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POSIX - Perl interface to IEEE Std 1003.1 |
POSIX - Perl interface to IEEE Std 1003.1
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
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. Things which are #defines in C, like EINTR or O_NDELAY, are
automatically exported into your namespace. All functions are only exported
if you ask for them explicitly. Most likely people will prefer to use the
fully-qualified function names.
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 the perlfunc manpage 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.
The POSIX module is probably the most complex Perl module supplied with the standard distribution. It incorporates autoloading, namespace games, and dynamic loading of code that's in Perl, C, or both. It's a great source of wisdom.
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.
_exit().
abort().
abs() function.
if( POSIX::access( "/", &POSIX::R_OK ) ){
print "have read permission\n";
}
Returns undef on failure.
acos().
alarm() function.
asctime().
asin().
atan().
atan2() function.
atexit() is C-specific: use END {} instead.
atof() is C-specific.
atoi() is C-specific.
atol() is C-specific.
bsearch() not supplied.
calloc() is C-specific.
ceil().
chdir() function.
chmod() function.
chown() function.
IO::Handle::clearerr() instead.
clock().
POSIX::open.
$fd = POSIX::open( "foo", &POSIX::O_RDONLY );
POSIX::close( $fd );
Returns undef on failure.
closedir() function.
cos() function.
cosh().
POSIX::open. Use POSIX::close to close the file.
$fd = POSIX::creat( "foo", 0611 );
POSIX::close( $fd );
$path = POSIX::ctermid();
ctime().
$name = POSIX::cuserid();
difftime().
div() is C-specific.
dup().
This uses file descriptors such as those obtained by calling
POSIX::open.
Returns undef on failure.
dup2().
This uses file descriptors such as those obtained by calling
POSIX::open.
Returns undef on failure.
$errno = POSIX::errno();
execl() is C-specific.
execle() is C-specific.
execlp() is C-specific.
execv() is C-specific.
execve() is C-specific.
execvp() is C-specific.
exit() function.
exp() function.
abs() function.
IO::Handle::close() instead.
fcntl() function.
IO::Handle::new_from_fd() instead.
IO::Handle::eof() instead.
IO::Handle::error() instead.
IO::Handle::flush() instead.
IO::Handle::getc() instead.
IO::Seekable::getpos() instead.
IO::Handle::gets() instead.
IO::Handle::fileno() instead.
floor().
fmod().
IO::File::open() instead.
fork() function.
POSIX::open.
The following will determine the maximum length of the longest allowable
pathname on the filesystem which holds /tmp/foo.
$fd = POSIX::open( "/tmp/foo", &POSIX::O_RDONLY );
$path_max = POSIX::fpathconf( $fd, &POSIX::_PC_PATH_MAX );
Returns undef on failure.
fprintf() is C-specific--use printf instead.
fputc() is C-specific--use print instead.
fputs() is C-specific--use print instead.
fread() is C-specific--use read instead.
free() is C-specific.
freopen() is C-specific--use open instead.
($mantissa, $exponent) = POSIX::frexp( 3.14 );
fscanf() is C-specific--use <> and regular expressions instead.
IO::Seekable::seek() instead.
IO::Seekable::setpos() instead.
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 );
IO::Seekable::tell() instead.
fwrite() is C-specific--use print instead.
getc() function.
getgrgid() function.
getgrnam() function.
getlogin() function.
getpgrp() function.
getppid() function.
getpwnam() function.
getpwuid() function.
gmtime() function.
kill() function.
labs() is C-specific, use abs instead.
ldexp().
ldiv() is C-specific, use / and int instead.
link() function.
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() function.
log() function.
log10().
longjmp() is C-specific: use die instead.
POSIX::open.
$fd = POSIX::open( "foo", &POSIX::O_RDONLY );
$off_t = POSIX::lseek( $fd, 0, &POSIX::SEEK_SET );
Returns undef on failure.
malloc() is C-specific.
mblen().
mbstowcs().
mbtowc().
memchr() is C-specific, use index() instead.
memcmp() is C-specific, use eq instead.
memcpy() is C-specific, use = instead.
memmove() is C-specific, use = instead.
memset() is C-specific, use x instead.
mkdir() function.
mkfifo().
Returns undef on failure.
Synopsis:
mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = 0)
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.
($fractional, $integral) = POSIX::modf( 3.14 );
nice().
Returns undef on failure.
offsetof() is C-specific.
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.
$dir = POSIX::opendir( "/tmp" );
@files = POSIX::readdir( $dir );
POSIX::closedir( $dir );
Returns undef on failure.
The following will determine the maximum length of the longest allowable
pathname on the filesystem which holds /tmp.
$path_max = POSIX::pathconf( "/tmp", &POSIX::_PC_PATH_MAX );
Returns undef on failure.
pause().
Returns undef on failure.
perror().
POSIX::open.
($fd0, $fd1) = POSIX::pipe();
POSIX::write( $fd0, "hello", 5 );
POSIX::read( $fd1, $buf, 5 );
$ret = POSIX::pow( $x, $exponent );
putc() is C-specific--use print instead.
putchar() is C-specific--use print instead.
puts() is C-specific--use print instead.
qsort() is C-specific, use sort instead.
rand() is non-portable, use Perl's rand instead.
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.
readdir() function.
realloc() is C-specific.
unlink() function.
rename() function.
rewinddir() function.
rmdir() function.
scanf() is C-specific--use <> and regular expressions instead.
setjmp() is C-specific: use eval {} instead.
