#!/bin/bash

# Convert man pages to PDF and open them in the default PDF viewer.
# PDFs are cached when created.
# By Tom Harrington, tph at atomicbird dot com, 16 March 2005

# Directory to save cached PDFs in 
# (if you don't want long-term caching, you could use /tmp/).
CACHEDIR=~/Library/Caches

# Command to read PS from stdin and write PDF to an output file.
PS2PDF_CMD="/usr/bin/pstopdf -i -o"
# Command to open the resulting PDF once it's created.
OPEN_CMD="/usr/bin/open"
# Path to "man", which is expected to take the -w, -S, and -t args.
MAN_CMD="/usr/bin/man"

CACHEDIR="$CACHEDIR/manpdf"
if [ ! -e $CACHEDIR ]; then
	mkdir -p $CACHEDIR
fi

if [ $# -eq 1 ]
then
	MANSECT=""
	MANARG=$1
elif [ $# -eq 2 ]
then
	MANSECT=$1
	MANARG=$2
else
	echo "Usage: " `basename $0` "[section] name"
	exit
fi

if [ "$MANSECT" != "" ]; then
	MANSECTARG="-S $MANSECT"
fi

# Look for the command's man page.
MANFILE=`$MAN_CMD $MANSECTARG -w $MANARG 2>/dev/null`
if [ -z $MANFILE ]; then
	echo No manual entry for $MANARG
	exit
fi
# OK, got the man page.  Now get the name for the corresponding
# PDF.  The goal here is to organize cached PDFs in CACHEDIR
# according to man-page section, similar to the way /usr/share/man
# is organized into "man1", "man3", etc.
echo file: $MANFILE
MANSECT=`echo "$MANFILE" | sed 's/.*\.\([0-9]\).*/\1/'`
MANPDF=$CACHEDIR/pdf$MANSECT/$MANARG.$MANSECT.pdf
FINALDIR=`dirname $MANPDF`
echo PDF: $MANPDF
# Create the PDF if it's not in the cache dir or if the cached version is obsolete.
CREATEPDF=0
if [ ! -e $MANPDF ]; then
	echo Generating man page...
	CREATEPDF=1
else
	if [ $MANFILE -nt $MANPDF ]; then
		echo Man page newer than PDF, regenerating...
		CREATEPDF=1
	fi
fi

if [ $CREATEPDF -eq 1 ]; then
	mkdir -p $FINALDIR
	$MAN_CMD $MANSECTARG -t $MANARG | $PS2PDF_CMD $MANPDF
else
	echo Reading man page from cache...
fi
# Now open the PDF.
$OPEN_CMD $MANPDF