POSIX(category15-traffic.html) - phpMan

POSIX(3pm)             Perl Programmers Reference Guide             POSIX(3pm)

NAME
       POSIX - Perl interface to IEEE Std 1003.1
SYNOPSIS
           use POSIX ();
           use POSIX qw(setsid);
           use POSIX qw(:errno_h :fcntl_h);
           printf "EINTR is %d\n", EINTR;
           $sess_id = POSIX::setsid();
           $fd = POSIX::open($path, O_CREAT|O_EXCL|O_WRONLY, 0644);
               # note: that's a filedescriptor, *NOT* a filehandle
DESCRIPTION
       The POSIX module permits you to access all (or nearly all) the standard
       POSIX 1003.1 identifiers.  Many of these identifiers have been given
       Perl-ish interfaces.
       Everything is exported by default with the exception of any POSIX
       functions with the same name as a built-in Perl function, such as
       "abs", "alarm", "rmdir", "write", etc.., which will be exported only if
       you ask for them explicitly.  This is an unfortunate backwards
       compatibility feature.  You can stop the exporting by saying "use POSIX
       ()" and then use the fully qualified names (ie. "POSIX::SEEK_END"), or
       by giving an explicit import list.  If you do neither, and opt for the
       default, "use POSIX;" has to import 553 symbols.
       This document gives a condensed list of the features available in the
       POSIX module.  Consult your operating system's manpages for general
       information on most features.  Consult perlfunc for functions which are
       noted as being identical to Perl's builtin functions.
       The first section describes POSIX functions from the 1003.1
       specification.  The second section describes some classes for signal
       objects, TTY objects, and other miscellaneous objects.  The remaining
       sections list various constants and macros in an organization which
       roughly follows IEEE Std 1003.1b-1993.
CAVEATS
       A few functions are not implemented because they are C specific.  If
       you attempt to call these, they will print a message telling you that
       they aren't implemented, and suggest using the Perl equivalent should
       one exist.  For example, trying to access the setjmp() call will elicit
       the message "setjmp() is C-specific: use eval {} instead".
       Furthermore, some evil vendors will claim 1003.1 compliance, but in
       fact are not so: they will not pass the PCTS (POSIX Compliance Test
       Suites).  For example, one vendor may not define EDEADLK, or the
       semantics of the errno values set by open(2) might not be quite right.
       Perl does not attempt to verify POSIX compliance.  That means you can
       currently successfully say "use POSIX",  and then later in your program
       you find that your vendor has been lax and there's no usable ICANON
       macro after all.  This could be construed to be a bug.
FUNCTIONS
       _exit   This is identical to the C function "_exit()".  It exits the
               program immediately which means among other things buffered I/O
               is not flushed.
               Note that when using threads and in Linux this is not a good
               way to exit a thread because in Linux processes and threads are
               kind of the same thing (Note: while this is the situation in
               early 2003 there are projects under way to have threads with
               more POSIXly semantics in Linux).  If you want not to return
               from a thread, detach the thread.
       abort   This is identical to the C function "abort()".  It terminates
               the process with a "SIGABRT" signal unless caught by a signal
               handler or if the handler does not return normally (it e.g.
               does a "longjmp").
       abs     This is identical to Perl's builtin "abs()" function, returning
               the absolute value of its numerical argument.
       access  Determines the accessibility of a file.
                       if( POSIX::access( "/", &POSIX::R_OK ) ){
                               print "have read permission\n";
                       }
               Returns "undef" on failure.  Note: do not use "access()" for
               security purposes.  Between the "access()" call and the
               operation you are preparing for the permissions might change: a
               classic race condition.
       acos    This is identical to the C function "acos()", returning the
               arcus cosine of its numerical argument.  See also Math::Trig.
       alarm   This is identical to Perl's builtin "alarm()" function, either
               for arming or disarming the "SIGARLM" timer.
       asctime This is identical to the C function "asctime()".  It returns a
               string of the form
                       "Fri Jun  2 18:22:13 2000\n\0"
               and it is called thusly
                       $asctime = asctime($sec, $min, $hour, $mday, $mon, $year,
                                          $wday, $yday, $isdst);
               The $mon is zero-based: January equals 0.  The $year is
               1900-based: 2001 equals 101.  $wday and $yday default to zero
               (and are usually ignored anyway), and $isdst defaults to -1.
       asin    This is identical to the C function "asin()", returning the
               arcus sine of its numerical argument.  See also Math::Trig.
       assert  Unimplemented, but you can use "die" in perlfunc and the Carp
               module to achieve similar things.
       atan    This is identical to the C function "atan()", returning the
               arcus tangent of its numerical argument.  See also Math::Trig.
       atan2   This is identical to Perl's builtin "atan2()" function,
               returning the arcus tangent defined by its two numerical
               arguments, the y coordinate and the x coordinate.  See also
               Math::Trig.
       atexit  atexit() is C-specific: use "END {}" instead, see perlsub.
       atof    atof() is C-specific.  Perl converts strings to numbers
               transparently.  If you need to force a scalar to a number, add
               a zero to it.
       atoi    atoi() is C-specific.  Perl converts strings to numbers
               transparently.  If you need to force a scalar to a number, add
               a zero to it.  If you need to have just the integer part, see
               "int" in perlfunc.
       atol    atol() is C-specific.  Perl converts strings to numbers
               transparently.  If you need to force a scalar to a number, add
               a zero to it.  If you need to have just the integer part, see
               "int" in perlfunc.
       bsearch bsearch() not supplied.  For doing binary search on wordlists,
               see Search::Dict.
       calloc  calloc() is C-specific.  Perl does memory management
               transparently.
       ceil    This is identical to the C function "ceil()", returning the
               smallest integer value greater than or equal to the given
               numerical argument.
       chdir   This is identical to Perl's builtin "chdir()" function,
               allowing one to change the working (default) directory, see
               "chdir" in perlfunc.
       chmod   This is identical to Perl's builtin "chmod()" function,
               allowing one to change file and directory permissions, see
               "chmod" in perlfunc.
       chown   This is identical to Perl's builtin "chown()" function,
               allowing one to change file and directory owners and groups,
               see "chown" in perlfunc.
       clearerr
               Use the method "IO::Handle::clearerr()" instead, to reset the
               error state (if any) and EOF state (if any) of the given
               stream.
       clock   This is identical to the C function "clock()", returning the
               amount of spent processor time in microseconds.
       close   Close the file.  This uses file descriptors such as those
               obtained by calling "POSIX::open".
                       $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
                       POSIX::close( $fd );
               Returns "undef" on failure.
               See also "close" in perlfunc.
       closedir
               This is identical to Perl's builtin "closedir()" function for
               closing a directory handle, see "closedir" in perlfunc.
       cos     This is identical to Perl's builtin "cos()" function, for
               returning the cosine of its numerical argument, see "cos" in
               perlfunc.  See also Math::Trig.
       cosh    This is identical to the C function "cosh()", for returning the
               hyperbolic cosine of its numeric argument.  See also
               Math::Trig.
       creat   Create a new file.  This returns a file descriptor like the
               ones returned by "POSIX::open".  Use "POSIX::close" to close
               the file.
                       $fd = POSIX::creat( "foo", 0611 );
                       POSIX::close( $fd );
               See also "sysopen" in perlfunc and its "O_CREAT" flag.
       ctermid Generates the path name for the controlling terminal.
                       $path = POSIX::ctermid();
       ctime   This is identical to the C function "ctime()" and equivalent to
               "asctime(localtime(...))", see "asctime" and "localtime".
       cuserid Get the login name of the owner of the current process.
