examples/scripts.v2/ncp

   1 #! /bin/bash
   2 #
   3 # original from:
   4 # @(#) ncp.ksh,nmv.ksh 1.1 94/07/23
   5 # 92/01/18 john h. dubois iii (john@armory.com)
   6 # 92/01/31 added check for no args left after shifts
   7 # 92/02/17 added help
   8 # 92/02/25 remove path component from filename before tacking it onto dest.
   9 # 92/03/15 exec mv or cp
  10 # 93/07/13 Added -i
  11 # 93/09/29 Made abort if file exists optional.
  12 # 93/11/19 Exit before invoking mv if no files to move
  13 # 94/01/03 Added o option
  14 # 94/04/13 Added x option.
  15 #          Fixed appending of source filename, broken by earlier change.
  16 # 94/07/23 Append only the filename part of the source path.
  17 #
  18 # conversion to bash v2 syntax done by Chet Ramey
  19
  20 false()
  21 {
  22         return 1
  23 }
  24
  25 true()
  26 {
  27         return 0
  28 }
  29
  30 phelp()
  31 {
  32 echo "$name: do a $cmd with extra checking and options.
  33 $Usage
  34 $name is used as a front end for $cmd to get the [icfo] options, and so
  35 that a trailing / will force the last component of the path to be
  36 interpreted as a directory, so that   $name foo bar/   will fail if bar is
  37 not an existing directory, instead of changing the name of foo to bar.
  38 Effectively,  $name foo bar/   is short for  $name foo bar/foo
  39 Options:
  40 -h prints this help.
  41 -c checks first for the existence of each file, and fails if it exists.
  42 -i is like -c except that if the file exists and stdin and stdout are a
  43    tty, a query is printed and a reply is read; a file is overwritten only
  44    if the reply begins with 'y'.
  45 -f unsets -c and -i (in case $cmd is aliased to $name).
  46 -o (overwrite only) checks that the named file(s) exist and fails for any
  47    that do not.  It is the complement of the -c option.
  48 Whichever of [cifo] comes later on the command line determines the behaviour.
  49 Any of these options must come before any standard $cmd options."
  50 }
  51
  52 # interactive: Attempt to overwrite file should result in interactive
  53 # query rather than automatic failure.
  54 # noover: Do not overwrite files (if interactive is true, query, else fail)
  55 # overwrite: Only overwriting is allowed, not creation of new files.
  56 # debug: Print debugging info.
  57 typeset interactive=false noover=false overwrite=false debug=false
  58 name=${0##*/}
  59
  60 case "$name" in
  61 ncp|nmv) cmd=/bin/${name#?} ;;
  62 *) echo "$name: Must be invoked as ncp or nmv." 1>&2 ; exit 2;;
  63 esac
  64
  65 Usage="Usage: $name [-cfhio] $cmd-cmd-line"
  66
  67 while getopts :cfhiox opt; do
  68     case $opt in
  69     h) phelp; exit 0;;
  70     x) debug=true ;;
  71     c) noover=true ;;
  72     i) noover=true ; interactive=true ;;
  73     f) noover=false ; interactive=false ;;
  74     o) overwrite=true ; noover=false ; interactive=false;;
  75     +?) echo "$name: options should not be preceded by a '+'." 1>&2; exit 2;;
  76     ?)  echo "$name: $OPTARG: bad option.  Use -h for help." 1>&2 ; exit 2;;
  77     esac
  78 done
  79
  80 # remove args that were options
  81 shift $((OPTIND - 1))
  82
  83 if [ $# -lt 2 ]; then
  84     echo -e "$Usage\nUse -h for help."
  85     exit
  86 fi
  87
  88 Check()
  89 {
  90     if [ ! -f "$1" ] && $overwrite; then
  91         echo "$name: $1: File does not exist." 1>&2
  92         return 1
  93     elif [ -f "$1" ] && $noover; then
  94         if [ $interactive = false ] || [ ! -t 0 ] || [ ! -t 1 ]; then
  95             echo "$name: $1: File exists." 1>&2
  96             return 1
  97         else
  98             while :; do
  99                 echo -n \
 100 "$name: $1: File exists.  Overwrite? (y)es/(n)o/(a)bort/(Y)es for all: " 1>&2
 101                 read reply
 102                 case "$reply" in
 103                 y*)
 104                     echo "$name: Overwriting $1."
 105                     return 0
 106                     ;;
 107                 Y*)
 108                     echo "$name: Overwriting $1."
 109                     interactive=false
 110                     noover=false
 111                     return 0
 112                     ;;
 113                 [nN]*)
 114                     echo "$name: Skipping $2."
 115                     return 1
 116                     ;;
 117                 [aA]*)
 118                     echo "$name: Aborting."
 119                     exit 1
 120                     ;;
 121                 *)
 122                     echo "$name: Invalid response." 1>&2
 123                     ;;
 124                 esac
 125             done
 126         fi
 127     else
 128         return 0
 129     fi
 130 }
 131
 132 # i is the index of the filename being examined
 133 # lastarg is the index of the last filename before the dest directory name
 134 typeset -i i=0 lastarg=$(($#-1))
 135
 136 # Sets argv[0..$#-1]
 137 argv=("$@")
 138 $debug && echo argv = "${argv[@]}" 1>&2
 139 dest=${argv[lastarg]}
 140
 141 if $debug; then
 142     echo \
 143 "interactive=$interactive noover=$noover overwrite=$overwrite debug=$debug
 144 lastarg=$lastarg dest=$dest name=$name cmd=$cmd
 145 files=$*" 1>&2
 146 fi
 147
 148 if $noover || $overwrite; then
 149     $debug && echo "checking for existance of directories..." 1>&2
 150     # If the destination is not intended to be a directory...
 151     if [ $# -eq 2 ] && [ ! -d "$dest" ]; then
 152         Check "$dest" "$1" || exit 0            # No files to copy
 153     else
 154         while [ $i -lt $lastarg ]; do
 155             Check "$dest/${argv[i]##*/}" "${argv[i]}" || unset argv[i]
 156             let i+=1
 157         done
 158     fi
 159 fi
 160
 161 [ ${#argv[@]} -lt 2 ] && exit 0
 162
 163 # If only 2 args are given, mv/cp will not insist that the destination
 164 # be a directory, which we want if the destination ends in "/" or if
 165 # the original number of args was >2.
 166 # $# is still the original number of args.
 167 # Tack the file name onto the destination to force this behaviour.
 168
 169 lastisslash()
 170 {
 171         case "$1" in
 172         */)     return 0;;
 173         *)      return 1;;
 174         esac
 175 }
 176
 177 if [ ${#argv[@]} = 2 ] && { lastisslash "$2" || [ $# -gt 2 ]; }; then
 178     $debug && echo "Appending filename." 1>&2
 179     # Don't know which element of argv[] holds the source filename,
 180     # since may have started with more than 1 source file & had some unset.
 181     # So, compact args to make it easy to find the set one.
 182     argv=("${argv[@]}")
 183     argv[1]="${argv[1]}/${argv[0]##*/}"
 184 fi
 185
 186 $debug && echo "Executing command: $cmd ${argv[@]}" 1>&2
 187 exec $cmd "${argv[@]}"