5 File not found. $ lze67yLZ7 x? =head1 NAME POSIX - Perl interface to IEEE Std 1003.1 =head1 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 =head1 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. 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 L for functions which are noted as being identical or almost 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. =head1 CAVEATS I (with a handful of exceptions). This is an unfortunate backwards compatibility feature and its use is B>. You should either prevent the exporting (by saying S>, as usual) and then use fully qualified names (e.g. C), or give an explicit import list. If you do neither and opt for the default (as in S>), you will import I of symbols into your namespace. 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 C call will elicit the message "C". 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 C, or the semantics of the errno values set by C 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 C macro after all. This could be construed to be a bug. =head1 FUNCTIONS =over 8 =item C<_exit> This is identical to the C function C<_exit()>. It exits the program immediately which means among other things buffered I/O is B flushed. Note that when using threads and in Linux this is B 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. =item C This is identical to the C function C. It terminates the process with a C signal unless caught by a signal handler or if the handler does not return normally (it e.g. does a C). =item C This is identical to Perl's builtin C function, returning the absolute value of its numerical argument (except that C must be provided an explicit value (rather than relying on an implicit C<$_>): $absolute_value = POSIX::abs(42); # good $absolute_value = POSIX::abs(); # throws exception =item C Determines the accessibility of a file. if( POSIX::access( "/", &POSIX::R_OK ) ){ print "have read permission\n"; } Returns C on failure. Note: do not use C for security purposes. Between the C call and the operation you are preparing for the permissions might change: a classic I. =item C T