                       $name = POSIX::cuserid();
       difftime
               This is identical to the C function "difftime()", for returning
               the time difference (in seconds) between two times (as returned
               by "time()"), see "time".
       div     div() is C-specific, use "int" in perlfunc on the usual "/"
               division and the modulus "%".
       dup     This is similar to the C function "dup()", for duplicating a
               file descriptor.
               This uses file descriptors such as those obtained by calling
               "POSIX::open".
               Returns "undef" on failure.
       dup2    This is similar to the C function "dup2()", for duplicating a
               file descriptor to an another known file descriptor.
               This uses file descriptors such as those obtained by calling
               "POSIX::open".
               Returns "undef" on failure.
       errno   Returns the value of errno.
                       $errno = POSIX::errno();
               This identical to the numerical values of the $!, see "$ERRNO"
               in perlvar.
       execl   execl() is C-specific, see "exec" in perlfunc.
       execle  execle() is C-specific, see "exec" in perlfunc.
       execlp  execlp() is C-specific, see "exec" in perlfunc.
       execv   execv() is C-specific, see "exec" in perlfunc.
       execve  execve() is C-specific, see "exec" in perlfunc.
       execvp  execvp() is C-specific, see "exec" in perlfunc.
       exit    This is identical to Perl's builtin "exit()" function for
               exiting the program, see "exit" in perlfunc.
       exp     This is identical to Perl's builtin "exp()" function for
               returning the exponent (e-based) of the numerical argument, see
               "exp" in perlfunc.
       fabs    This is identical to Perl's builtin "abs()" function for
               returning the absolute value of the numerical argument, see
               "abs" in perlfunc.
       fclose  Use method "IO::Handle::close()" instead, or see "close" in
               perlfunc.
       fcntl   This is identical to Perl's builtin "fcntl()" function, see
               "fcntl" in perlfunc.
       fdopen  Use method "IO::Handle::new_from_fd()" instead, or see "open"
               in perlfunc.
       feof    Use method "IO::Handle::eof()" instead, or see "eof" in
               perlfunc.
       ferror  Use method "IO::Handle::error()" instead.
       fflush  Use method "IO::Handle::flush()" instead.  See also
               "$OUTPUT_AUTOFLUSH" in perlvar.
       fgetc   Use method "IO::Handle::getc()" instead, or see "read" in
               perlfunc.
       fgetpos Use method "IO::Seekable::getpos()" instead, or see "seek" in
               perlfunc.
       fgets   Use method "IO::Handle::gets()" instead.  Similar to <>, also
               known as "readline" in perlfunc.
       fileno  Use method "IO::Handle::fileno()" instead, or see "fileno" in
               perlfunc.
       floor   This is identical to the C function "floor()", returning the
               largest integer value less than or equal to the numerical
               argument.
       fmod    This is identical to the C function "fmod()".
                       $r = fmod($x, $y);
               It returns the remainder "$r = $x - $n*$y", where "$n =
               trunc($x/$y)".  The $r has the same sign as $x and magnitude
               (absolute value) less than the magnitude of $y.
       fopen   Use method "IO::File::open()" instead, or see "open" in
               perlfunc.
       fork    This is identical to Perl's builtin "fork()" function for
               duplicating the current process, see "fork" in perlfunc and
               perlfork if you are in Windows.
       fpathconf
               Retrieves the value of a configurable limit on a file or
               directory.  This uses file descriptors such as those obtained
               by calling "POSIX::open".
               The following will determine the maximum length of the longest
               allowable pathname on the filesystem which holds "/var/foo".
                       $fd = POSIX::open( "/var/foo", &POSIX::O_RDONLY );
                       $path_max = POSIX::fpathconf( $fd, &POSIX::_PC_PATH_MAX );
               Returns "undef" on failure.
       fprintf fprintf() is C-specific, see "printf" in perlfunc instead.
       fputc   fputc() is C-specific, see "print" in perlfunc instead.
       fputs   fputs() is C-specific, see "print" in perlfunc instead.
       fread   fread() is C-specific, see "read" in perlfunc instead.
       free    free() is C-specific.  Perl does memory management
               transparently.
       freopen freopen() is C-specific, see "open" in perlfunc instead.
       frexp   Return the mantissa and exponent of a floating-point number.
                       ($mantissa, $exponent) = POSIX::frexp( 1.234e56 );
       fscanf  fscanf() is C-specific, use <> and regular expressions instead.
       fseek   Use method "IO::Seekable::seek()" instead, or see "seek" in
               perlfunc.
       fsetpos Use method "IO::Seekable::setpos()" instead, or seek "seek" in
               perlfunc.
       fstat   Get file status.  This uses file descriptors such as those
               obtained by calling "POSIX::open".  The data returned is
               identical to the data from Perl's builtin "stat" function.
                       $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
                       @stats = POSIX::fstat( $fd );
       fsync   Use method "IO::Handle::sync()" instead.
       ftell   Use method "IO::Seekable::tell()" instead, or see "tell" in
               perlfunc.
       fwrite  fwrite() is C-specific, see "print" in perlfunc instead.
       getc    This is identical to Perl's builtin "getc()" function, see
               "getc" in perlfunc.
       getchar Returns one character from STDIN.  Identical to Perl's
               "getc()", see "getc" in perlfunc.
       getcwd  Returns the name of the current working directory.  See also
               Cwd.
       getegid Returns the effective group identifier.  Similar to Perl' s
               builtin variable $(, see "$EGID" in perlvar.
       getenv  Returns the value of the specified environment variable.  The
               same information is available through the %ENV array.
       geteuid Returns the effective user identifier.  Identical to Perl's
               builtin $> variable, see "$EUID" in perlvar.
       getgid  Returns the user's real group identifier.  Similar to Perl's
               builtin variable $), see "$GID" in perlvar.
       getgrgid
               This is identical to Perl's builtin "getgrgid()" function for
               returning group entries by group identifiers, see "getgrgid" in
               perlfunc.
       getgrnam
               This is identical to Perl's builtin "getgrnam()" function for
               returning group entries by group names, see "getgrnam" in
               perlfunc.
       getgroups
               Returns the ids of the user's supplementary groups.  Similar to
               Perl's builtin variable $), see "$GID" in perlvar.
       getlogin
               This is identical to Perl's builtin "getlogin()" function for
               returning the user name associated with the current session,
               see "getlogin" in perlfunc.
       getpgrp This is identical to Perl's builtin "getpgrp()" function for
               returning the process group identifier of the current process,
               see "getpgrp" in perlfunc.
       getpid  Returns the process identifier.  Identical to Perl's builtin
               variable $$, see "$PID" in perlvar.
       getppid This is identical to Perl's builtin "getppid()" function for
               returning the process identifier of the parent process of the
               current process , see "getppid" in perlfunc.
       getpwnam
               This is identical to Perl's builtin "getpwnam()" function for
               returning user entries by user names, see "getpwnam" in
               perlfunc.
       getpwuid
               This is identical to Perl's builtin "getpwuid()" function for
               returning user entries by user identifiers, see "getpwuid" in
               perlfunc.
       gets    Returns one line from "STDIN", similar to <>, also known as the
               "readline()" function, see "readline" in perlfunc.
               NOTE: if you have C programs that still use "gets()", be very
               afraid.  The "gets()" function is a source of endless grief
               because it has no buffer overrun checks.  It should never be
               used.  The "fgets()" function should be preferred instead.
       getuid  Returns the user's identifier.  Identical to Perl's builtin $<
               variable, see "$UID" in perlvar.
       gmtime  This is identical to Perl's builtin "gmtime()" function for
               converting seconds since the epoch to a date in Greenwich Mean
               Time, see "gmtime" in perlfunc.
       isalnum This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "isalnum".
