Dogcows Code - chaz/yoink/blob - tools/install.lua

   1 #!/usr/bin/env lua
   2
   3 --
   4 -- Yoink
   5 -- This script is a predictable alternative to the system install program.
   6 --
   7
   8 function show_help()
   9         print([[
  10
  11 Install files, optionally changing the mode of the installed files.
  12 Usage:
  13   install.lua [-m MODE] SOURCE... DEST
  14
  15 If DEST is a directory, the source(s) will be copied into DEST with their
  16 same names.
  17 ]])
  18 end
  19
  20
  21 -- Get the next argument passed to the script.
  22 function shift()
  23         var = arg[1]
  24         table.remove(arg, 1)
  25         return var
  26 end
  27
  28 -- Execute a command and return its output or nil if the command failed to
  29 -- run.
  30 function backtick_run(command)
  31         local fd = io.popen(command.." 2>/dev/null")
  32         if fd then local stdout = fd:read("*l") fd:close() return stdout end
  33         return nil
  34 end
  35
  36 -- Return true if a filespec is a directory, false otherwise.
  37 function is_directory(path)
  38         return os.execute(string.format("test -d %q", path)) == 0
  39 end
  40
  41 -- Get the basename of a path.
  42 function basename(path, ext)
  43         if not ext then ext = "" end
  44         return backtick_run(string.format("basename %q %s", path, ext))
  45 end
  46
  47 -- Get the directory part of a path.
  48 function dirname(path)
  49         if path:sub(-1) == "/" then path = path .. "." end
  50         return backtick_run(string.format("dirname %q", path))
  51 end
  52
  53 -- Like mkdir -p except portable.
  54 function mkdir(path)
  55         if path:sub(1,1) ~= "/" then path = os.getenv("PWD") .. "/" .. path end
  56         path = path:gsub("/$", "")
  57         path = path:gsub("/+", "/")
  58         path = path:gsub("/[^/]+/%.%.", "")
  59         path = path:gsub("%./", "")
  60         path = path:gsub("/%.", "")
  61
  62         local compound = ""
  63         for component in path:gmatch("(/[^/]*)") do
  64                 compound = compound .. component
  65                 if not is_directory(compound) then
  66                         local result = os.execute(string.format("mkdir %q", compound))
  67                         if result ~= 0 then os.exit(1) end
  68                 end
  69         end
  70 end
  71
  72 -- Change the mode of a file or directory.
  73 function chmod(mode, filespec)
  74         if not mode or mode == "" then return end
  75         local result = os.execute(string.format("chmod %s %q", mode, filespec))
  76         if result ~= 0 then os.exit(1) end
  77 end
  78
  79 -- Install a file.  If destination is a directory, the source will be
  80 -- installed into the directory with the same name.
  81 function install(mode, source, dest)
  82         if is_directory(dest) then dest = dest .. "/" .. basename(source) end
  83         local result = os.execute(string.format("cp %q %q", source, dest))
  84         if result == 0 then chmod(mode, dest) else os.exit(1) end
  85 end
  86
  87
  88 files = {}
  89
  90 -- Consume and parse each argument.
  91 while 0 < #arg do
  92         local v = shift()
  93         if v == "-h" or v == "--help" then show_help() os.exit(0) end
  94         if v == "-m" then mode = shift() else table.insert(files, v) end
  95 end
  96
  97 -- Check the arguments and determine the target.
  98 if #files < 2 then show_help() os.exit(1)
  99 else target = table.remove(files) end
 100
 101 -- Perform the installation.
 102 if 1 < #files then
 103         mkdir(target)
 104         for i,file in ipairs(files) do install(mode, file, target) end
 105 else
 106         mkdir(dirname(target))
 107         install(mode, files[1], target)
 108 end
 109