unistd.h.html

IEEE 1003.1-2003, Single Unix Specification v3

<p>The following symbolic constants shall be defined for <a href="../functions/sysconf.html"><i>sysconf</i>()</a>:</p>

<p><br>
 _SC_2_C_BIND<br>
_SC_2_C_DEV<br>
_SC_2_C_VERSION<br>
_SC_2_CHAR_TERM<br>
_SC_2_FORT_DEV<br>
_SC_2_FORT_RUN<br>
_SC_2_LOCALEDEF<br>
_SC_2_PBS<br>
_SC_2_PBS_ACCOUNTING<br>
_SC_2_PBS_CHECKPOINT<br>
_SC_2_PBS_LOCATE<br>
_SC_2_PBS_MESSAGE<br>
_SC_2_PBS_TRACK<br>
_SC_2_SW_DEV<br>
_SC_2_UPE<br>
_SC_2_VERSION<br>
_SC_ADVISORY_INFO<br>
_SC_ARG_MAX<br>
_SC_AIO_LISTIO_MAX<br>
_SC_AIO_MAX<br>
_SC_AIO_PRIO_DELTA_MAX<br>
_SC_ASYNCHRONOUS_IO<br>
_SC_ATEXIT_MAX<br>
_SC_BARRIERS<br>
_SC_BC_BASE_MAX<br>
_SC_BC_DIM_MAX<br>
_SC_BC_SCALE_MAX<br>
_SC_BC_STRING_MAX<br>
_SC_CHILD_MAX<br>
_SC_CLK_TCK<br>
_SC_CLOCK_SELECTION<br>
_SC_COLL_WEIGHTS_MAX<br>
_SC_CPUTIME<br>
_SC_DELAYTIMER_MAX<br>
_SC_EXPR_NEST_MAX<br>
_SC_FILE_LOCKING<br>
_SC_FSYNC<br>
_SC_GETGR_R_SIZE_MAX<br>
_SC_GETPW_R_SIZE_MAX<br>
_SC_HOST_NAME_MAX<br>
_SC_IOV_MAX<br>
_SC_IPV6<br>
_SC_JOB_CONTROL<br>
_SC_LINE_MAX<br>
_SC_LOGIN_NAME_MAX<br>
_SC_MAPPED_FILES<br>
_SC_MEMLOCK<br>
_SC_MEMLOCK_RANGE<br>
_SC_MEMORY_PROTECTION<br>
_SC_MESSAGE_PASSING<br>
_SC_MONOTONIC_CLOCK<br>
_SC_MQ_OPEN_MAX<br>
_SC_MQ_PRIO_MAX<br>
_SC_NGROUPS_MAX<br>
_SC_OPEN_MAX<br>
_SC_PAGE_SIZE<br>
_SC_PAGESIZE<br>
_SC_PRIORITIZED_IO<br>
_SC_PRIORITY_SCHEDULING<br>
_SC_RAW_SOCKETS<br>
_SC_RE_DUP_MAX<br>
_SC_READER_WRITER_LOCKS<br>
_SC_REALTIME_SIGNALS<br>
_SC_REGEXP<br>
_SC_RTSIG_MAX<br>
_SC_SAVED_IDS<br>
_SC_SEMAPHORES<br>
_SC_SEM_NSEMS_MAX<br>
_SC_SEM_VALUE_MAX<br>
_SC_SHARED_MEMORY_OBJECTS<br>
_SC_SHELL<br>
_SC_SIGQUEUE_MAX<br>
_SC_SPAWN<br>
_SC_SPIN_LOCKS<br>
_SC_SPORADIC_SERVER<br>
_SC_STREAM_MAX<br>
_SC_SYMLOOP_MAX<br>
_SC_SYNCHRONIZED_IO<br>
_SC_THREAD_ATTR_STACKADDR<br>
_SC_THREAD_ATTR_STACKSIZE<br>
_SC_THREAD_CPUTIME<br>
_SC_THREAD_DESTRUCTOR_ITERATIONS<br>
_SC_THREAD_KEYS_MAX<br>
_SC_THREAD_PRIO_INHERIT<br>
_SC_THREAD_PRIO_PROTECT<br>
_SC_THREAD_PRIORITY_SCHEDULING<br>
_SC_THREAD_PROCESS_SHARED<br>
_SC_THREAD_SAFE_FUNCTIONS<br>
_SC_THREAD_SPORADIC_SERVER<br>
_SC_THREAD_STACK_MIN<br>
_SC_THREAD_THREADS_MAX<br>
_SC_TIMEOUTS<br>
_SC_THREADS<br>
_SC_TIMER_MAX<br>
_SC_TIMERS<br>
_SC_TRACE<br>
_SC_TRACE_EVENT_FILTER<br>
_SC_TRACE_INHERIT<br>
_SC_TRACE_LOG<br>
_SC_TTY_NAME_MAX<br>
_SC_TYPED_MEMORY_OBJECTS<br>
_SC_TZNAME_MAX<br>
_SC_V6_ILP32_OFF32<br>
_SC_V6_ILP32_OFFBIG<br>
_SC_V6_LP64_OFF64<br>
_SC_V6_LPBIG_OFFBIG<br>
_SC_VERSION<br>
_SC_XBS5_ILP32_OFF32 (<b>LEGACY</b>)<br>
_SC_XBS5_ILP32_OFFBIG (<b>LEGACY</b>)<br>
_SC_XBS5_LP64_OFF64 (<b>LEGACY</b>)<br>
_SC_XBS5_LPBIG_OFFBIG (<b>LEGACY</b>)<br>
_SC_XOPEN_CRYPT<br>
_SC_XOPEN_ENH_I18N<br>
_SC_XOPEN_LEGACY<br>
_SC_XOPEN_REALTIME<br>
_SC_XOPEN_REALTIME_THREADS<br>
_SC_XOPEN_SHM<br>
_SC_XOPEN_STREAMS<br>
_SC_XOPEN_UNIX<br>
_SC_XOPEN_VERSION<br>
_SC_XOPEN_XCU_VERSION<br>
</p>