               Does not work on Unicode characters code point 256 or higher.
               Consider using regular expressions and the "/[[:alnum:]]/"
               construct instead, or possibly the "/\w/" construct.
       isalpha This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "isalpha".
               Does not work on Unicode characters code point 256 or higher.
               Consider using regular expressions and the "/[[:alpha:]]/"
               construct instead.
       isatty  Returns a boolean indicating whether the specified filehandle
               is connected to a tty.  Similar to the "-t" operator, see "-X"
               in perlfunc.
       iscntrl This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "iscntrl".
               Does not work on Unicode characters code point 256 or higher.
               Consider using regular expressions and the "/[[:cntrl:]]/"
               construct instead.
       isdigit This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "isdigit"
               (unlikely, but still possible). Does not work on Unicode
               characters code point 256 or higher.  Consider using regular
               expressions and the "/[[:digit:]]/" construct instead, or the
               "/\d/" construct.
       isgraph This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "isgraph".
               Does not work on Unicode characters code point 256 or higher.
               Consider using regular expressions and the "/[[:graph:]]/"
               construct instead.
       islower This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "islower".
               Does not work on Unicode characters code point 256 or higher.
               Consider using regular expressions and the "/[[:lower:]]/"
               construct instead.  Do not use "/[a-z]/".
       isprint This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "isprint".
               Does not work on Unicode characters code point 256 or higher.
               Consider using regular expressions and the "/[[:print:]]/"
               construct instead.
       ispunct This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "ispunct".
               Does not work on Unicode characters code point 256 or higher.
               Consider using regular expressions and the "/[[:punct:]]/"
               construct instead.
       isspace This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "isspace".
               Does not work on Unicode characters code point 256 or higher.
               Consider using regular expressions and the "/[[:space:]]/"
               construct instead, or the "/\s/" construct.  (Note that "/\s/"
               and "/[[:space:]]/" are slightly different in that
               "/[[:space:]]/" can normally match a vertical tab, while "/\s/"
               does not.)
       isupper This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "isupper".
               Does not work on Unicode characters code point 256 or higher.
               Consider using regular expressions and the "/[[:upper:]]/"
               construct instead.  Do not use "/[A-Z]/".
       isxdigit
               This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Note that locale
               settings may affect what characters are considered "isxdigit"
               (unlikely, but still possible).  Does not work on Unicode
               characters code point 256 or higher.  Consider using regular
               expressions and the "/[[:xdigit:]]/" construct instead, or
               simply "/[0-9a-f]/i".
       kill    This is identical to Perl's builtin "kill()" function for
               sending signals to processes (often to terminate them), see
               "kill" in perlfunc.
       labs    (For returning absolute values of long integers.)  labs() is
               C-specific, see "abs" in perlfunc instead.
       lchown  This is identical to the C function, except the order of
               arguments is consistent with Perl's builtin "chown()" with the
               added restriction of only one path, not an list of paths.  Does
               the same thing as the "chown()" function but changes the owner
               of a symbolic link instead of the file the symbolic link points
               to.
       ldexp   This is identical to the C function "ldexp()" for multiplying
               floating point numbers with powers of two.
                       $x_quadrupled = POSIX::ldexp($x, 2);
       ldiv    (For computing dividends of long integers.)  ldiv() is
               C-specific, use "/" and "int()" instead.
       link    This is identical to Perl's builtin "link()" function for
               creating hard links into files, see "link" in perlfunc.
       localeconv
               Get numeric formatting information.  Returns a reference to a
               hash containing the current locale formatting values.
               Here is how to query the database for the de (Deutsch or
               German) locale.
                       $loc = POSIX::setlocale( &POSIX::LC_ALL, "de" );
                       print "Locale = $loc\n";
                       $lconv = POSIX::localeconv();
                       print "decimal_point    = ", $lconv->{decimal_point},   "\n";
                       print "thousands_sep    = ", $lconv->{thousands_sep},   "\n";
                       print "grouping = ", $lconv->{grouping},        "\n";
                       print "int_curr_symbol  = ", $lconv->{int_curr_symbol}, "\n";
                       print "currency_symbol  = ", $lconv->{currency_symbol}, "\n";
                       print "mon_decimal_point = ", $lconv->{mon_decimal_point}, "\n";
                       print "mon_thousands_sep = ", $lconv->{mon_thousands_sep}, "\n";
                       print "mon_grouping     = ", $lconv->{mon_grouping},    "\n";
                       print "positive_sign    = ", $lconv->{positive_sign},   "\n";
                       print "negative_sign    = ", $lconv->{negative_sign},   "\n";
                       print "int_frac_digits  = ", $lconv->{int_frac_digits}, "\n";
                       print "frac_digits      = ", $lconv->{frac_digits},     "\n";
                       print "p_cs_precedes    = ", $lconv->{p_cs_precedes},   "\n";
                       print "p_sep_by_space   = ", $lconv->{p_sep_by_space},  "\n";
                       print "n_cs_precedes    = ", $lconv->{n_cs_precedes},   "\n";
                       print "n_sep_by_space   = ", $lconv->{n_sep_by_space},  "\n";
                       print "p_sign_posn      = ", $lconv->{p_sign_posn},     "\n";
                       print "n_sign_posn      = ", $lconv->{n_sign_posn},     "\n";
       localtime
               This is identical to Perl's builtin "localtime()" function for
               converting seconds since the epoch to a date see "localtime" in
               perlfunc.
       log     This is identical to Perl's builtin "log()" function, returning
               the natural (e-based) logarithm of the numerical argument, see
               "log" in perlfunc.
       log10   This is identical to the C function "log10()", returning the
               10-base logarithm of the numerical argument.  You can also use
                   sub log10 { log($_[0]) / log(10) }
               or
                   sub log10 { log($_[0]) / 2.30258509299405 }
               or
                   sub log10 { log($_[0]) * 0.434294481903252 }
       longjmp longjmp() is C-specific: use "die" in perlfunc instead.
       lseek   Move the file's read/write position.  This uses file
               descriptors such as those obtained by calling "POSIX::open".
                       $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
                       $off_t = POSIX::lseek( $fd, 0, &POSIX::SEEK_SET );
               Returns "undef" on failure.
       malloc  malloc() is C-specific.  Perl does memory management
               transparently.
       mblen   This is identical to the C function "mblen()".  Perl does not
               have any support for the wide and multibyte characters of the C
               standards, so this might be a rather useless function.
       mbstowcs
               This is identical to the C function "mbstowcs()".  Perl does
               not have any support for the wide and multibyte characters of
               the C standards, so this might be a rather useless function.
       mbtowc  This is identical to the C function "mbtowc()".  Perl does not
               have any support for the wide and multibyte characters of the C
               standards, so this might be a rather useless function.
       memchr  memchr() is C-specific, see "index" in perlfunc instead.
       memcmp  memcmp() is C-specific, use "eq" instead, see perlop.
       memcpy  memcpy() is C-specific, use "=", see perlop, or see "substr" in
               perlfunc.
       memmove memmove() is C-specific, use "=", see perlop, or see "substr"
               in perlfunc.
       memset  memset() is C-specific, use "x" instead, see perlop.
       mkdir   This is identical to Perl's builtin "mkdir()" function for
               creating directories, see "mkdir" in perlfunc.
       mkfifo  This is similar to the C function "mkfifo()" for creating FIFO
               special files.
                       if (mkfifo($path, $mode)) { ....
