h>, <complex.h>, <fenv.h>, <math.h>,
<mqueue.h>, <netdb.h>, <net/if.h>, <netinet/in.h>,
<pthread.h>, <sched.h>, <semaphore.h>, <spawn.h>,
<sys/socket.h>, pthread_kill(), and pthread_sigmask()
in <signal.h>, <trace.h>, interfaces marked as optional
in <sys/mman.h>, interfaces marked as ADV (Advisory
Information) in <fcntl.h>, and interfaces beginning
with the prefix clock_ or timer_ in <time.h>. This
option shall not be required to be present to cause a
search of this library.
-l l This option shall make available all interfaces
required by the C-language output of lex that are not
made available through the -l c option.
-l pthread
This option shall make available all interfaces
referenced in <pthread.h> and pthread_kill() and
pthread_sigmask() referenced in <signal.h>. An
implementation may search this library in the absence
of this option.
-l m This option shall make available all interfaces
referenced in <math.h>, <complex.h>, and <fenv.h>. An
implementation may search this library in the absence
of this option.
-l rt This option shall make available all interfaces
referenced in <aio.h>, <mqueue.h>, <sched.h>,
<semaphore.h>, and <spawn.h>, interfaces marked as
optional in <sys/mman.h>, interfaces marked as ADV
(Advisory Information) in <fcntl.h>, and interfaces
beginning with the prefix clock_ and timer_ in
<time.h>. An implementation may search this library in
the absence of this option.
-l trace This option shall make available all interfaces
referenced in <trace.h>. An implementation may search
this library in the absence of this option.
-l xnet This option shall make available all interfaces
referenced in <arpa/inet.h>, <netdb.h>, <net/if.h>,
<netinet/in.h>, and <sys/socket.h>. An implementation
may search this library in the absence of this option.
-l y This option shall make available all interfaces
required by the C-language output of yacc that are not
made available through the -l c option.
In the absence of options that inhibit invocation of the link
editor, such as -c or -E, the c99 utility shall cause the
equivalent of a -l c option to be passed to the link editor after
the last pathname operand or -l option, causing it to be searched
after all other object files and libraries are loaded.
It is unspecified whether the libraries libc.a, libl.a, libm.a,
libpthread.a, librt.a, libtrace.a, libxnet.a, or liby.a exist as
regular files. The implementation may accept as -l option-
arguments names of objects that do not exist as regular files.
External Symbols
The C compiler and link editor shall support the significance of
external symbols up to a length of at least 31 bytes; the action
taken upon encountering symbols exceeding the implementation-
defined maximum symbol length is unspecified.
The compiler and link editor shall support a minimum of 511
external symbols per source or object file, and a minimum of 4095
external symbols in total. A diagnostic message shall be written
to the standard output if the implementation-defined limit is
exceeded; other actions are unspecified.
Header Search
If a file with the same name as one of the standard headers
defined in the Base Definitions volume of POSIX.1‐2017, Chapter
13, Headers, not provided as part of the implementation, is
placed in any of the usual places that are searched by default
for headers, the results are unspecified.
Programming Environments
All implementations shall support one of the following
programming environments as a default. Implementations may
support more than one of the following programming environments.
Applications can use sysconf() or getconf to determine which
programming environments are supported.
Table 4-4: Programming Environments: Type Sizes
┌─────────────────────────┬─────────┬─────────┬─────────┬─────────┐
│ Programming Environment │ Bits in │ Bits in │ Bits in │ Bits in │
│ getconf Name │ int │ long │ pointer │ off_t │
├─────────────────────────┼─────────┼─────────┼─────────┼─────────┤
│ _POSIX_V7_ILP32_OFF32 │ 32 │ 32 │ 32 │ 32 │
│ _POSIX_V7_ILP32_OFFBIG │ 32 │ 32 │ 32 │ ≥64 │
│ _POSIX_V7_LP64_OFF64 │ 32 │ 64 │ 64 │ 64 │
│ _POSIX_V7_LPBIG_OFFBIG │ ≥32 │ ≥64 │ ≥64 │ ≥64 │
└─────────────────────────┴─────────┴─────────┴─────────┴─────────┘
All implementations shall support one or more environments where
the widths of the following types are no greater than the width
of type long:
blksize_t ptrdiff_t tcflag_t
cc_t size_t wchar_t
mode_t speed_t wint_t
nfds_t ssize_t
pid_t suseconds_t
The executable files created when these environments are selected
shall be in a proper format for execution by the exec family of
functions. Each environment may be one of the ones in Table 4-4,
Programming Environments: Type Sizes, or it may be another
environment. The names for the environments that meet this
requirement shall be output by a getconf command using the
POSIX_V7_WIDTH_RESTRICTED_ENVS argument, as a <newline>-separated
list of names suitable for use with the getconf -v option. If
more than one environment meets the requirement, the names of all
such environments shall be output on separate lines. Any of these
names can then be used in a subsequent getconf command to obtain
the flags specific to that environment with the following
suffixes added as appropriate:
_CFLAGS To get the C compiler flags.
