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a cron; in perl: Source

by belg4mit (Prior)
on Nov 17, 2001 at 05:14 UTC ( #125968=note: print w/ replies, xml ) Need Help??


in reply to a cron; in perl

#!/usr/bin/perl -w use strict; BEGIN{ $0 = "crond"; require 5; use Fcntl; use File::Basename; use File::Spec; use Getopt::Std; use POSIX (); use Symbol; #Support pre 5.6; they don't auto-vivify on open $Mail::Sendmail::VERSION = $Mail::Send::VERSION = 0; eval 'use Mail::Send'; eval 'use Mail::Sendmail' if $@ || ! $Mail::Send::VERSION; } my($pid, %EXPLODECACHE, %OPT, $VERSION); $VERSION = 0.82; #Get config/options { my @defbug; %ENV = ( CRONDAEMON=>1, #!-X CRONDEBUG =>0, #!-x CRONEMBED =>0, #!-O CRONLOG =>'/var/log/cron/', # -L CRONMAIL =>1, #!-M; extend this to MAILTO?! CRONONCE =>0, #!-1 CRONSERIAL=>0, #!-s CRONSOGGY =>0, #!-S CRONUNSAFE=>0, #!-U HOME =>'/', LOGNAME =>'', MAILTO =>'', PATH =>$ENV{PATH}, SHELL =>'/bin/sh' ); if( -r '/etc/default/cron' && open(DEFAULT, '/etc/default/cron') ){ my(%default, %verboseOPT); %verboseOPT = ( CRONDAEMON=>'X', CRONDEBUG =>'x', CRONEMBED =>'O', CRONLOG =>'L', CRONMAIL =>'M', CRONONCE =>'1', CRONSERIAL=>'s', #UPDATE: Oops forgot this. CRONSOGGY =>'S', CRONUNSAFE=>'U' ); while(<DEFAULT>){ chomp(); next if /^\s*(?:\#|$)/; if( /^\s*([^\s]*?)\s*=\s*(.*)/ ){ push(@defbug, "DEBUG2 (Setting envar $1 => $2) "); $default{uc($1)} = $2; next; } } %ENV = (%ENV, %default); foreach my $var ( grep {/^CRON/ } keys %ENV ){ $ENV{$var} = 1 if lc($ENV{$var}) eq 'yes'; $ENV{$var} = 0 if lc($ENV{$var}) eq 'no'; $OPT{$verboseOPT{$var}} = delete($ENV{$var}); } } getopts('1f:hsx:F:L:MOSUX', \%OPT); if( $OPT{h} || scalar @ARGV ){ die("Usage: $0 [-1MOSUXhs] [-F file] [-L dir] [-f file] [-x debugf +lag]\n"); } $OPT{s} = $OPT{X} ? 1 : ($OPT{s} || 0); #XXX -s could imply -U but for perhaps allowing group changing?! # multiple levels of U? 1 is all 2 is except groups? debug(@defbug) if $OPT{x} & 2 && @defbug; if( $OPT{S} ){ eval "use File::Temp ':POSIX'"; if( $@ && $OPT{O} ){ *tmpnam = *POSIX::tmpnam; } else{ #XXX set security based on $] #File::Temp->safe_level( File::Temp::HIGH() ); } } if( $OPT{x} & 1 ){ eval 'use Data::Dumper'; debug("DEBUG (%OPT = %{\n", Dumper(\%OPT), "})"); } } #Be a good little daemon { $OPT{f} = File::Spec->rel2abs($OPT{f}) if $OPT{f}; $OPT{F} = File::Spec->rel2abs($OPT{F}) if $OPT{F}; chdir(File::Spec->rootdir) || die("Couldn't chdir to ROOT directory: + $!\n"); if( $OPT{X} ){ debug("STARTED (no fork)"); } else{ unless( defined($pid = fork()) ){ die("Couldn't fork: $!\n"); } exit 0 if $pid; POSIX::setsid(); debug("STARTED (fork ok)"); open(STDIN, '<'. File::Spec->devnull) || die("Can't read from NULL device: $!\n"); open(STDOUT, '>'. File::Spec->devnull) unless $OPT{L} eq '-' || die("Can't write from NULL device: $!