80 lines
1.6 KiB
Lua
80 lines
1.6 KiB
Lua
#!/bin/env lua
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-- Trimmed down cat(1) utility.
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--
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-- Concatenate files to stdout, making sure bytes are actually written
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-- out successfully.
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--
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-- SYNOPSIS:
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-- cat.lua [-u] <FILES...>
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--
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-- NOTE: utility doesn't explicitly allow to concatenate stdin.
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--
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-- Author: Lorenzo Cogotti, The DoubleFourteen Code Forge
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local osx = require 'osx'
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local io = require 'io'
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local uflag = false
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local function cat(path)
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local ferr = io.stderr
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local f, err = io.open(path, 'r')
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if err then
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ferr:write(err, "\n")
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return false
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end
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local success = true -- unless it happens to be a failure
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local fout = io.stdout
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while true do
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local buf, err = f:read(4096)
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if err then
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ferr:write(err, "\n")
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success = false
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end
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if not buf then
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break -- done with file
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end
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assert(fout:write(buf))
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end
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f:close()
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assert(fout:flush())
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if not osx.isatty(fout) then
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assert(osx.commit(fout))
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end
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return success
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end
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local function parseargs(...)
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local files = {}
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for i = 1, select('#', ...) do
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local arg = select(i, ...)
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if arg == '-u' then
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uflag = true
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else
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files[#files+1] = arg
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end
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end
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if #files == 0 then
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error("Missing file arguments")
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end
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return files
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end
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local files = parseargs(...)
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io.stdout:setvbuf(uflag and 'no' or 'full')
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local success = true
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for _, path in ipairs(files) do
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if not cat(path) then
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success = false
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end
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end
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osx.exit(success and 0 or 1)
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