_LDFLAGS To get the linker/loader flags.
_LIBS To get the libraries.
This requirement may be removed in a future version.
When this utility processes a file containing a function called
main(), it shall be defined with a return type equivalent to int.
Using return from the initial call to main() shall be equivalent
(other than with respect to language scope issues) to calling
exit() with the returned value. Reaching the end of the initial
call to main() shall be equivalent to calling exit(0). The
implementation shall not declare a prototype for this function.
Implementations provide configuration strings for C compiler
flags, linker/loader flags, and libraries for each supported
environment. When an application needs to use a specific
programming environment rather than the implementation default
programming environment while compiling, the application shall
first verify that the implementation supports the desired
environment. If the desired programming environment is supported,
the application shall then invoke c99 with the appropriate C
compiler flags as the first options for the compile, the
appropriate linker/loader flags after any other options except -l
but before any operands or -l options, and the appropriate
libraries at the end of the operands and -l options.
Conforming applications shall not attempt to link together object
files compiled for different programming models. Applications
shall also be aware that binary data placed in shared memory or
in files might not be recognized by applications built for other
programming models.
Table 4-5: Programming Environments: c99 Arguments
┌─────────────────────────┬─────────────────────┬───────────────────────────────┐
│ Programming Environment │ │ c99 Arguments │
│ getconf Name │ Use │ getconf Name │
├─────────────────────────┼─────────────────────┼───────────────────────────────┤
│ _POSIX_V7_ILP32_OFF32 │ C Compiler Flags │ POSIX_V7_ILP32_OFF32_CFLAGS │
│ │ Linker/Loader Flags │ POSIX_V7_ILP32_OFF32_LDFLAGS │
│ │ Libraries │ POSIX_V7_ILP32_OFF32_LIBS │
├─────────────────────────┼─────────────────────┼───────────────────────────────┤
│ _POSIX_V7_ILP32_OFFBIG │ C Compiler Flags │ POSIX_V7_ILP32_OFFBIG_CFLAGS │
│ │ Linker/Loader Flags │ POSIX_V7_ILP32_OFFBIG_LDFLAGS │
│ │ Libraries │ POSIX_V7_ILP32_OFFBIG_LIBS │
├─────────────────────────┼─────────────────────┼───────────────────────────────┤
│ _POSIX_V7_LP64_OFF64 │ C Compiler Flags │ POSIX_V7_LP64_OFF64_CFLAGS │
│ │ Linker/Loader Flags │ POSIX_V7_LP64_OFF64_LDFLAGS │
│ │ Libraries │ POSIX_V7_LP64_OFF64_LIBS │
├─────────────────────────┼─────────────────────┼───────────────────────────────┤
│ _POSIX_V7_LPBIG_OFFBIG │ C Compiler Flags │ POSIX_V7_LPBIG_OFFBIG_CFLAGS │
│ │ Linker/Loader Flags │ POSIX_V7_LPBIG_OFFBIG_LDFLAGS │
│ │ Libraries │ POSIX_V7_LPBIG_OFFBIG_LIBS │
└─────────────────────────┴─────────────────────┴───────────────────────────────┘
In addition to the type size programming environments above, all
implementations also support a multi-threaded programming
environment that is orthogonal to all of the programming
environments listed above. The getconf utility can be used to
get flags for the threaded programming environment, as indicated
in Table 4-6, Threaded Programming Environment: c99 Arguments.
Table 4-6: Threaded Programming Environment: c99 Arguments
┌─────────────────────────┬─────────────────────┬──────────────────────────┐
│ Programming Environment │ │ c99 Arguments │
│ getconf Name │ Use │ getconf Name │
├─────────────────────────┼─────────────────────┼──────────────────────────┤
│ _POSIX_THREADS │ C Compiler Flags │ POSIX_V7_THREADS_CFLAGS │
│ │ Linker/Loader Flags │ POSIX_V7_THREADS_LDFLAGS │
└─────────────────────────┴─────────────────────┴──────────────────────────┘
These programming environment flags may be used in conjunction
with any of the type size programming environments supported by
the implementation.