\n"); } } #Set us up the bomb (read configuration) my(@PJOBS, @TABOPT, %TABMTIME); LOAD: { my($crontabindex, @crontabs, @crontabpaths, @groups); $crontabindex =0; #This is to prevent memory leaks %EXPLODECACHE = @PJOBS = @TABOPT = (); unless( $OPT{U} ){ while( my @F = getgrent() ){ push @groups, [@F] }; endgrent(); } if( $OPT{f} || $OPT{F} ){ push(@crontabpaths, [0, $OPT{f}]) if $OPT{f}; #-f push(@crontabpaths, [1, $OPT{F}]) if $OPT{F}; #-F } else{ # [user(0=none, 1=6th field, 2=filename), file] @crontabpaths = ( [1, '/etc/crontab'], #System crontab [1, '/etc/cron.d'], #System crontabs [2, '/var/spool/cron'], #User crontabs [2, '/var/spool/cron/crontabs'] # " " +on Sun ); } foreach my $crontabpath ( @crontabpaths ){ stat $crontabpath->[1]; if( -d _ && opendir(CRONTABPATH, $crontabpath->[1]) ){ push(@crontabs, map([$crontabpath->[0], File::Spec->catfile($crontabpath->[ +1], $_)], grep {!/^\./} readdir(CRONTABPATH) ) ); closedir(CRONTABPATH); } elsif( -e _ ){ push(@crontabs, $crontabpath); } else{ next; } $TABMTIME{$crontabpath->[1]} = -M _; } foreach my $tab ( @crontabs ){ local %ENV = %ENV; open(TAB, $tab->[1]) || carp("WARN (Couldn't open $tab->[1]: $!)") + && next; debug("DEBUG2 (Reading '$tab->[1]')") if $OPT{x} & 2; while( <TAB> ){ local $ENV{USER}; chomp(); next if /^\s*(?:\#|$)/; if( /^\s*([^\s]*?)\s*=\s*(.*)/ ){ debug("DEBUG2 (Setting envar $1 => $2)") if $OPT{x} & 2; $ENV{uc($1)} = $2; next; } my @fields = split(/\s+/); debug("DEBUG2 (", join(',', @fields), ")") if $OPT{x} & 2; if( $tab->[0] == 1){ $ENV{USER} = splice(@fields,5,1); } elsif( $tab->[0] == 2 ){ my $user = basename($tab->[1]); next unless getpwnam($user); $ENV{USER} = $user; } $ENV{USER} ||= $OPT{U} ? 'undef' : scalar getpwuid($<); $ENV{UID} ||= $OPT{U} ? $< : scalar getpwnam($ENV{USER}) +|| $<; if( exists($ENV{MAILTO}) && ! defined($ENV{MAILTO}) ){ delete($ENV{MAILTO}); } else{ $ENV{MAILTO} ||= $ENV{USER}; } unless( $OPT{U} ){ $ENV{GID} = join(':', map($_->[2], grep($_->[3] =~ /\b$ENV{USER}\b/,@grou +ps) ) )|| [grep(lc($_->[0]) eq lc($ENV{USER}), @groups)]->[0]- +>[2]; } else{ $ENV{GID} = $(; } $ENV{LOGNAME} = $ENV{USER}; $ENV{HOME} ||= $OPT{U} ? File::Spec->rootdir : (getpwnam($ENV{US +ER}))[7]; push(@PJOBS, [splice(@fields,0,5), [$crontabindex, { GID => delete($ENV{GID}), UID => delete($ENV{UID}), HOME => delete($ENV{HOME}), USER => delete($ENV{USER}), MAILTO => delete($ENV{MAILTO}), LOGNAME => delete($ENV{LOGNAME}) +}, join(' ', @fields)]]); debug("DEBUG2 (Saving job CMD(@fields))") if $OPT{x} & 2; } close(TAB); #XXX debug statement instantiates the key, gets us an error later. +.. delete $ENV{USER}; $TABOPT[$crontabindex++] = \%ENV; } } #Create EXPLODECACHE { my %verbosetime = (SUN=>0, MON=>1, TUE=>2, WED=>3, THU=>4, FRI=>5, S +AT=>6, JAN=>1, FEB=>2, MAR=>3, APR=>4, MAY=>5, JUN=>6, J +UL=>7, AUG=>8, SEP=>9, OCT=>10,NOV=>11,DEC=>12); sub explode{ my @exploded; return $EXPLODECACHE{$_[0]} if exists $EXPLODECACHE{$_[0]}; foreach ( split(/,/, $_[0]) ){ if( m%\*/(\d+)% ){ for(my $i=0; $i<60; $i+=$1){ push(@exploded, $i); } } elsif( /-/ ){ my($i, $j, $k) = ($_ =~ m%(\d+)-(\d+)(?:/(\d+))?