<p>The two constants _SC_PAGESIZE and _SC_PAGE_SIZE may be defined to have the same value.</p>

<p>The following symbolic constants shall be defined for file streams:</p>

<dl compact>
<dt>STDERR_FILENO</dt>

<dd>File number of <i>stderr</i>; 2.</dd>

<dt>STDIN_FILENO</dt>

<dd>File number of <i>stdin</i>; 0.</dd>

<dt>STDOUT_FILENO</dt>

<dd>File number of <i>stdout</i>; 1.</dd>
</dl>

<h5><a name="tag_13_80_03_05"></a>Type Definitions</h5>

<p>The <b>size_t</b>, <b>ssize_t</b>, <b>uid_t</b>, <b>gid_t</b>, <b>off_t</b>, <b>pid_t</b>, and <b>useconds_t</b> types shall be
defined as described in <a href="../basedefs/sys/types.h.html"><i>&lt;sys/types.h&gt;</i></a>.</p>

<p>The <b>intptr_t</b> type shall be defined as described in <a href=
"../basedefs/inttypes.h.html"><i>&lt;inttypes.h&gt;</i></a>.</p>

<h5><a name="tag_13_80_03_06"></a>Declarations</h5>

<p>The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.</p>

<pre>
<tt>int          access(const char *, int);
unsigned     alarm(unsigned);
int          chdir(const char *);
int          chown(const char *, uid_t, gid_t);
int          close(int);
size_t       confstr(int, char *, size_t);
<br>
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
char        *crypt(const char *, const char *);
char        *ctermid(char *);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
int          dup(int);
<br>
int          dup2(int, int);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
void         encrypt(char[64], int);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
int          execl(const char *, const char *, ...);
int          execle(const char *, const char *, ...);
int          execlp(const char *, const char *, ...);
int          execv(const char *, char *const []);
int          execve(const char *, char *const [], char *const []);
int          execvp(const char *, char *const []);
void        _exit(int);
int          fchown(int, uid_t, gid_t);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
int          fchdir(int);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
<sup>[<a href="javascript:open_code('SIO')">SIO</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
int          fdatasync(int);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
pid_t        fork(void);
long         fpathconf(int, int);
<sup>[<a href="javascript:open_code('FSC')">FSC</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
int          fsync(int);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
int          ftruncate(int, off_t);
char        *getcwd(char *, size_t);
gid_t        getegid(void);
uid_t        geteuid(void);
gid_t        getgid(void);
int          getgroups(int, gid_t []);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
long         gethostid(void);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
int          gethostname(char *, size_t);
char        *getlogin(void);
int          getlogin_r(char *, size_t);
int          getopt(int, char * const [], const char *);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
pid_t        getpgid(pid_t);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
pid_t        getpgrp(void);
pid_t        getpid(void);
pid_t        getppid(void);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
pid_t        getsid(pid_t);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
uid_t        getuid(void);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
char        *getwd(char *); (</tt><b>LEGACY</b> <tt>)
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
int          isatty(int);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
int          lchown(const char *, uid_t, gid_t);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
int          link(const char *, const char *);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
int          lockf(int, int, off_t);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
off_t        lseek(int, off_t, int);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
int          nice(int);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
long         pathconf(const char *, int);
int          pause(void);
int          pipe(int [2]);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
ssize_t      pread(int, void *, size_t, off_t);
ssize_t      pwrite(int, const void *, size_t, off_t);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
ssize_t      read(int, void *, size_t);
ssize_t      readlink(const char *restrict, char *restrict, size_t);
int          rmdir(const char *);
int          setegid(gid_t);
int          seteuid(uid_t);
int          setgid(gid_t);
<br>
int          setpgid(pid_t, pid_t);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
pid_t        setpgrp(void);
int          setregid(gid_t, gid_t);
int          setreuid(uid_t, uid_t);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
pid_t        setsid(void);
int          setuid(uid_t);
unsigned     sleep(unsigned);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
void         swab(const void *restrict, void *restrict, ssize_t);
int          symlink(const char *, const char *);
void         sync(void);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
long         sysconf(int);
pid_t        tcgetpgrp(int);
int          tcsetpgrp(int, pid_t);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
int          truncate(const char *, off_t);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
char        *ttyname(int);
int          ttyname_r(int, char *, size_t);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
useconds_t   ualarm(useconds_t, useconds_t);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
int          unlink(const char *);
<sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup><img src="../images/opt-start.gif" alt="[Option Start]" border="0">
int          usleep(useconds_t);
pid_t        vfork(void);
<img src="../images/opt-end.gif" alt="[Option End]" border="0">
ssize_t      write(int, const void *, size_t);
</tt>
</pre>

<p>Implementations may also include the <a href="../functions/pthread_atfork.html"><i>pthread_atfork</i>()</a> prototype as defined
in <a href="pthread.h.html"><i>&lt;pthread.h&gt;</i></a> .</p>

<p>The following external variables shall be declared:</p>

<pre>
<tt>extern char  *optarg;