               Returns "undef" on failure.  The $mode is similar to the mode
               of "mkdir()", see "mkdir" in perlfunc, though for "mkfifo" you
               must specify the $mode.
       mktime  Convert date/time info to a calendar time.
               Synopsis:
                       mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = -1)
               The month ("mon"), weekday ("wday"), and yearday ("yday") begin
               at zero.  I.e. January is 0, not 1; Sunday is 0, not 1; January
               1st is 0, not 1.  The year ("year") is given in years since
               1900.  I.e. The year 1995 is 95; the year 2001 is 101.  Consult
               your system's "mktime()" manpage for details about these and
               the other arguments.
               Calendar time for December 12, 1995, at 10:30 am.
                       $time_t = POSIX::mktime( 0, 30, 10, 12, 11, 95 );
                       print "Date = ", POSIX::ctime($time_t);
               Returns "undef" on failure.
       modf    Return the integral and fractional parts of a floating-point
               number.
                       ($fractional, $integral) = POSIX::modf( 3.14 );
       nice    This is similar to the C function "nice()", for changing the
               scheduling preference of the current process.  Positive
               arguments mean more polite process, negative values more needy
               process.  Normal user processes can only be more polite.
               Returns "undef" on failure.
       offsetof
               offsetof() is C-specific, you probably want to see "pack" in
               perlfunc instead.
       open    Open a file for reading for writing.  This returns file
               descriptors, not Perl filehandles.  Use "POSIX::close" to close
               the file.
               Open a file read-only with mode 0666.
                       $fd = POSIX::open( "foo" );
               Open a file for read and write.
                       $fd = POSIX::open( "foo", &POSIX::O_RDWR );
               Open a file for write, with truncation.
                       $fd = POSIX::open( "foo", &POSIX::O_WRONLY | &POSIX::O_TRUNC );
               Create a new file with mode 0640.  Set up the file for writing.
                       $fd = POSIX::open( "foo", &POSIX::O_CREAT | &POSIX::O_WRONLY, 0640 );
               Returns "undef" on failure.
               See also "sysopen" in perlfunc.
       opendir Open a directory for reading.
                       $dir = POSIX::opendir( "/var" );
                       @files = POSIX::readdir( $dir );
                       POSIX::closedir( $dir );
               Returns "undef" on failure.
       pathconf
               Retrieves the value of a configurable limit on a file or
               directory.
               The following will determine the maximum length of the longest
               allowable pathname on the filesystem which holds "/var".
                       $path_max = POSIX::pathconf( "/var", &POSIX::_PC_PATH_MAX );
               Returns "undef" on failure.
       pause   This is similar to the C function "pause()", which suspends the
               execution of the current process until a signal is received.
               Returns "undef" on failure.
       perror  This is identical to the C function "perror()", which outputs
               to the standard error stream the specified message followed by
               ": " and the current error string.  Use the "warn()" function
               and the $!  variable instead, see "warn" in perlfunc and
               "$ERRNO" in perlvar.
       pipe    Create an interprocess channel.  This returns file descriptors
               like those returned by "POSIX::open".
                       my ($read, $write) = POSIX::pipe();
                       POSIX::write( $write, "hello", 5 );
                       POSIX::read( $read, $buf, 5 );
               See also "pipe" in perlfunc.
       pow     Computes $x raised to the power $exponent.
                       $ret = POSIX::pow( $x, $exponent );
               You can also use the "**" operator, see perlop.
       printf  Formats and prints the specified arguments to STDOUT.  See also
               "printf" in perlfunc.
       putc    putc() is C-specific, see "print" in perlfunc instead.
       putchar putchar() is C-specific, see "print" in perlfunc instead.
       puts    puts() is C-specific, see "print" in perlfunc instead.
       qsort   qsort() is C-specific, see "sort" in perlfunc instead.
       raise   Sends the specified signal to the current process.  See also
               "kill" in perlfunc and the $$ in "$PID" in perlvar.
       rand    "rand()" is non-portable, see "rand" in perlfunc instead.
       read    Read from a file.  This uses file descriptors such as those
               obtained by calling "POSIX::open".  If the buffer $buf is not
               large enough for the read then Perl will extend it to make room
               for the request.
                       $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
                       $bytes = POSIX::read( $fd, $buf, 3 );
               Returns "undef" on failure.
               See also "sysread" in perlfunc.
       readdir This is identical to Perl's builtin "readdir()" function for
               reading directory entries, see "readdir" in perlfunc.
       realloc realloc() is C-specific.  Perl does memory management
               transparently.
       remove  This is identical to Perl's builtin "unlink()" function for
               removing files, see "unlink" in perlfunc.
       rename  This is identical to Perl's builtin "rename()" function for
               renaming files, see "rename" in perlfunc.
       rewind  Seeks to the beginning of the file.
       rewinddir
               This is identical to Perl's builtin "rewinddir()" function for
               rewinding directory entry streams, see "rewinddir" in perlfunc.
       rmdir   This is identical to Perl's builtin "rmdir()" function for
               removing (empty) directories, see "rmdir" in perlfunc.
       scanf   scanf() is C-specific, use <> and regular expressions instead,
               see perlre.
       setgid  Sets the real group identifier and the effective group
               identifier for this process.  Similar to assigning a value to
               the Perl's builtin $) variable, see "$EGID" in perlvar, except
               that the latter will change only the real user identifier, and
               that the setgid() uses only a single numeric argument, as
               opposed to a space-separated list of numbers.
       setjmp  "setjmp()" is C-specific: use "eval {}" instead, see "eval" in
               perlfunc.
       setlocale
               Modifies and queries program's locale.  The following examples
               assume
                       use POSIX qw(setlocale LC_ALL LC_CTYPE);
               has been issued.
               The following will set the traditional UNIX system locale
               behavior (the second argument "C").
                       $loc = setlocale( LC_ALL, "C" );
               The following will query the current LC_CTYPE category.  (No
               second argument means 'query'.)
                       $loc = setlocale( LC_CTYPE );
               The following will set the LC_CTYPE behaviour according to the
               locale environment variables (the second argument "").  Please
               see your systems setlocale(3) documentation for the locale
               environment variables' meaning or consult perllocale.
                       $loc = setlocale( LC_CTYPE, "" );
               The following will set the LC_COLLATE behaviour to Argentinian
               Spanish. NOTE: The naming and availability of locales depends
               on your operating system. Please consult perllocale for how to
               find out which locales are available in your system.
                       $loc = setlocale( LC_COLLATE, "es_AR.ISO8859-1" );
       setpgid This is similar to the C function "setpgid()" for setting the
               process group identifier of the current process.
               Returns "undef" on failure.
       setsid  This is identical to the C function "setsid()" for setting the
               session identifier of the current process.
       setuid  Sets the real user identifier and the effective user identifier
               for this process.  Similar to assigning a value to the Perl's
               builtin $< variable, see "$UID" in perlvar, except that the
               latter will change only the real user identifier.
       sigaction
               Detailed signal management.  This uses "POSIX::SigAction"
               objects for the "action" and "oldaction" arguments (the
               oldaction can also be just a hash reference).  Consult your
               system's "sigaction" manpage for details, see also
               "POSIX::SigRt".
               Synopsis:
                       sigaction(signal, action, oldaction = 0)
               Returns "undef" on failure.  The "signal" must be a number
               (like SIGHUP), not a string (like "SIGHUP"), though Perl does
               try hard to understand you.
