package VCP::Logger; =head1 NAME VCP::Logger - Update message, bug, and Log file management =head1 SYNOPSIS use VCP::Logger qw( shell_quote ); =head1 DESCRIPTION Does not throw exceptions or use the debug module, so this is safe to use with both. Load this as the very first module in your program. The log file name defaults to "vcp.log", set the environment variable VCPLOGFILE to change it. Here's how to do this in your program: BEGIN { $ENV{VCPLOGFILE} = "foo.bar" unless defined $ENV{VCPLOGFILE} || length $ENV{VCPLOGFILE}; } =cut @EXPORT_OK = qw( BUG lg lg_fh log_file_name pr program_name start_time ); @ISA = qw( Exporter ); use Exporter; use strict ; use Carp; use File::Basename qw( basename ); use constant program_name => basename $0; use constant log_file_name => defined $ENV{VCPLOGFILE} && length $ENV{VCPLOGFILE} ? $ENV{VCPLOGFILE} : "vcp.log"; my $quiet_mode = 0; =head1 FUNCTIONS =over =item lg Prints a timestamped message to the log. Adds a trailing newline if need be. The first word of the message should not be capitalized unless it's a name or acronym; this makes grepping a bit easier (same for all error messages). "lg" is "log" abbreviated so as not to conflict with Perl's builtin log(). The timestamps are in integer seconds since this module was compiled unless you have Time::HiRes install in which case they are in floating point seconds. Should not throw an exception or alter $@ in the normal course of events (does not call any routines that should do so). =cut my $start_time; ## We "gracefully" degrade to 1 second resolution if no Time::HiRes. BEGIN { eval "use Time::HiRes qw( time )" } BEGIN { $start_time = time; } { my $s1; BEGIN { $s1 = program_name . ": " } sub _msg { my $msg = join "", map defined $_ ? $_ : "(((UNDEF)))", @_; 1 while chomp $msg; $msg =~ s/^$s1//o; ## TODO: go 'round and get rid of all the vcp: prefixes join $msg, $s1, "\n"; } my $log_failure_warned; sub _lg { print LOG ( sprintf( "%f ", time - $start_time ), @_ ) or $log_failure_warned++ or warn "$! writing ", program_name, " log file ", log_file_name, "\n"; } } sub lg { _lg &_msg; } =item lg_fh Returns a reference to the log filehandle (*LOG{IO}) so you can emit to the log directly. The log is flushed after every write, so this should be quite safe. =cut sub lg_fh { *LOG{IO} } =item pr Emit a status notification to STDERR (unless in quiet mode) and log it. =cut sub pr { my $msg = &_msg; print STDERR $msg unless $quiet_mode; _lg $msg; } BEGIN { open LOG, ">>" . log_file_name or die "$!: " . log_file_name . "\n"; ## Flush the LOG every print() so that we never miss data and ## so that we can pass the log to child processes to emit STDOUT ## and STDERR to. select LOG; $| = 1; select STDOUT; ## Print a header line guaranteed to start at the beginning of a ## line. print LOG "\n", "#" x 79, "\n"; lg "started ", scalar localtime $start_time, " (", scalar gmtime $start_time, " GMT)"; } END { lg "ended"; } =item BUG Reports a bug using Carp::confess and logging the information. =cut sub BUG { print STDERR "***BUG REPORT***\n", @_, "\n"; print STDERR "Please see ", log_file_name, "\n"; print LOG "***BUG REPORT***\n", @_, "\n"; open STDOUT, ">&LOG" or warn "$! redirecting STDOUT to LOG\n"; open STDERR, ">&LOG" or warn "$! redirecting STDOUT to LOG\n"; system $^X, "-V" and warn "$! getting perl -V\n"; require Carp; eval { Carp::confess "stack trace" }; warn $@; exit 1; } =item start_time Returns the time the application started. This is a floating point number if Time::HiRes was found. =cut sub start_time() { $start_time } =back =head1 COPYRIGHT Copyright 2000, Perforce Software, Inc. All Rights Reserved. This module and the VCP package are licensed according to the terms given in the file LICENSE accompanying this distribution, a copy of which is included in L. =cut 1 ;