POSIX(3p) Perl Programmers Reference Guide POSIX(3p)NAMEPOSIX - Perl interface to IEEE Std 1003.1
SYNOPSIS
use POSIX;
use POSIXqw(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 iden-
tifiers 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 func-
tion, 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").
This document gives a condensed list of the features avail-
able 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.
NOTE
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.
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 sug-
gest using the Perl equivalent should one exist. For
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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 suc-
cessfully 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()" func-
tion, 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 argu-
ment. See also Math::Trig.
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alarm This is identical to Perl's builtin "alarm()" func-
tion, 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. The $wday, $yday,
and $isdst default to zero (and the first two are
usually ignored anyway).
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 argu-
ment. See also Math::Trig.
atan2 This is identical to Perl's builtin "atan2()" func-
tion, 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.
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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()" func-
tion, allowing one to change the working (default)
directory, see "chdir" in perlfunc.
chmod This is identical to Perl's builtin "chmod()" func-
tion, allowing one to change file and directory per-
missions, see "chmod" in perlfunc.
chown This is identical to Perl's builtin "chown()" func-
tion, allowing one to change file and directory own-
ers 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()" func-
tion, 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
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returning the hyperbolic cosine of its numeric argu-
ment. 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 termi-
nal.
$path = POSIX::ctermid();
ctime This is identical to the C function "ctime()" and
equivalent to "asctime(localtime(...))", see "asc-
time" and "localtime".
cuserid Get the login name of the owner of the current pro-
cess.
$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.
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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()" func-
tion for exiting the program, see "exit" in perl-
func.
exp This is identical to Perl's builtin "exp()" function
for returning the exponent (e-based) of the numeri-
cal 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()" func-
tion, 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
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"seek" in L.
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 magni-
tude of $y.
fopen Use method "IO::File::open()" instead, or see "open"
in perlfunc.
fork This is identical to Perl's builtin "fork()" func-
tion 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( $fd, &POSIX::_PC_PATH_MAX );
Returns "undef" on failure.
fprintf fprintf() is C-specific, see "printf" in perlfunc
instead.
fputc fputc() is C-specific, see "print" in perlfunc
instead.
fputs fputs() is C-specific, see "print" in perlfunc
instead.
fread fread() is C-specific, see "read" in perlfunc
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instead.
free free() is C-specific. Perl does memory management
transparently.
freopen freopen() is C-specific, see "open" in perlfunc
instead.
frexp Return the mantissa and exponent of a floating-point
number.
($mantissa, $exponent) = POSIX::frexp( 1.234e56 );
fscanf fscanf() is C-specific, use <> and regular expres-
sions 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 buil-
tin "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()" func-
tion, 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 vari-
able. The same information is available through the
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%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 perl-
var.
getgrgid
This is identical to Perl's builtin "getgrgid()"
function for returning group entries by group iden-
tifiers, 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 identif-
iers, see "getpwuid" in perlfunc.
gets Returns one line from "STDIN", similar to <>, also
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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()" func-
tion for converting seconds since the epoch to a
date in Greenwich Mean Time, see "gmtime" in perl-
func.
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
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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
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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()" func-
tion for sending signals to processes (often to ter-
minate them), see "kill" in perlfunc.
labs (For returning absolute values of long integers.)
labs() is C-specific, see "abs" in perlfunc instead.
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()" func-
tion 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.
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$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()" func-
tion, 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".
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$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 mul-
tibyte 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 per-
lop.
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()" func-
tion for creating directories, see "mkdir" in perl-
func.
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.
mktime Convert date/time info to a calendar time.
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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.
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 pro-
cess, 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 );
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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.
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POSIX(3p) Perl Programmers Reference Guide POSIX(3p)
$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 "read-
dir" in perlfunc.
realloc realloc() is C-specific. Perl does memory manage-
ment transparently.
remove This is identical to Perl's builtin "unlink()" func-
tion for removing files, see "unlink" in perlfunc.
rename This is identical to Perl's builtin "rename()" func-
tion for renaming files, see "rename" in perlfunc.
rewind Seeks to the beginning of the file.
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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()" func-
tion for removing (empty) directories, see "rmdir"
in perlfunc.
scanf scanf() is C-specific, use <> and regular expres-
sions 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 $) variable,
see "$GID" 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 follow-
ing 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 setlo-
cale(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 availabil-
ity of locales depends on your operating system.
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Please consult perllocale for how to find out which
locales are available in your system.
$loc = setlocale( LC_ALL, "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 pro-
cess.
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. Consult your system's
"sigaction" manpage for details.
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.
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" argu-
ment. Consult your system's "sigpending" manpage
for details.
Synopsis:
sigpending(sigset)
Returns "undef" on failure.
sigprocmask
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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.
sigsetjmp
"sigsetjmp()" is C-specific: use "eval {}" instead,
see "eval" in perlfunc.
sigsuspend
Install a signal mask and suspend process until sig-
nal 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 argu-
ment. 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 sig-
nificant 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()" func-
tion for returning a string that has the arguments
formatted as requested, see "sprintf" in perlfunc.
sqrt This is identical to Perl's builtin "sqrt()" func-
tion. for returning the square root of the numerical
argument, see "sqrt" in perlfunc.
srand Give a seed the pseudorandom number generator, see
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"srand" in perlfunc.
sscanf sscanf() is C-specific, use regular expressions
instead, see perlre.
stat This is identical to Perl's builtin "stat()" func-
tion for returning information about files and
directories.
strcat strcat() is C-specific, use ".=" instead, see per-
lop.
