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<HTML><HEAD><TITLE>Recipe 8.19. Program: tctee (Perl Cookbook)</TITLE><METANAME="DC.title"CONTENT="Perl Cookbook"><METANAME="DC.creator"CONTENT="Tom Christiansen & Nathan Torkington"><METANAME="DC.publisher"CONTENT="O'Reilly & Associates, Inc."><METANAME="DC.date"CONTENT="1999-07-02T01:38:56Z"><METANAME="DC.type"CONTENT="Text.Monograph"><METANAME="DC.format"CONTENT="text/html"SCHEME="MIME"><METANAME="DC.source"CONTENT="1-56592-243-3"SCHEME="ISBN"><METANAME="DC.language"CONTENT="en-US"><METANAME="generator"CONTENT="Jade 1.1/O'Reilly DocBook 3.0 to HTML 4.0"><LINKREV="made"HREF="mailto:online-books@oreilly.com"TITLE="Online Books Comments"><LINKREL="up"HREF="ch08_01.htm"TITLE="8. File Contents"><LINKREL="prev"HREF="ch08_19.htm"TITLE="8.18. Program: tailwtmp"><LINKREL="next"HREF="ch08_21.htm"TITLE="8.20. Program: laston"></HEAD><BODYBGCOLOR="#FFFFFF"><img alt="Book Home" border="0" src="gifs/smbanner.gif" usemap="#banner-map" /><map name="banner-map"><area shape="rect" coords="1,-2,616,66" href="index.htm" alt="Perl Cookbook"><area shape="rect" coords="629,-11,726,25" href="jobjects/fsearch.htm" alt="Search this book" /></map><div class="navbar"><p><TABLEWIDTH="684"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="228"><ACLASS="sect1"HREF="ch08_19.htm"TITLE="8.18. Program: tailwtmp"><IMGSRC="../gifs/txtpreva.gif"ALT="Previous: 8.18. Program: tailwtmp"BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="228"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1"><ACLASS="chapter"REL="up"HREF="ch08_01.htm"TITLE="8. File Contents"></A></FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="228"><ACLASS="sect1"HREF="ch08_21.htm"TITLE="8.20. Program: laston"><IMGSRC="../gifs/txtnexta.gif"ALT="Next: 8.20. Program: laston"BORDER="0"></A></TD></TR></TABLE></DIV><DIVCLASS="sect1"><H2CLASS="sect1"><ACLASS="title"NAME="ch08-12981">8.19. Program: tctee</A></H2><PCLASS="para"><ACLASS="indexterm"NAME="ch08-idx-1000005181-0"></A><ACLASS="indexterm"NAME="ch08-idx-1000005181-1"></A>Not all systems support the classic <EMCLASS="emphasis">tee</EM> program for splitting output pipes to multiple destinations. This command sends the output from <EMCLASS="emphasis">someprog</EM> to <EMCLASS="emphasis">/tmp/output</EM> and to the mail pipe beyond.</P><PRECLASS="programlisting">% someprog | tee /tmp/output | Mail -s 'check this' user@host.org</PRE><PCLASS="para">This program helps not only users who aren't on Unix systems and don't have a regular <EMCLASS="emphasis">tee</EM>. It also helps those who are, because it offers features not found on other version of <EMCLASS="emphasis">tee</EM>.</P><PCLASS="para">The four flag arguments are <BCLASS="emphasis.bold">-i</B> to ignore interrupts, <BCLASS="emphasis.bold">-a</B> to append to output files, <BCLASS="emphasis.bold">-u</B> for unbuffered output, and <BCLASS="emphasis.bold">-n</B> to omit copying the output on to standard out.</P><PCLASS="para">Because this program uses Perl's <ACLASS="indexterm"NAME="ch08-idx-1000005224-0"></A>magic open, you can specify pipes as well as files.</P><PRECLASS="programlisting">% someprog | tctee f1 "|cat -n" f2 ">>f3"</PRE><PCLASS="para">That sends the output from <EMCLASS="emphasis">someprog</EM> to the files <EMCLASS="emphasis">f1</EM> and <EMCLASS="emphasis">f2</EM>, appends it to <EMCLASS="emphasis">f3</EM>, sends a copy to the program <EMCLASS="emphasis">cat -n</EM>, and also produces the stream on standard output.</P><PCLASS="para">The program in <ACLASS="xref"HREF="ch08_20.htm#ch08-41455"TITLE="tctee">Example 8.8</A> is one of many venerable Perl programs written nearly a decade ago that still runs perfectly well. If written from scratch now, we'd probably <CODECLASS="literal">use</CODE> <CODECLASS="literal">strict</CODE>, warnings, and ten to thirty thousand lines of modules. But if it ain't broke . . .</P><DIVCLASS="example"><H4CLASS="example"><ACLASS="title"NAME="ch08-41455">Example 8.8: tctee</A></H4><PRECLASS="programlisting">#!/usr/bin/perl# tctee - clone that groks process tees # perl3 compatible, or better.while ($ARGV[0] =~ /^-(.+)/ && (shift, ($_ = $1), 1)) { next if /^$/; s/i// && (++$ignore_ints, redo); s/a// && (++$append, redo); s/u// && (++$unbuffer, redo); s/n// && (++$nostdout, redo); die "usage tee [-aiun] [filenames] ...\n";}if ($ignore_ints) { for $sig ('INT', 'TERM', 'HUP', 'QUIT') { $SIG{$sig} = 'IGNORE'; }}$SIG{'PIPE'} = 'PLUMBER';$mode = $append ? '>>' : '>';$fh = 'FH000';unless ($nostdout) { %fh = ('STDOUT', 'standard output'); # always go to stdout }$| = 1 if $unbuffer;for (@ARGV) { if (!open($fh, (/^[^>|]/ && $mode) . $_)) { warn "$0: cannot open $_: $!\n"; # like sun's; i prefer die $status++; next; } select((select($fh), $| = 1)[0]) if $unbuffer; $fh{$fh++} = $_;}while (<STDIN>) { for $fh (keys %fh) { print $fh $_; }}for $fh (keys %fh) { next if close($fh) || !defined $fh{$fh}; warn "$0: couldnt close $fh{$fh}: $!\n"; $status++;}exit $status;sub PLUMBER { warn "$0: pipe to \"$fh{$fh}\" broke!\n"; $status++; delete $fh{$fh};}<ACLASS="indexterm"NAME="ch08-idx-1000004732-0"></A><ACLASS="indexterm"NAME="ch08-idx-1000004732-1"></A></PRE></DIV></DIV><DIVCLASS="htmlnav"><P></P><HRALIGN="LEFT"WIDTH="684"TITLE="footer"><TABLEWIDTH="684"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="228"><ACLASS="sect1"HREF="ch08_19.htm"TITLE="8.18. Program: tailwtmp"><IMGSRC="../gifs/txtpreva.gif"ALT="Previous: 8.18. 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