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 the perllocale manpage.
$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 the perllocale manpage for how to find out which locales are available in your system.
$loc = setlocale( LC_ALL, "es_AR.ISO8859-1" );
setpgid().
Returns undef on failure.
setsid().
POSIX::SigAction objects for the
action and oldaction arguments. Consult your system's sigaction
manpage for details.
Synopsis:
sigaction(sig, action, oldaction = 0)
Returns undef on failure.
siglongjmp() is C-specific: use die instead.
POSIX::SigSet
objects for the sigset argument. Consult your system's sigpending
manpage for details.
Synopsis:
sigpending(sigset)
Returns undef on failure.
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.
sigsetjmp() is C-specific: use eval {} instead.
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() function.
sinh().
sleep() function.
sprintf() function.
sqrt() function.
sscanf() is C-specific--use regular expressions instead.
stat() function.
strcat() is C-specific, use .= instead.
strchr() is C-specific, use index() instead.
strcmp() is C-specific, use eq instead.
strcoll().
strcpy() is C-specific, use = instead.
strcspn() is C-specific, use regular expressions instead.
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. These are aAbBcdHIjmMpSUwWxXyYZ%.
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() is C-specific, use length instead.
strncat() is C-specific, use .= instead.
strncmp() is C-specific, use eq instead.
strncpy() is C-specific, use = instead.
stroul() is C-specific.
strpbrk() is C-specific.
strrchr() is C-specific, use rindex() instead.
strspn() is C-specific.
index() function.
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() is C-specific.
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.
Note: Some vendors supply strtod and strtol but not strtoul. Other vendors that do suply strtoul parse ``-1'' as a valid value.
$dst = POSIX::strxfrm( $src );
The following will get the machine's clock speed.
$clock_ticks = POSIX::sysconf( &POSIX::_SC_CLK_TCK );
Returns undef on failure.
system() function.
tan().
tanh().
tcdrain().
Returns undef on failure.
tcflow().
Returns undef on failure.
tcflush().
Returns undef on failure.
tcgetpgrp().
tcsendbreak().
Returns undef on failure.
tcsetpgrp().
Returns undef on failure.
time() function.
times() function returns elapsed realtime since some point in the past
(such as system startup), user and system times for this process, and user
and system times used by child processes. All times are returned in clock
ticks.
($realtime, $user, $system, $cuser, $csystem) = POSIX::times();
Note: Perl's builtin times() function returns four values, measured in
seconds.
IO::File::new_tmpfile() instead.
$tmpfile = POSIX::tmpnam();
lc() function.
uc() function.
ttyname().
tzname variable.
POSIX::tzset();
($std, $dst) = POSIX::tzname();
tzset().
umask() function.
($sysname, $nodename, $release, $version, $machine ) = POSIX::uname();
IO::Handle::ungetc() instead.
unlink() function.
utime() function.
vfprintf() is C-specific.
vprintf() is C-specific.
vsprintf() is C-specific.
wait() function.
waitpid() function.
$pid = POSIX::waitpid( -1, &POSIX::WNOHANG );
print "status = ", ($? / 256), "\n";
wcstombs().
wctomb().
POSIX::open.
$fd = POSIX::open( "foo", &POSIX::O_WRONLY );
$buf = "hello";
$bytes = POSIX::write( $b, $buf, 5 );
Returns undef on failure.
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 fully-qualified name of a sub
which is a signal-handler. 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( 'main::handler', $sigset, &POSIX::SA_NOCLDSTOP );
This POSIX::SigAction object should be used with the POSIX::sigaction()
function.
Create an empty set.
$sigset = POSIX::SigSet->new;
Create a set with SIGUSR1.
$sigset = POSIX::SigSet->new( &POSIX::SIGUSR1 );
$sigset->addset( &POSIX::SIGUSR2 );
Returns undef on failure.
$sigset->delset( &POSIX::SIGUSR2 );
Returns undef on failure.
$sigset->emptyset();
Returns undef on failure.
$sigset->fillset();
Returns undef on failure.
if( $sigset->ismember( &POSIX::SIGUSR1 ) ){
print "contains SIGUSR1\n";
}
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;
Obtain the attributes for stdin.
$termios->getattr()
Obtain the attributes for stdout.
$termios->getattr( 1 )
Returns undef on failure.
$c_cc[1] = $termios->getcc(1);
$c_cflag = $termios->getcflag;
$c_iflag = $termios->getiflag;
$ispeed = $termios->getispeed;
$c_lflag = $termios->getlflag;
$c_oflag = $termios->getoflag;
$ospeed = $termios->getospeed;
Set attributes immediately for stdout.
$termios->setattr( 1, &POSIX::TCSANOW );
Returns undef on failure.
$termios->setcc( &POSIX::VEOF, 1 );
$termios->setcflag( $c_cflag | &POSIX::CLOCAL );
$termios->setiflag( $c_iflag | &POSIX::BRKINT );
$termios->setispeed( &POSIX::B9600 );
Returns undef on failure.
$termios->setlflag( $c_lflag | &POSIX::ECHO );
$termios->setoflag( $c_oflag | &POSIX::OPOST );
$termios->setospeed( &POSIX::B9600 );
Returns undef on failure.
This document generated by ./mkposixman.PL version 19960129.
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POSIX - Perl interface to IEEE Std 1003.1 |