               If you use the SA_SIGINFO flag, the signal handler will in
               addition to the first argument, the signal name, also receive a
               second argument, a hash reference, inside which are the
               following keys with the following semantics, as defined by
               POSIX/SUSv3:
                   signo       the signal number
                   errno       the error number
                   code        if this is zero or less, the signal was sent by
                               a user process and the uid and pid make sense,
                               otherwise the signal was sent by the kernel
               The following are also defined by POSIX/SUSv3, but
               unfortunately not very widely implemented:
                   pid         the process id generating the signal
                   uid         the uid of the process id generating the signal
                   status      exit value or signal for SIGCHLD
                   band        band event for SIGPOLL
               A third argument is also passed to the handler, which contains
               a copy of the raw binary contents of the siginfo structure: if
               a system has some non-POSIX fields, this third argument is
               where to unpack() them from.
               Note that not all siginfo values make sense simultaneously
               (some are valid only for certain signals, for example), and not
               all values make sense from Perl perspective, you should to
               consult your system's "sigaction" and possibly also "siginfo"
               documentation.
       siglongjmp
               siglongjmp() is C-specific: use "die" in perlfunc instead.
       sigpending
               Examine signals that are blocked and pending.  This uses
               "POSIX::SigSet" objects for the "sigset" argument.  Consult
               your system's "sigpending" manpage for details.
               Synopsis:
                       sigpending(sigset)
               Returns "undef" on failure.
       sigprocmask
               Change and/or examine calling process's signal mask.  This uses
               "POSIX::SigSet" objects for the "sigset" and "oldsigset"
               arguments.  Consult your system's "sigprocmask" manpage for
               details.
               Synopsis:
                       sigprocmask(how, sigset, oldsigset = 0)
               Returns "undef" on failure.
               Note that you can't reliably block or unblock a signal from its
               own signal handler if you're using safe signals. Other signals
               can be blocked or unblocked reliably.
       sigsetjmp
               "sigsetjmp()" is C-specific: use "eval {}" instead, see "eval"
               in perlfunc.
       sigsuspend
               Install a signal mask and suspend process until signal arrives.
               This uses "POSIX::SigSet" objects for the "signal_mask"
               argument.  Consult your system's "sigsuspend" manpage for
               details.
               Synopsis:
                       sigsuspend(signal_mask)
               Returns "undef" on failure.
       sin     This is identical to Perl's builtin "sin()" function for
               returning the sine of the numerical argument, see "sin" in
               perlfunc.  See also Math::Trig.
       sinh    This is identical to the C function "sinh()" for returning the
               hyperbolic sine of the numerical argument.  See also
               Math::Trig.
       sleep   This is functionally identical to Perl's builtin "sleep()"
               function for suspending the execution of the current for
               process for certain number of seconds, see "sleep" in perlfunc.
               There is one significant difference, however: "POSIX::sleep()"
               returns the number of unslept seconds, while the
               "CORE::sleep()" returns the number of slept seconds.
       sprintf This is similar to Perl's builtin "sprintf()" function for
               returning a string that has the arguments formatted as
               requested, see "sprintf" in perlfunc.
       sqrt    This is identical to Perl's builtin "sqrt()" function.  for
               returning the square root of the numerical argument, see "sqrt"
               in perlfunc.
       srand   Give a seed the pseudorandom number generator, see "srand" in
               perlfunc.
       sscanf  sscanf() is C-specific, use regular expressions instead, see
               perlre.
       stat    This is identical to Perl's builtin "stat()" function for
               returning information about files and directories.
       strcat  strcat() is C-specific, use ".=" instead, see perlop.
       strchr  strchr() is C-specific, see "index" in perlfunc instead.
       strcmp  strcmp() is C-specific, use "eq" or "cmp" instead, see perlop.
       strcoll This is identical to the C function "strcoll()" for collating
               (comparing) strings transformed using the "strxfrm()" function.
               Not really needed since Perl can do this transparently, see
               perllocale.
       strcpy  strcpy() is C-specific, use "=" instead, see perlop.
       strcspn strcspn() is C-specific, use regular expressions instead, see
               perlre.
       strerror
               Returns the error string for the specified errno.  Identical to
               the string form of the $!, see "$ERRNO" in perlvar.
       strftime
               Convert date and time information to string.  Returns the
               string.
               Synopsis:
                       strftime(fmt, sec, min, hour, mday, mon, year, wday = -1, yday = -1, isdst = -1)
               The month ("mon"), weekday ("wday"), and yearday ("yday") begin
               at zero.  I.e. January is 0, not 1; Sunday is 0, not 1; January
               1st is 0, not 1.  The year ("year") is given in years since
               1900.  I.e., the year 1995 is 95; the year 2001 is 101.
               Consult your system's "strftime()" manpage for details about
               these and the other arguments.
               If you want your code to be portable, your format ("fmt")
               argument should use only the conversion specifiers defined by
               the ANSI C standard (C89, to play safe).  These are
               "aAbBcdHIjmMpSUwWxXyYZ%".  But even then, the results of some
               of the conversion specifiers are non-portable.  For example,
               the specifiers "aAbBcpZ" change according to the locale
               settings of the user, and both how to set locales (the locale
               names) and what output to expect are non-standard.  The
               specifier "c" changes according to the timezone settings of the
               user and the timezone computation rules of the operating
               system.  The "Z" specifier is notoriously unportable since the
               names of timezones are non-standard. Sticking to the numeric
               specifiers is the safest route.
               The given arguments are made consistent as though by calling
               "mktime()" before calling your system's "strftime()" function,
               except that the "isdst" value is not affected.
               The string for Tuesday, December 12, 1995.
                       $str = POSIX::strftime( "%A, %B %d, %Y", 0, 0, 0, 12, 11, 95, 2 );
                       print "$str\n";
       strlen  strlen() is C-specific, use "length()" instead, see "length" in
               perlfunc.
       strncat strncat() is C-specific, use ".=" instead, see perlop.
       strncmp strncmp() is C-specific, use "eq" instead, see perlop.
       strncpy strncpy() is C-specific, use "=" instead, see perlop.
       strpbrk strpbrk() is C-specific, use regular expressions instead, see
               perlre.
       strrchr strrchr() is C-specific, see "rindex" in perlfunc instead.
       strspn  strspn() is C-specific, use regular expressions instead, see
               perlre.
       strstr  This is identical to Perl's builtin "index()" function, see
               "index" in perlfunc.
       strtod  String to double translation. Returns the parsed number and the
               number of characters in the unparsed portion of the string.
               Truly POSIX-compliant systems set $! ($ERRNO) to indicate a
               translation error, so clear $! before calling strtod.  However,
               non-POSIX systems may not check for overflow, and therefore
               will never set $!.
               strtod should respect any POSIX setlocale() settings.
               To parse a string $str as a floating point number use
                   $! = 0;
                   ($num, $n_unparsed) = POSIX::strtod($str);
               The second returned item and $! can be used to check for valid
               input:
                   if (($str eq '') || ($n_unparsed != 0) || $!) {
                       die "Non-numeric input $str" . ($! ? ": $!\n" : "\n");
                   }
               When called in a scalar context strtod returns the parsed
               number.
       strtok  strtok() is C-specific, use regular expressions instead, see
               perlre, or "split" in perlfunc.
       strtol  String to (long) integer translation.  Returns the parsed
               number and the number of characters in the unparsed portion of
               the string.  Truly POSIX-compliant systems set $! ($ERRNO) to
               indicate a translation error, so clear $! before calling
               strtol.  However, non-POSIX systems may not check for overflow,
               and therefore will never set $!.
               strtol should respect any POSIX setlocale() settings.
