share/mk/install-new.mk

   1 # $Id: install-new.mk,v 1.3 2012/03/24 18:25:49 sjg Exp $
   2 #
   3 #       @(#) Copyright (c) 2009, Simon J. Gerraty
   4 #
   5 #       This file is provided in the hope that it will
   6 #       be of use.  There is absolutely NO WARRANTY.
   7 #       Permission to copy, redistribute or otherwise
   8 #       use this file is hereby granted provided that
   9 #       the above copyright notice and this notice are
  10 #       left intact.
  11 #
  12 #       Please send copies of changes and bug-fixes to:
  13 #       sjg@crufty.net
  14 #
  15
  16 .if !defined(InstallNew)
  17
  18 # copy if src and target are different making a backup if desired
  19 CmpCp= CmpCp() { \
  20         src=$$1 target=$$2 _bak=$$3; \
  21         if ! test -s $$target || ! cmp -s $$target $$src; then \
  22                 trap "" 1 2 3 15; \
  23                 if test -s $$target; then \
  24                         if test "x$$_bak" != x; then \
  25                                 rm -f $$target$$_bak; \
  26                                 mv $$target $$target$$_bak; \
  27                         else \
  28                                 rm -f $$target; \
  29                         fi; \
  30                 fi; \
  31                 cp $$src $$target; \
  32         fi; }
  33
  34 # If the .new file is different, we want it.
  35 # Note: this function will work as is for *.new$RANDOM"
  36 InstallNew= ${CmpCp}; InstallNew() { \
  37         _t=-e; _bak=; \
  38         while :; do \
  39                 case "$$1" in \
  40                 -?) _t=$$1; shift;; \
  41                 --bak) _bak=$$2; shift 2;; \
  42                 *) break;; \
  43                 esac; \
  44         done; \
  45         for new in "$$@"; do \
  46                 if test $$_t $$new; then \
  47                         target=`expr $$new : '\(.*\).new'`; \
  48                         CmpCp $$new $$target $$_bak; \
  49                 fi; \
  50                 rm -f $$new; \
  51         done; :; }
  52
  53 .endif