#!/bin/ksh
# @(#) tarz.ksh 2.0 96/06/06
# 92/10/09 john h. dubois iii (john@armory.com)
# 93/04/15 Added H option.  Fixed f option.
# 94/04/04 Added q option.
# 95/07/02 Pass . to tar instead of expanding *
# 96/01/15 Allow use of various compression utilities, read rcfile,
#          added t option, pass assorted other options to compressor.
# 96/01/21 Use rcfile in UHOME also.
# 96/06/06 Ignore chars in $COPTS that do not apply to the compressor in use.
#          Added d option.

name=${0##*/}
cOpts=H0123456789
Usage="Usage: $name [-cdfghpqvt] [-$cOpts] dirname ..."
test=false
Debug=false	# not currently used for anything
compress=compress
set -A VFlags -- -v -v
set -A Comps -- compress gzip pack
set -A Exts -- .Z .gz .z
set -A oFlags -- H 0123456789	# optional flags
typeset -i nComp=${#Comps[*]}
rcFile=.tarzrc

COPTS=
QUIET=0
FORCE=0
COMP=compress
# Source these before processing opts so assignments can be overridden.
[ -f "$UHOME/$rcFile" -a -r "$UHOME/$rcFile" ] && . "$UHOME/$rcFile"
[ -f "$HOME/$rcFile" -a -r "$HOME/$rcFile" ] && . "$HOME/$rcFile"

while getopts :cdfhvpqgtx$cOpts opt; do
    case $opt in
    h) echo \
"$name: archive a directory.
$Usage
The contents of each dirname are tarred and compressed into an archive in the
current directory with the name dirname.tar.Z.  Pathnames in the archives
are relative to dirname.  
Some options can be set in a configuration file named \"$rcFile\", which may
be in the invoking user's home directory or in the directory specified by the
environment variable UHOME (if both exist, assignments in the former take
precedence).  In this file, values are assigned to variables in shell style,
e.g. \"varname=value\".  Options given in the configuration files are
overridden by those given on the command line.  Variable names are given in
parentheses following option descriptions.
Options:
-h: Print this help.
-p: Use 'pack' to compress.   In the configuration file, put: COMP=pack
-g: Use 'gzip' to compress.   In the configuration file, put: COMP=gzip
-c: Use 'compress' to compress.   This is the default.
-n: Check for dirname.tar and compressed dirname.tar before writing output,
    and abort if either exists.  This is the default.
-f: Force writing of output even if dirname.tar or compressed dirname.tar
    exists.  In the configuration file, put: FORCE=1
-q: Be quiet; do not verbose flag to compressor or list output file.  In the
    configuration file, put: QUIET=1
-t: Tell what command would be run, but do not execute it.
-v: Be verbose; give verbose flag to compressor (if it has one), and list
    output file after archiving is completed.  This is the default.
To set any of the following options in the configuration file, use:
COPTS=options.  If any of these options are given on the command line, those in
the configuration file are ignored.  If COPTS is used in the configuration
file, any options that do not apply to the compressor in use are ignored.
-d: Dummy option to disable use of any value assigned to COPTS in config file.
-H: Make 'compress' do better compression.
-[0-9]: Set the compression level for 'gzip'."
	exit 0
	;;
    f)  FORCE=1;;
    n)  FORCE=0;;
    c)  COMP=compress;;
    d)  COPTS=;;
    g)  COMP=gzip;;
    p)  COMP=pack;;
    q)	QUIET=1;;
    v)	QUIET=0;;
    t)	test=true;;
    x)  Debug=true;;
    [$cOpts]) cOptions="$cOptions$opt";;
    +?)
	print -u2 "$name: options should not be preceded by a '+'."
	exit 1
	;;
    :) 
	print -r -u2 -- \
	"$name: Option '$OPTARG' requires a value.  Use -h for help."
	exit 1
	;;
    ?) 
	print -u2 "$name: $OPTARG: bad option.  Use -h for help."
	exit 1
	;;
    esac
done

[ "$QUIET" = 0 ] && Quiet=false || Quiet=true
[ "$FORCE" = 0 ] && Check=true || Check=false

typeset -i i=0
while [ i -lt nComp ]; do
    [ "$COMP" = "${Comps[i]}" ] && break
    let i+=1
done
if [ i -ge nComp ]; then
    print -u2 "Unknown compression type: $COMP.  Aborting."
    exit 1
fi
vflag=${VFlags[i]}
Ext=${Exts[i]}
$Quiet && vflag= || vflag=${VFlags[i]}

# Usage: SplitStr <string>
# Each character in <string> is put in a separate element in SplitStr_ret[],
# starting with 0.
# If <string> has more characters than the maximum number of elements in an
# array (1024), 1 is returned.  Otherwise 0 is returned.
function SplitStr {
    typeset s=$1
    typeset -i i=0
    unset SplitStr_ret[*]
    [ ${#s} -gt 1024 ] && return 1
    while [ -n "$s" ]; do
	ns=${s#?}
	SplitStr_ret[i]=${s%$ns}
	s=$ns
	let i+=1
    done
    return 0
}

# Usage: commonStr s1 s2
# Sets commonStr_ret to a string consisting of s1 with all of its characters
# that are not in s2 removed.
function commonStr {
    typeset c

    SplitStr "$1"
    commonStr_ret=
    for c in "${SplitStr_ret[@]}"; do
	# Use case instead of [[]] to avoid need to eval pattern comparison
	case "$c" in
	[$2]) commonStr_ret="$commonStr_ret$c"
	esac
    done
}

oFlagList=${oFlags[i]}
if [ -z "$cOptions" ]; then
    commonStr "$COPTS" "$oFlagList"
    cOptions=$commonStr_ret
fi
[ -n "$cOptions" ] && cOptions="-$cOptions"

# remove args that were options
let OPTIND=OPTIND-1
shift $OPTIND

if [ $# -lt 1 ]; then
    print -u2 "$Usage\nUse -h for help."
    exit
fi

OWD=$PWD

for dirname; do
    cd -- "$OWD"
    archname="${dirname##*/}.tar"
    if $Check; then
	if [ -f "$archname" ]; then
	    print -u2 -- \
	"$archname: file exists.  Use the -f option to overwrite.  Skipping."
	    continue
	fi
	if [ -f "$archname$Ext" ]; then
	    print -u2 -- "$archname$Ext: file exists.  Skipping."
	    continue
	fi
    fi
    if cd -- "$dirname"; then :; else
	print -u2 -- "Could not cd to '$dirname'.  Not processed."
	continue
    fi
    if $test; then
	print -- "tar cf - . | $COMP $vflag $cOptions > $OWD/$archname$Ext"
    else
	tar cf - . | $COMP $vflag $cOptions > "$OWD/$archname$Ext"
	$Quiet || l -- "$OWD/$archname$Ext"
    fi
done