% ); $i = $verbosetime{uc($i)} || $i; $j = $verbosetime{uc($j)} || $j; $k ||= 1; for(; $i<=$j; $i+=$k){ push(@exploded, $i); } } else{ push(@exploded, $verbosetime{uc()} || $_); } } $EXPLODECACHE{$_[0]} = [@exploded]; } foreach my $job (@PJOBS){ do { explode($job->[$_]); } for (0..4); } } #AD INFINITUM while(1){ debug("DEBUG1 (I'm alive and checking)") if $OPT{x} & 1; my @time = localtime(time()); foreach my $job (@PJOBS){ my $pid; debug("DEBUG4 (", "($job->[0] eq '*' || $job->[0] == $time[1]) &&", "($job->[1] eq '*' || $job->[1] == $time[2]) &&", "($job->[2] eq '*' || $job->[2] == $time[3]) && (", "($job->[4] eq '*' || $job->[4] == $time[6]) ||", "($job->[3] eq '*' || $job->[3] == $time[4]) ) )") if $OPT{x +} & 4; next unless $job->[0] eq '*' || grep($_ == $time[1], @{$EXPLODECACHE{$job->[0]}} +); next unless $job->[1] eq '*' || grep($_ == $time[2], @{$EXPLODECACHE{$job->[1]}} +); next unless $job->[2] eq '*' || grep($_ == $time[3], @{$EXPLODECACHE{$job->[2]}} +); next unless ($job->[4] eq '*' || grep($_ == $time[6], @{$EXPLODECACHE{$job->[4]}} +) ) || ($job->[3] eq '*' || grep($_ == $time[4], @{$EXPLODECACHE{$job->[3]}} +) ); next if $job->[5]->[2] =~ /^#/ && ! $OPT{O}; #Save the forks! debug("DEBUG4 (Got a job)") if $OPT{x} & 4; if( $OPT{s} ){ job($job->[5]); } else{ unless( defined($pid = fork()) ){ #Really a croak but can't be fatal; since we're the grandparen +t carp("DIE (Couldn't fork: $!)"); next; } job($job->[5]) unless $pid; } } $OPT{1} && exit 0; #XXXsleep 60; #XXXdo{ $kid= waitpid(-1, POSIX::WNOHANG()); } until -1 == $kid; for(my $i=0; $i<12; $i++){ sleep 5; while( waitpid(-1, POSIX::WNOHANG()) != -1 ){} } foreach (keys %TABMTIME){ goto LOAD if $TABMTIME{$_} != (-M $_ || 0); } } sub carp{ warn(@_) if $OPT{X} && $OPT{L} ne '-'; l0g('warnings', 'CARP (', @_, ')'); } sub croak{ warn(@_) if $OPT{X} && $OPT{L} ne '-'; l0g('errors', 'CROAK (', @_, ')'); exit 0 unless $OPT{s}; } sub debug{ l0g('info', @_); } sub job{ my($FRMCHLD, $chldinput, $chldoutput, $return, $CHLDSTDIN, $TOCHLD); $return = "undef"; #Don't kill hashes in perl jobs if( $_[0]->[2] !~ /^#/ && $_[0]->[2] =~ /([^%]+)%(.*)/ ){ return croak("Embedded newlines (%) not allowed with -S") if $OPT{ +S}; $_[0]->[2] = $1; $chldinput = $2; $chldinput =~ s/(.)%/ $1 eq "\\" ? '%' : "$1\n" /eg; pipe($CHLDSTDIN=gensym(), $TOCHLD=gensym()) || croak("Couldn't create pipe: $!"); } %ENV = (%{$TABOPT[$_[0]->[0]]}, %{$_[0]->[1]}); if( $OPT{S} ){ open(STDERR, ">&STDOUT"); if( $OPT{O} && $_[0]->[2] =~ /#!perl\s+-e\s+(.