               To parse a string $str as a number in some base $base use
                   $! = 0;
                   ($num, $n_unparsed) = POSIX::strtol($str, $base);
               The base should be zero or between 2 and 36, inclusive.  When
               the base is zero or omitted strtol will use the string itself
               to determine the base: a leading "0x" or "0X" means
               hexadecimal; a leading "0" means octal; any other leading
               characters mean decimal.  Thus, "1234" is parsed as a decimal
               number, "01234" as an octal number, and "0x1234" as a
               hexadecimal number.
               The second returned item and $! can be used to check for valid
               input:
                   if (($str eq '') || ($n_unparsed != 0) || !$!) {
                       die "Non-numeric input $str" . $! ? ": $!\n" : "\n";
                   }
               When called in a scalar context strtol returns the parsed
               number.
       strtoul String to unsigned (long) integer translation.  strtoul() is
               identical to strtol() except that strtoul() only parses
               unsigned integers.  See "strtol" for details.
               Note: Some vendors supply strtod() and strtol() but not
               strtoul().  Other vendors that do supply strtoul() parse "-1"
               as a valid value.
       strxfrm String transformation.  Returns the transformed string.
                       $dst = POSIX::strxfrm( $src );
               Used in conjunction with the "strcoll()" function, see
               "strcoll".
               Not really needed since Perl can do this transparently, see
               perllocale.
       sysconf Retrieves values of system configurable variables.
               The following will get the machine's clock speed.
                       $clock_ticks = POSIX::sysconf( &POSIX::_SC_CLK_TCK );
               Returns "undef" on failure.
       system  This is identical to Perl's builtin "system()" function, see
               "system" in perlfunc.
       tan     This is identical to the C function "tan()", returning the
               tangent of the numerical argument.  See also Math::Trig.
       tanh    This is identical to the C function "tanh()", returning the
               hyperbolic tangent of the numerical argument.   See also
               Math::Trig.
       tcdrain This is similar to the C function "tcdrain()" for draining the
               output queue of its argument stream.
               Returns "undef" on failure.
       tcflow  This is similar to the C function "tcflow()" for controlling
               the flow of its argument stream.
               Returns "undef" on failure.
       tcflush This is similar to the C function "tcflush()" for flushing the
               I/O buffers of its argument stream.
               Returns "undef" on failure.
       tcgetpgrp
               This is identical to the C function "tcgetpgrp()" for returning
               the process group identifier of the foreground process group of
               the controlling terminal.
       tcsendbreak
               This is similar to the C function "tcsendbreak()" for sending a
               break on its argument stream.
               Returns "undef" on failure.
       tcsetpgrp
               This is similar to the C function "tcsetpgrp()" for setting the
               process group identifier of the foreground process group of the
               controlling terminal.
               Returns "undef" on failure.
       time    This is identical to Perl's builtin "time()" function for
               returning the number of seconds since the epoch (whatever it is
               for the system), see "time" in perlfunc.
       times   The times() function returns elapsed realtime since some point
               in the past (such as system startup), user and system times for
               this process, and user and system times used by child
               processes.  All times are returned in clock ticks.
                   ($realtime, $user, $system, $cuser, $csystem) = POSIX::times();
               Note: Perl's builtin "times()" function returns four values,
               measured in seconds.
       tmpfile Use method "IO::File::new_tmpfile()" instead, or see
               File::Temp.
       tmpnam  Returns a name for a temporary file.
                       $tmpfile = POSIX::tmpnam();
               For security reasons, which are probably detailed in your
               system's documentation for the C library tmpnam() function,
               this interface should not be used; instead see File::Temp.
       tolower This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Consider using the
               "lc()" function, see "lc" in perlfunc, or the equivalent "\L"
               operator inside doublequotish strings.
       toupper This is identical to the C function, except that it can apply
               to a single character or to a whole string.  Consider using the
               "uc()" function, see "uc" in perlfunc, or the equivalent "\U"
               operator inside doublequotish strings.
       ttyname This is identical to the C function "ttyname()" for returning
               the name of the current terminal.
       tzname  Retrieves the time conversion information from the "tzname"
               variable.
                       POSIX::tzset();
                       ($std, $dst) = POSIX::tzname();
       tzset   This is identical to the C function "tzset()" for setting the
               current timezone based on the environment variable "TZ", to be
               used by "ctime()", "localtime()", "mktime()", and "strftime()"
               functions.
       umask   This is identical to Perl's builtin "umask()" function for
               setting (and querying) the file creation permission mask, see
               "umask" in perlfunc.
       uname   Get name of current operating system.
                       ($sysname, $nodename, $release, $version, $machine) = POSIX::uname();
               Note that the actual meanings of the various fields are not
               that well standardized, do not expect any great portability.
               The $sysname might be the name of the operating system, the
               $nodename might be the name of the host, the $release might be
               the (major) release number of the operating system, the
               $version might be the (minor) release number of the operating
               system, and the $machine might be a hardware identifier.
               Maybe.
       ungetc  Use method "IO::Handle::ungetc()" instead.
       unlink  This is identical to Perl's builtin "unlink()" function for
               removing files, see "unlink" in perlfunc.
       utime   This is identical to Perl's builtin "utime()" function for
               changing the time stamps of files and directories, see "utime"
               in perlfunc.
       vfprintf
               vfprintf() is C-specific, see "printf" in perlfunc instead.
       vprintf vprintf() is C-specific, see "printf" in perlfunc instead.
       vsprintf
               vsprintf() is C-specific, see "sprintf" in perlfunc instead.
       wait    This is identical to Perl's builtin "wait()" function, see
               "wait" in perlfunc.
       waitpid Wait for a child process to change state.  This is identical to
               Perl's builtin "waitpid()" function, see "waitpid" in perlfunc.
                       $pid = POSIX::waitpid( -1, POSIX::WNOHANG );
                       print "status = ", ($? / 256), "\n";
       wcstombs
               This is identical to the C function "wcstombs()".  Perl does
               not have any support for the wide and multibyte characters of
               the C standards, so this might be a rather useless function.
       wctomb  This is identical to the C function "wctomb()".  Perl does not
               have any support for the wide and multibyte characters of the C
               standards, so this might be a rather useless function.
       write   Write to a file.  This uses file descriptors such as those
               obtained by calling "POSIX::open".
                       $fd = POSIX::open( "foo", &POSIX::O_WRONLY );
                       $buf = "hello";
                       $bytes = POSIX::write( $fd, $buf, 5 );
               Returns "undef" on failure.
               See also "syswrite" in perlfunc.
CLASSES
   POSIX::SigAction
       new     Creates a new "POSIX::SigAction" object which corresponds to
               the C "struct sigaction".  This object will be destroyed
               automatically when it is no longer needed.  The first parameter
               is the handler, a sub reference.  The second parameter is a
               "POSIX::SigSet" object, it defaults to the empty set.  The
               third parameter contains the "sa_flags", it defaults to 0.
                       $sigset = POSIX::SigSet->new(SIGINT, SIGQUIT);
                       $sigaction = POSIX::SigAction->new( \&handler, $sigset, &POSIX::SA_NOCLDSTOP );
               This "POSIX::SigAction" object is intended for use with the
               "POSIX::sigaction()" function.
       handler
       mask
       flags   accessor functions to get/set the values of a SigAction object.
                       $sigset = $sigaction->mask;
                       $sigaction->flags(&POSIX::SA_RESTART);
       safe    accessor function for the "safe signals" flag of a SigAction
               object; see perlipc for general information on safe (a.k.a.