The following exit values shall be 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 shall write a diagnostic to standard
error and continue to compile other source code operands, but it
shall not perform the link phase and it shall return a non-zero
exit status. If the link edit is unsuccessful, a diagnostic
message shall be written to standard error and c99 exits with a
non-zero status. A conforming application shall rely on the exit
status of c99, rather than on the existence or mode of the
executable file.
The following sections are informative.
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.
On systems providing POSIX Conformance (see the Base Definitions
volume of POSIX.1‐2017, Chapter 2, Conformance), c99 is required
only with the C-Language Development option; XSI-conformant
systems always provide c99.
Some historical implementations have created .o files when -c is
not specified and more than one source file is given. Since this
area is left unspecified, the application cannot rely on .o files
being created, but it also must be prepared for any related .o
files that already exist being deleted at the completion of the
link edit.
There is the possible implication that if a user supplies
versions of the standard 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 on), so the
existence of files named in the same manner as the standard
libraries within the -L directories is explicitly stated to
produce unspecified behavior.
All of the functions specified in the System Interfaces volume of
POSIX.1‐2017 may be made visible by implementations when the
Standard C Library is searched. Conforming applications must
explicitly request searching the other standard libraries when
functions made visible by those libraries are used.
In the ISO C standard the mapping from physical source characters
to the C source character set is implementation-defined.
Implementations may strip white-space characters before the
terminating <newline> of a (physical) line as part of this
mapping and, as a consequence of this, one or more white-space
characters (and no other characters) between a <backslash>
character and the <newline> character that terminates the line
produces implementation-defined results. Portable applications
should not use such constructs.
Some c99 compilers not conforming to POSIX.1‐2008 do not support
trigraphs by default.
1. The following usage example compiles foo.c and creates the
executable file foo:
c99 -o foo foo.c
The following usage example compiles foo.c and creates the
object file foo.o:
c99 -c foo.c
The following usage example compiles foo.c and creates the
executable file a.out:
c99 foo.c
The following usage example compiles foo.c, links it with
bar.o, and creates the executable file a.out. It may also
create and leave foo.o:
c99 foo.c bar.o
2. The following example shows how an application using threads
interfaces can test for support of and use a programming
environment supporting 32-bit int, long, and pointer types
and an off_t type using at least 64 bits:
offbig_env=$(getconf _POSIX_V7_ILP32_OFFBIG)
if [ $offbig_env != "-1" ] && [ $offbig_env != "undefined" ]
then
c99 $(getconf POSIX_V7_ILP32_OFFBIG_CFLAGS) \
$(getconf POSIX_V7_THREADS_CFLAGS) -D_XOPEN_SOURCE=700 \
$(getconf POSIX_V7_ILP32_OFFBIG_LDFLAGS) \
$(getconf POSIX_V7_THREADS_LDFLAGS) foo.c -o foo \
$(getconf POSIX_V7_ILP32_OFFBIG_LIBS) \
-l pthread
else
echo ILP32_OFFBIG programming environment not supported
exit 1
fi
3. The following examples clarify the use and interactions of -L
and -l options.
Consider the case in which module a.c calls function f() in
library libQ.a, and module b.c calls function g() in library
libp.a. Assume that both libraries reside in /a/b/c. The
command line to compile and link in the desired way is:
c99 -L /a/b/c main.o a.c -l Q b.c -l p
In this case the -L option need only precede the first -l
option, since both libQ.a and libp.a reside in the same
directory.
Multiple -L options can be used when library name collisions
occur. Building on the previous example, suppose that the
user wants to use a new libp.a, in /a/a/a, but still wants
f() from /a/b/c/libQ.a:
c99 -L /a/a/a -L /a/b/c main.o a.c -l Q b.c -l p
In this example, the linker searches the -L options in the
order specified, and finds /a/a/a/libp.a before /a/b/c/libp.a
when resolving references for b.c. The order of the -l
options is still important, however.
4. The following example shows how an application can use a
programming environment where the widths of the following
types: blksize_t, cc_t, mode_t, nfds_t, pid_t, ptrdiff_t,
size_t, speed_t, ssize_t, suseconds_t, tcflag_t, wchar_t,
wint_t
are no greater than the width of type long:
# First choose one of the listed environments ...
# ... if there are no additional constraints, the first one will do:
CENV=$(getconf POSIX_V7_WIDTH_RESTRICTED_ENVS | head -n l)
# ... or, if an environment that supports large files is preferred,
# look for names that contain "OFF64" or "OFFBIG". (This chooses
# the last one in the list if none match.)
for CENV in $(getconf POSIX_V7_WIDTH_RESTRICTED_ENVS)
do
case $CENV in
*OFF64*|*OFFBIG*) break ;;
esac
done
# The chosen environment name can now be used like this:
c99 $(getconf ${CENV}_CFLAGS) -D _POSIX_C_SOURCE=200809L \
$(getconf ${CENV}_LDFLAGS) foo.c -o foo \
$(getconf ${CENV}_LIBS)
The c99 utility is based on the c89 utility originally introduced
in the ISO POSIX‐2:1993 standard.