*)/ ){ local $/ = undef; my $TMP = gensym(); my $tmpfile = tmpnam(); open($TMP, "+>$tmpfile"); my $oldout = select($TMP); $0 = "perl -e $1"; { local *STDOUT = $TMP; local *STDERR = $TMP; local $SIG{__WARN__} = sub{print STDERR @_}; eval($1); } select($oldout); if($@){ return croak("Failed (with $@) evaluting\n$1"); } seek($TMP,0,0); $chldoutput = join('', <$TMP>); close($TMP); unlink($tmpfile); } else{ $chldoutput = qx($_[0]->[2]); } } else{ my $pid = 0 || open($FRMCHLD=gensym(), "-|"); #XXX Michael Schwern of p5p reports former doesn;t work on VMS in +5.7.2 #|| open($FRMCHLD=gensym(), "-|", 'perl bug') ;#?! unless( defined($pid) ){ croak("Couldn't fork: $!"); return -1; } if( $pid ){ $0 = uc($0) . "($pid) "; $ENV{USER} = $_[0]->[1]->{USER}; if( defined($chldinput) ){ #close($CHLDSTDIN); #XXX gives SIGPIPE print $TOCHLD $chldinput; close($TOCHLD); } $chldoutput = join('', <$FRMCHLD>); $return = close($FRMCHLD); } else{ my $gid; if( defined($chldinput) ){ close($TOCHLD); my $fileno = fileno($CHLDSTDIN); open(STDIN, "<&$fileno"); } open(STDERR, ">&STDOUT"); unless( $< || $OPT{U} ){ $gid = $ENV{GID}; $gid =~ tr/:/ /; $gid = $gid =~ / / ? $gid : "$gid $gid"; $( = $) = $gid; $< = $> = $ENV{UID}; sub list{ my $prev = 'NaN'; return join(',', grep($_ ne $prev && (($prev) = $_), sort split($_[0], $_[1] ))); }; croak("DIE (Couldn't setregid($(, $gid): $!)") unless ($( eq $)) && list(' ', $() eq list(':', $ENV{GID}); croak("DIE (Couldn't setreuid($<, $ENV{UID}): $!") unless ($< == $>) && ($> == $ENV{UID}); } $ENV{PATH} = delete($ENV{SUPATH}) unless $< && ! exists($ENV{SUP +ATH}); if( $OPT{O} && $_[0]->[2] =~ /#!perl\s+-e\s+(.*)/ ){ $0 = "perl -e $1"; eval $1; } else{ exec($_[0]->[2]); } exit(); } } debug("CMD ($_[0]->[2])[$return]"); debug("DEBUG8 (\n", $chldoutput, ")") if $OPT{x} & 8; mail($ENV{MAILTO}, $chldoutput) if $ENV{MAILTO} && $chldoutput; if( $OPT{s} ){ $0 = "crond"; return 0; } else{ exit 0; } } sub l0g{ return unless $OPT{L}; my $log = shift(); open(LOG, $OPT{L} eq '-' ? '>-' : ">>$OPT{L}/$log" ) || return; #Can't rely on LOCK_EX being 2 for cross-platform flock(LOG, Fcntl::LOCK_EX()) unless $OPT{L} eq '-'; print LOG scalar localtime(time()), " $0\[$$\]: (", $ENV{USER}||$<," +) @_\n"; close(LOG) unless $OPT{L} eq '-'; } sub mail{ return if $OPT{M}; my @x_cron_env; foreach my $key ( keys %ENV ){ push @x_cron_env, "<$key=$ENV{$key}>"; } if( $Mail::Send::VERSION ){ my($msg, $fh); $msg = new Mail::Send; $msg->to($_[0]); $msg->subject($0); $msg->set('X-Cron-Env', @x_cron_env); $fh = $msg->open; print $fh $_[1]; $fh->close; } elsif( $Mail::Sendmail::VERSION ){ my(%mail, $host); #XXXbe smarter later... $host = $mail{smtp} = 'localhost'; %mail = ( %mail, From => "$ENV{USER}\@$host", To => $_[0] =~ /@/ ? $_[0] : "$_[0]\@$host", Subject => $0, Message => $_[1], "X-Cron-Env" => join(',', @x_cron_env), ); #Damn strict vars, maybe this gets optimized out $Mail::Sendmail::mailcfg = $Mail::Sendmail::mailcfg; $Mail::Sendmail::mailcfg{mime} = 0; Mail::Sendmail::sendmail(%mail); } else{ open(MAIL, "|/bin/mail -s \"@{[quotemeta($0)]}\" $_[0]") || carp("WARN (Couldn't mail $_[0])(\n$_[1]\n)"); print MAIL join("\n", map("X-Cron-Env: $_", @x_cron_env)), "\n"; print MAIL $_[1]; close(MAIL); } }


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