               "deferred") signals.  If you wish to handle a signal safely,
               use this accessor to set the "safe" flag in the
               "POSIX::SigAction" object:
                       $sigaction->safe(1);
               You may also examine the "safe" flag on the output action
               object which is filled in when given as the third parameter to
               "POSIX::sigaction()":
                       sigaction(SIGINT, $new_action, $old_action);
                       if ($old_action->safe) {
                           # previous SIGINT handler used safe signals
                       }
   POSIX::SigRt
       %SIGRT  A hash of the POSIX realtime signal handlers.  It is an
               extension of the standard %SIG, the $POSIX::SIGRT{SIGRTMIN} is
               roughly equivalent to $SIG{SIGRTMIN}, but the right POSIX moves
               (see below) are made with the POSIX::SigSet and
               POSIX::sigaction instead of accessing the %SIG.
               You can set the %POSIX::SIGRT elements to set the POSIX
               realtime signal handlers, use "delete" and "exists" on the
               elements, and use "scalar" on the %POSIX::SIGRT to find out how
               many POSIX realtime signals there are available (SIGRTMAX -
               SIGRTMIN + 1, the SIGRTMAX is a valid POSIX realtime signal).
               Setting the %SIGRT elements is equivalent to calling this:
                 sub new {
                   my ($rtsig, $handler, $flags) = @_;
                   my $sigset = POSIX::SigSet($rtsig);
                   my $sigact = POSIX::SigAction->new($handler, $sigset, $flags);
                   sigaction($rtsig, $sigact);
                 }
               The flags default to zero, if you want something different you
               can either use "local" on $POSIX::SigRt::SIGACTION_FLAGS, or
               you can derive from POSIX::SigRt and define your own "new()"
               (the tied hash STORE method of the %SIGRT calls "new($rtsig,
               $handler, $SIGACTION_FLAGS)", where the $rtsig ranges from zero
               to SIGRTMAX - SIGRTMIN + 1).
               Just as with any signal, you can use sigaction($rtsig, undef,
               $oa) to retrieve the installed signal handler (or, rather, the
               signal action).
               NOTE: whether POSIX realtime signals really work in your
               system, or whether Perl has been compiled so that it works with
               them, is outside of this discussion.
       SIGRTMIN
               Return the minimum POSIX realtime signal number available, or
               "undef" if no POSIX realtime signals are available.
       SIGRTMAX
               Return the maximum POSIX realtime signal number available, or
               "undef" if no POSIX realtime signals are available.
   POSIX::SigSet
       new     Create a new SigSet object.  This object will be destroyed
               automatically when it is no longer needed.  Arguments may be
               supplied to initialize the set.
               Create an empty set.
                       $sigset = POSIX::SigSet->new;
               Create a set with SIGUSR1.
                       $sigset = POSIX::SigSet->new( &POSIX::SIGUSR1 );
       addset  Add a signal to a SigSet object.
                       $sigset->addset( &POSIX::SIGUSR2 );
               Returns "undef" on failure.
       delset  Remove a signal from the SigSet object.
                       $sigset->delset( &POSIX::SIGUSR2 );
               Returns "undef" on failure.
       emptyset
               Initialize the SigSet object to be empty.
                       $sigset->emptyset();
               Returns "undef" on failure.
       fillset Initialize the SigSet object to include all signals.
                       $sigset->fillset();
               Returns "undef" on failure.
       ismember
               Tests the SigSet object to see if it contains a specific
               signal.
                       if( $sigset->ismember( &POSIX::SIGUSR1 ) ){
                               print "contains SIGUSR1\n";
                       }
   POSIX::Termios
       new     Create a new Termios object.  This object will be destroyed
               automatically when it is no longer needed.  A Termios object
               corresponds to the termios C struct.  new() mallocs a new one,
               getattr() fills it from a file descriptor, and setattr() sets a
               file descriptor's parameters to match Termios' contents.
                       $termios = POSIX::Termios->new;
       getattr Get terminal control attributes.
               Obtain the attributes for stdin.
                       $termios->getattr( 0 ) # Recommended for clarity.
                       $termios->getattr()
               Obtain the attributes for stdout.
                       $termios->getattr( 1 )
               Returns "undef" on failure.
       getcc   Retrieve a value from the c_cc field of a termios object.  The
               c_cc field is an array so an index must be specified.
                       $c_cc[1] = $termios->getcc(1);
       getcflag
               Retrieve the c_cflag field of a termios object.
                       $c_cflag = $termios->getcflag;
       getiflag
               Retrieve the c_iflag field of a termios object.
                       $c_iflag = $termios->getiflag;
       getispeed
               Retrieve the input baud rate.
                       $ispeed = $termios->getispeed;
       getlflag
               Retrieve the c_lflag field of a termios object.
                       $c_lflag = $termios->getlflag;
       getoflag
               Retrieve the c_oflag field of a termios object.
                       $c_oflag = $termios->getoflag;
       getospeed
               Retrieve the output baud rate.
                       $ospeed = $termios->getospeed;
       setattr Set terminal control attributes.
               Set attributes immediately for stdout.
                       $termios->setattr( 1, &POSIX::TCSANOW );
               Returns "undef" on failure.
       setcc   Set a value in the c_cc field of a termios object.  The c_cc
               field is an array so an index must be specified.
                       $termios->setcc( &POSIX::VEOF, 1 );
       setcflag
               Set the c_cflag field of a termios object.
                       $termios->setcflag( $c_cflag | &POSIX::CLOCAL );
       setiflag
               Set the c_iflag field of a termios object.
                       $termios->setiflag( $c_iflag | &POSIX::BRKINT );
       setispeed
               Set the input baud rate.
                       $termios->setispeed( &POSIX::B9600 );
               Returns "undef" on failure.
       setlflag
               Set the c_lflag field of a termios object.
                       $termios->setlflag( $c_lflag | &POSIX::ECHO );
       setoflag
               Set the c_oflag field of a termios object.
                       $termios->setoflag( $c_oflag | &POSIX::OPOST );
       setospeed
               Set the output baud rate.
                       $termios->setospeed( &POSIX::B9600 );
               Returns "undef" on failure.
