for foreach These flow-control keywords are documented in Compound Statements in perlsyn.

flock FILEHANDLE,OPERATION Calls flock(2), or an emulation of it, on FILEHANDLE. Returns true for success, false on failure. Produces a fatal error if used on a machine that doesn't implement flock(2), fcntl(2) locking, or lockf(3). flock is Perl's portable file-locking interface, although it locks entire files only, not records. Two potentially non-obvious but traditional flock semantics are that it waits indefinitely until the lock is granted, and that its locks are merely advisory. Such disc

Floating-point Arithmetic While use integer provides integer-only arithmetic, there is no analogous mechanism to provide automatic rounding or truncation to a certain number of decimal places. For rounding to a certain number of digits, sprintf() or printf() is usually the easiest route. See perlfaq4. Floating-point numbers are only approximations to what a mathematician would call real numbers. There are infinitely more reals than floats, so some corners must be cut. For example: printf "%.20g

NAME SYNOPSIS DESCRIPTION EXPORTABLE VARIABLES KNOWN ISSUES AUTHORS COPYRIGHT NAME FindBin - Locate directory of original perl script SYNOPSIS use FindBin; use lib "$FindBin::Bin/../lib"; or use FindBin qw($Bin); use lib "$Bin/../lib"; DESCRIPTION Locates the full path to the script bin directory to allow the use of paths relative to the bin directory. This allows a user to setup a directory tree for some software with directories <root>/bin and <root>/lib , and then the above

NAME SYNOPSIS DESCRIPTION*use Filter::Util::Call* *import()* *filter_add()* *filter() and anonymous sub* EXAMPLESExample 1: A simple filter. Example 2: Using the context Example 3: Using the context within the filter Example 4: Using filter_del Filter::Simple AUTHOR DATE LICENSE NAME Filter::Util::Call - Perl Source Filter Utility Module SYNOPSIS use Filter::Util::Call ; DESCRIPTION This module provides you with the framework to write Source Filters in Perl. An alternate interface to Fil

NAME SYNOPSIS DESCRIPTIONThe Problem A Solution Disabling or changing behaviour All-in-one interface Filtering only specific components of source code Filtering only the code parts of source code Using Filter::Simple with an explicit import subroutine Using Filter::Simple and Exporter together How it works AUTHOR CONTACT COPYRIGHT AND LICENSE NAME Filter::Simple - Simplified source filtering SYNOPSIS # in MyFilter.pm: package MyFilter; use Filter::Simple; FILTER { ... };

NAME SYNOPSIS DESCRIPTIONConsider this carefully The "access" sub-pragma Limitation with regard to _ NAME filetest - Perl pragma to control the filetest permission operators SYNOPSIS $can_perhaps_read = -r "file"; # use the mode bits { use filetest 'access'; # intuit harder $can_really_read = -r "file"; } $can_perhaps_read = -r "file"; # use the mode bits again DESCRIPTION This pragma tells the compiler to change the behaviour of the filetest permission operators, -r -w -x -R -W -

fileno FILEHANDLE Returns the file descriptor for a filehandle, or undefined if the filehandle is not open. If there is no real file descriptor at the OS level, as can happen with filehandles connected to memory objects via open with a reference for the third argument, -1 is returned. This is mainly useful for constructing bitmaps for select and low-level POSIX tty-handling operations. If FILEHANDLE is an expression, the value is taken as an indirect filehandle, generally its name. You can use

NAME SYNOPSIS DESCRIPTION SEE ALSO NAME FileHandle - supply object methods for filehandles SYNOPSIS use FileHandle; $fh = FileHandle->new; if ($fh->open("< file")) { print <$fh>; $fh->close; } $fh = FileHandle->new("> FOO"); if (defined $fh) { print $fh "bar\n"; $fh->close; } $fh = FileHandle->new("file", "r"); if (defined $fh) { print <$fh>; undef $fh; # automatically closes the file } $fh = FileHandle->new("file", O_WR

NAME SYNOPSIS DESCRIPTION CAVEATS BUGS NAME FileCache - keep more files open than the system permits SYNOPSIS no strict 'refs'; use FileCache; # or use FileCache maxopen => 16; cacheout $mode, $path; # or cacheout $path; print $path @data; $fh = cacheout $mode, $path; # or $fh = cacheout $path; print $fh @data; DESCRIPTION The cacheout function will make sure that there's a filehandle open for reading or writing available as the pathname you give it. It automatically closes and re-open