utilities: the everyday commands of a talc system.

  where       prints the working directory
  list        what a directory holds             -all -long -time
  show        prints files, or the input
  first       the first lines of a file           -lines -bytes
  last        the last lines of a file            -lines -bytes
  count       lines, words and bytes              -lines -words -bytes
  search      lines that match a pattern          -ignore-case -literal -tree
                                                  -line-numbers -names-only
                                                  -count -invert
  find        paths under a directory             -name -pattern -kind
  copy        files and directories               -tree
  move        files and directories
  remove      files, links and directories        -tree
  create      directories, or empty files         -parents -file
  link        a symbolic link                     -to
  access      who may do what to a file
  owner       whose a file is                     -user -group
  echo        prints its arguments                -no-newline

  utility.talc      what they share: options, complaining, input, trees
  scripts/build.sh  builds them all into bin/

Each one is a program of its own, <name>.talc here, and prints its usage
with -help. In a terminal (../terminal: TERMINAL_FORMS in the
environment) `list` says which names are directories, drawn strong,
and `find` writes every path it found as a link, which a press puts
into the terminal's line (or opens, in ../editor), and `search` writes
each matching line of a file as a link whose target is file:line, which
../editor opens at that line; on a console or in a pipe all three print
plain text, as (system console)'s console-write-styled and
console-write-link arrange. Changing directory is not here: it is the shell's `go`, since
a program cannot move the shell that started it.

Build:

  scripts/build.sh

which needs the installed toolchain (compiler on PATH), and puts the
programs in bin/. Add that directory to PATH to use them.

NAMES. A command is one English word that says what it does, chosen to be
typed many times a day: list, copy, move, remove. An option is one dash
and one word: -all, -tree, -lines 20. There are no one-letter options and
no two-dash ones. The same word means the same thing everywhere it
appears: -tree is always "a directory with everything under it", and a
count is always -lines or -bytes.

An option may come anywhere among the arguments. An argument that begins
with a dash and a letter is an option; a lone dash, or a dash and a digit,
is an ordinary argument. To name a file that begins with a dash, give it a
directory: ./-file.

WHAT THEY HAVE IN COMMON. A utility that reads files takes them as
arguments and reads its input when given none, so it sits in a pipeline
as well as at the end of one. A failure with one argument is complained
about on the error stream, as "name: what went wrong", and the utility
goes on to its next argument; it ends with 1 if anything failed, 2 if the
arguments themselves were wrong (and then prints its usage), and 0
otherwise. search alone ends with 1 to say that nothing matched, and 2
when it could not run.

Users and groups are numbers: this system keeps no file of names. Links
are removed, copied and listed as themselves, not as what they point at,
except that copy follows a link it is given directly. Times are UTC.