Some of the changes from c89 include the ability to intersperse
options and operands (which many c89 implementations allowed
despite it not being specified), the description of -l as an
option instead of an operand, and the modification to the
contents of the Standard Libraries section to account for new
headers and options; for example, <spawn.h> added to the
description of -l rt, and -l trace added for the Tracing option.
POSIX.1‐2008 specifies that the c99 utility must be able to use
regular files for *.o files and for a.out files. Implementations
are free to overwrite existing files of other types when
attempting to create object files and executable files, but are
not required to do so. If something other than a regular file is
specified and using it fails for any reason, c99 is required to
issue a diagnostic message and exit with a non-zero exit status.
But for some file types, the problem may not be noticed for a
long time. For example, if a FIFO named a.out exists in the
current directory, c99 may attempt to open a.out and will hang in
the open() call until another process opens the FIFO for reading.
Then c99 may write most of the a.out to the FIFO and fail when it
tries to seek back close to the start of the file to insert a
timestamp (FIFOs are not seekable files). The c99 utility is also
allowed to issue a diagnostic immediately if it encounters an
a.out or *.o file that is not a regular file. For portable use,
applications should ensure that any a.out, -o option-argument, or
*.o files corresponding to any *.c files do not conflict with
names already in use that are not regular files or symbolic links
that point to regular files.
On many systems, multi-threaded applications run in a programming
environment that is distinct from that used by single-threaded
applications. This multi-threaded programming environment (in
addition to needing to specify -l pthread at link time) may
require additional flags to be set when headers are processed at
compile time (-D_REENTRANT being common). This programming
environment is orthogonal to the type size programming
environments discussed above and listed in Table 4-4, Programming
Environments: Type Sizes. This version of the standard adds
getconf utility calls to provide the C compiler flags and
linker/loader flags needed to support multi-threaded
applications. Note that on a system where single-threaded
applications are a special case of a multi-threaded application,
both of these getconf calls may return NULL strings; on other
implementations both of these strings may be non-NULL strings.
The C standardization committee invented trigraphs (e.g., "??!"
to represent '|') to address character portability problems in
development environments based on national variants of the 7-bit
ISO/IEC 646:1991 standard character set. However, these
environments were already obsolete by the time the first ISO C
standard was published, and in practice trigraphs have not been
used for their intended purpose, and usually are intended to have
their original meaning in K&R C. For example, in practice a C-
language source string like "What??!" is usually intended to end
in two <question-mark> characters and an <exclamation-mark>, not
in '|'.
When the -E option is used, execution of some #pragma
preprocessor directives may simply result in a copy of the
directive being included in the output as part of the allowed
extra information used by subsequent compilation passes (see
STDOUT).
Unlike all of the other non-OB-shaded utilities in this standard,
a utility by this name probably will not appear in the next
version of this standard. This utility's name is tied to the
current revision of the ISO C standard at the time this standard
is approved. Since the ISO C standard and this standard are
maintained by different organizations on different schedules, we
cannot predict what the compiler will be named in the next
version of the standard.
Section 1.1.1.4, File Read, Write, and Creation, ar(1p),
getconf(1p), make(1p), nm(1p), strip(1p), umask(1p)
The Base Definitions volume of POSIX.1‐2017, Chapter 8,
Environment Variables, Section 12.2, Utility Syntax Guidelines,
Chapter 13, Headers
The System Interfaces volume of POSIX.1‐2017, exec(1p),
sysconf(3p)
Portions of this text are reprinted and reproduced in electronic
form from IEEE Std 1003.1-2017, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The
Open Group Base Specifications Issue 7, 2018 Edition, Copyright
(C) 2018 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any
discrepancy between this version and the original IEEE and The
Open Group Standard, the original IEEE and The Open Group
Standard is the referee document. The original Standard can be
obtained online at http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear in this page
are most likely to have been introduced during the conversion of
the source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2017 C99(1P)
Pages that refer to this page: ar(1p), cflow(1p), ctags(1p), cxref(1p), fort77(1p), getconf(1p), lex(1p), m4(1p), make(1p), nm(1p), od(1p), strip(1p), yacc(1p), confstr(3p)
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