:
##########################################################################
# Title      :	replace - replace older with newer files
# Author     :	Heiner Steven <heiner.steven@odn.de>
# Date       :	1994-01-25
# Requires   :	
# Category   :	File Utilities
# SCCS-Id.   :	@(#) replace	2.1 14/05/01
##########################################################################
# Description
#
##########################################################################

PN=`basename "$0"`			# Program mname
VER='2.1'

usage () {
    echo >&2 "$PN - replace older files with newer ones, $VER (stv '95)
usage: $PN [-av] file [file ...] targetdir
    -a: (add)     copy files not contained in targetdir
    -F: (force)   ignore errors (e.g. non-existing files).
                  Otherwise $PN will abort execution at first error.
    -v: (verbose) print diagnostics
    
Copied files get the modification timestamp of the source files,
not the current time."
    exit 1
}

msg () {
    [ "$Verbose" = no ] && return 0

    for i
    do echo "$PN: $i" >&2
    done
}

fatal () { Verbose=true; msg "$@"; exit 1; }

# newer - Test if file1 is newer (or same age) as file2
newer () {
    [ $# -ne 2 ] && return 1

    # Uncomment the following code block if you have a newer
    # shell like ksh(1) or bash(1) supporting the -nt (newer
    # time) test operator
    #if [ "$1" -nt "$2" ]
    #then return 0
    #else return 1
    #fi

    # If both files have the same date, some systems return the
    # first file name given to "ls"; some return the second
    Newest=`ls -t "$2" "$1" | head -1`
    [ -z "$Newest" ] && return 2	# error
    if [ "$Newest" = "$1" ]
    then return 0
    else return 1
    fi
}

Verbose=false				# parameter -v
Add=false				# copy new files (true/false)
ForceRun=false
while [ $# -gt 1 ]
do
    case "$1" in
	-a) Add=true ;;
	-F) ForceRun=true ;;
	-v) Verbose=true ;;
	-*) usage ;;
	*)  break ;;
    esac
    shift
done

if [ $# -lt 2 ]
then usage
else
    # Get last command line argument, the destination directory.
    TargetDir=
    for TargetDir
    do :	# We are just interested in the very last positional argument
    done
    [ -d "$TargetDir" ] || fatal "ERROR: directory not found: $TargetDir"
fi

error=0
copycount=0
while [ $# -gt 1 ]	# Omit last argument (target directory)
do
    Source=$1; shift
    if [ -f "$Source" ]
    then
	Name=`basename "$Source"`
	Copy=false
	if [ -f  "$TargetDir/$Name" ]
	then				# File exists in target directory
	    newer "$Source" "$TargetDir/$Name" && Copy=true
	else
	    if [ "$Add" = "true" ]
	    then Copy=true
	    else msg "not in target directory: '$Name'; ignored"
	    fi
	fi

	if [ "$Copy" = "true" ]
	then
	    msg " replacing $TargetDir/$Name"

	    # Copy file keeping the source file's time stamp.
	    # Note that superfluous copying can happen in the
	    # following case:
	    #	 o  The file sytem keeps the modification time
	    #	    stamp in a resolution higher than 1 second
	    #	    (e.g. btrfs).
	    #	 o  The "cp -p" implementation does truncate the
	    #	 file modification timestamp of the destination
	    #	 file to complete seconds (e.g. GNU cp(1) 8.21)

	    if cp -p "$Source" "$TargetDir/$Name"
	    then
		copycount=`expr "$copycount" + 1`
	    else
		error=1
		# cp(1) already printed an error message
	    fi
	fi
    else
	error=1
	if [ "$ForceRun" = "true" ]
	then
	    msg "WARNING: file '$Source' not found - ignored"
	else
	    msg "ERROR: file '$Source' not found"
	    break
	fi
    fi

    if [ "$error" != "0" ] && [ "$ForceRun" != "true" ]
    then break			# Error message was already printed
    fi
done

msg "replaced $copycount file(s)"

exit $error