       Baud rate values
               B38400 B75 B200 B134 B300 B1800 B150 B0 B19200 B1200 B9600 B600
               B4800 B50 B2400 B110
       Terminal interface values
               TCSADRAIN TCSANOW TCOON TCIOFLUSH TCOFLUSH TCION TCIFLUSH
               TCSAFLUSH TCIOFF TCOOFF
       c_cc field values
               VEOF VEOL VERASE VINTR VKILL VQUIT VSUSP VSTART VSTOP VMIN
               VTIME NCCS
       c_cflag field values
               CLOCAL CREAD CSIZE CS5 CS6 CS7 CS8 CSTOPB HUPCL PARENB PARODD
       c_iflag field values
               BRKINT ICRNL IGNBRK IGNCR IGNPAR INLCR INPCK ISTRIP IXOFF IXON
               PARMRK
       c_lflag field values
               ECHO ECHOE ECHOK ECHONL ICANON IEXTEN ISIG NOFLSH TOSTOP
       c_oflag field values
               OPOST
PATHNAME CONSTANTS
       Constants
               _PC_CHOWN_RESTRICTED _PC_LINK_MAX _PC_MAX_CANON _PC_MAX_INPUT
               _PC_NAME_MAX _PC_NO_TRUNC _PC_PATH_MAX _PC_PIPE_BUF
               _PC_VDISABLE
POSIX CONSTANTS
       Constants
               _POSIX_ARG_MAX _POSIX_CHILD_MAX _POSIX_CHOWN_RESTRICTED
               _POSIX_JOB_CONTROL _POSIX_LINK_MAX _POSIX_MAX_CANON
               _POSIX_MAX_INPUT _POSIX_NAME_MAX _POSIX_NGROUPS_MAX
               _POSIX_NO_TRUNC _POSIX_OPEN_MAX _POSIX_PATH_MAX _POSIX_PIPE_BUF
               _POSIX_SAVED_IDS _POSIX_SSIZE_MAX _POSIX_STREAM_MAX
               _POSIX_TZNAME_MAX _POSIX_VDISABLE _POSIX_VERSION
SYSTEM CONFIGURATION
       Constants
               _SC_ARG_MAX _SC_CHILD_MAX _SC_CLK_TCK _SC_JOB_CONTROL
               _SC_NGROUPS_MAX _SC_OPEN_MAX _SC_PAGESIZE _SC_SAVED_IDS
               _SC_STREAM_MAX _SC_TZNAME_MAX _SC_VERSION
ERRNO
       Constants
               E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EAFNOSUPPORT EAGAIN
               EALREADY EBADF EBUSY ECHILD ECONNABORTED ECONNREFUSED
               ECONNRESET EDEADLK EDESTADDRREQ EDOM EDQUOT EEXIST EFAULT EFBIG
               EHOSTDOWN EHOSTUNREACH EINPROGRESS EINTR EINVAL EIO EISCONN
               EISDIR ELOOP EMFILE EMLINK EMSGSIZE ENAMETOOLONG ENETDOWN
               ENETRESET ENETUNREACH ENFILE ENOBUFS ENODEV ENOENT ENOEXEC
               ENOLCK ENOMEM ENOPROTOOPT ENOSPC ENOSYS ENOTBLK ENOTCONN
               ENOTDIR ENOTEMPTY ENOTSOCK ENOTTY ENXIO EOPNOTSUPP EPERM
               EPFNOSUPPORT EPIPE EPROCLIM EPROTONOSUPPORT EPROTOTYPE ERANGE
               EREMOTE ERESTART EROFS ESHUTDOWN ESOCKTNOSUPPORT ESPIPE ESRCH
               ESTALE ETIMEDOUT ETOOMANYREFS ETXTBSY EUSERS EWOULDBLOCK EXDEV
FCNTL
       Constants
               FD_CLOEXEC F_DUPFD F_GETFD F_GETFL F_GETLK F_OK F_RDLCK F_SETFD
               F_SETFL F_SETLK F_SETLKW F_UNLCK F_WRLCK O_ACCMODE O_APPEND
               O_CREAT O_EXCL O_NOCTTY O_NONBLOCK O_RDONLY O_RDWR O_TRUNC
               O_WRONLY
FLOAT
       Constants
               DBL_DIG DBL_EPSILON DBL_MANT_DIG DBL_MAX DBL_MAX_10_EXP
               DBL_MAX_EXP DBL_MIN DBL_MIN_10_EXP DBL_MIN_EXP FLT_DIG
               FLT_EPSILON FLT_MANT_DIG FLT_MAX FLT_MAX_10_EXP FLT_MAX_EXP
               FLT_MIN FLT_MIN_10_EXP FLT_MIN_EXP FLT_RADIX FLT_ROUNDS
               LDBL_DIG LDBL_EPSILON LDBL_MANT_DIG LDBL_MAX LDBL_MAX_10_EXP
               LDBL_MAX_EXP LDBL_MIN LDBL_MIN_10_EXP LDBL_MIN_EXP
LIMITS
       Constants
               ARG_MAX CHAR_BIT CHAR_MAX CHAR_MIN CHILD_MAX INT_MAX INT_MIN
               LINK_MAX LONG_MAX LONG_MIN MAX_CANON MAX_INPUT MB_LEN_MAX
               NAME_MAX NGROUPS_MAX OPEN_MAX PATH_MAX PIPE_BUF SCHAR_MAX
               SCHAR_MIN SHRT_MAX SHRT_MIN SSIZE_MAX STREAM_MAX TZNAME_MAX
               UCHAR_MAX UINT_MAX ULONG_MAX USHRT_MAX
LOCALE
       Constants
               LC_ALL LC_COLLATE LC_CTYPE LC_MONETARY LC_NUMERIC LC_TIME
MATH
       Constants
               HUGE_VAL
SIGNAL
       Constants
               SA_NOCLDSTOP SA_NOCLDWAIT SA_NODEFER SA_ONSTACK SA_RESETHAND
               SA_RESTART SA_SIGINFO SIGABRT SIGALRM SIGCHLD SIGCONT SIGFPE
               SIGHUP SIGILL SIGINT SIGKILL SIGPIPE SIGQUIT SIGSEGV SIGSTOP
               SIGTERM SIGTSTP SIGTTIN SIGTTOU SIGUSR1 SIGUSR2 SIG_BLOCK
               SIG_DFL SIG_ERR SIG_IGN SIG_SETMASK SIG_UNBLOCK
STAT
       Constants
               S_IRGRP S_IROTH S_IRUSR S_IRWXG S_IRWXO S_IRWXU S_ISGID S_ISUID
               S_IWGRP S_IWOTH S_IWUSR S_IXGRP S_IXOTH S_IXUSR
       Macros  S_ISBLK S_ISCHR S_ISDIR S_ISFIFO S_ISREG
STDLIB
       Constants
               EXIT_FAILURE EXIT_SUCCESS MB_CUR_MAX RAND_MAX
STDIO
       Constants
               BUFSIZ EOF FILENAME_MAX L_ctermid L_cuserid L_tmpname TMP_MAX
TIME
       Constants
               CLK_TCK CLOCKS_PER_SEC
UNISTD
       Constants
               R_OK SEEK_CUR SEEK_END SEEK_SET STDIN_FILENO STDOUT_FILENO
               STDERR_FILENO W_OK X_OK
WAIT
       Constants
               WNOHANG WUNTRACED
               WNOHANG         Do not suspend the calling process until a
                               child process changes state but instead return
                               immediately.
               WUNTRACED       Catch stopped child processes.
       Macros  WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG WIFSTOPPED WSTOPSIG
               WIFEXITED       WIFEXITED(${^CHILD_ERROR_NATIVE}) returns true
                               if the child process exited normally ("exit()"
                               or by falling off the end of "main()")
               WEXITSTATUS     WEXITSTATUS(${^CHILD_ERROR_NATIVE}) returns the
                               normal exit status of the child process (only
                               meaningful if WIFEXITED(${^CHILD_ERROR_NATIVE})
                               is true)
               WIFSIGNALED     WIFSIGNALED(${^CHILD_ERROR_NATIVE}) returns
                               true if the child process terminated because of
                               a signal
               WTERMSIG        WTERMSIG(${^CHILD_ERROR_NATIVE}) returns the
                               signal the child process terminated for (only
                               meaningful if
                               WIFSIGNALED(${^CHILD_ERROR_NATIVE}) is true)
               WIFSTOPPED      WIFSTOPPED(${^CHILD_ERROR_NATIVE}) returns true
                               if the child process is currently stopped (can
                               happen only if you specified the WUNTRACED flag
                               to waitpid())
               WSTOPSIG        WSTOPSIG(${^CHILD_ERROR_NATIVE}) returns the
                               signal the child process was stopped for (only
                               meaningful if
                               WIFSTOPPED(${^CHILD_ERROR_NATIVE}) is true)

perl v5.16.3                      2013-03-04                        POSIX(3pm)