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
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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 per-
lop.
strncmp strncmp() is C-specific, use "eq" instead, see per-
lop.
strncpy strncpy() is C-specific, use "=" instead, see per-
lop.
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()" func-
tion, 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 sys-
tems set $! ($ERRNO) to indicate a translation
error, so clear $! before calling strtod. However,
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non-POSIX systems may not check for overflow, and
therefore will never set $!.
strtod should respect any POSIXsetlocale() set-
tings.
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 POSIXsetlocale() set-
tings.
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 $! can be used to check
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for valid input:
if (($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 tran-
sparently, see perllocale.
sysconf Retrieves values of system configurable variables.
The following will get the machine's clock speed.
$clock_ticks = POSIX::sysconf( &POSIX::_SC_CLK_TCK );
Returns "undef" on failure.
system This is identical to Perl's builtin "system()" func-
tion, see "system" in perlfunc.
tan This is identical to the C function "tan()", return-
ing the tangent of the numerical argument. See also
Math::Trig.
tanh This is identical to the C function "tanh()",
returning the hyperbolic tangent of the numerical
argument. See also Math::Trig.
tcdrain This is similar to the C function "tcdrain()" for
draining the output queue of its argument stream.
Returns "undef" on failure.
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tcflow This is similar to the C function "tcflow()" for
controlling the flow of its argument stream.
Returns "undef" on failure.
tcflush This is similar to the C function "tcflush()" for
flushing the I/O buffers of its argument stream.
Returns "undef" on failure.
tcgetpgrp
This is identical to the C function "tcgetpgrp()"
for returning the process group identifier of the
foreground process group of the controlling termi-
nal.
tcsendbreak
This is similar to the C function "tcsendbreak()"
for sending a break on its argument stream.
Returns "undef" on failure.
tcsetpgrp
This is similar to the C function "tcsetpgrp()" for
setting the process group identifier of the fore-
ground process group of the controlling terminal.
Returns "undef" on failure.
time This is identical to Perl's builtin "time()" func-
tion for returning the number of seconds since the
epoch (whatever it is for the system), see "time" in
perlfunc.
times The times() function returns elapsed realtime since
some point in the past (such as system startup),
user and system times for this process, and user and
system times used by child processes. All times are
returned in clock ticks.
($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.
$tmpfile = POSIX::tmpnam();
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For security reasons, which are probably detailed in
your system's documentation for the C library
tmpnam() function, this interface should not be
used; instead see File::Temp.
tolower This is identical to the C function, except that it
can apply to a single character or to a whole
string. Consider using the "lc()" function, see
"lc" in perlfunc, or the equivalent "\L" operator
inside doublequotish strings.
toupper This is identical to the C function, except that it
can apply to a single character or to a whole
string. Consider using the "uc()" function, see
"uc" in perlfunc, or the equivalent "\U" operator
inside doublequotish strings.
ttyname This is identical to the C function "ttyname()" for
returning the name of the current terminal.
tzname Retrieves the time conversion information from the
"tzname" variable.
POSIX::tzset();
($std, $dst) = POSIX::tzname();
tzset This is identical to the C function "tzset()" for
setting the current timezone based on the environ-
ment variable "TZ", to be used by "ctime()", "local-
time()", "mktime()", and "strftime()" functions.
umask This is identical to Perl's builtin "umask()" func-
tion for setting (and querying) the file creation
permission mask, see "umask" in perlfunc.
uname Get name of current operating system.
($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 iden-
tifier. Maybe.
ungetc Use method "IO::Handle::ungetc()" instead.
unlink This is identical to Perl's builtin "unlink()"
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function for removing files, see "unlink" in perl-
func.
utime This is identical to Perl's builtin "utime()" func-
tion 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()" func-
tion, 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 mul-
tibyte 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( $b, $buf, 5 );
Returns "undef" on failure.
See also "syswrite" in perlfunc.
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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 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 con-
tains 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 is intended for use
with the "POSIX::sigaction()" function.
handler
mask
flags accessor functions to get/set the values of a SigAc-
tion 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 informa-
tion 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::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;
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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.
$termios = POSIX::Termios->new;
getattr Get terminal control attributes.
Obtain the attributes for stdin.
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$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.
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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
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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
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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
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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 WIFS-
TOPPED WSTOPSIG
WIFEXITED WIFEXITED($?) returns true if the
child process exited normally
("exit()" or by falling off the end
of "main()")
WEXITSTATUS WEXITSTATUS($?) returns the normal
exit status of the child process
(only meaningful if WIFEXITED($?) is
true)
WIFSIGNALED WIFSIGNALED($?) returns true if the
child process terminated because of
a signal
WTERMSIG WTERMSIG($?) returns the signal the
child process terminated for (only
meaningful if WIFSIGNALED($?) is
true)
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WIFSTOPPED WIFSTOPPED($?) returns true if the
child process is currently stopped
(can happen only if you specified
the WUNTRACED flag to waitpid())
WSTOPSIG WSTOPSIG($?) returns the signal the
child process was stopped for (only
meaningful if WIFSTOPPED($?) is
true)
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