add setenv.sh

It contains functions to automatically format PGN files as I would like.

1 files changed, 112 insertions, 0 deletions

diff --git a/setenv.sh b/setenv.sh
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+#!/usr/bin/env bash
+
+# Copyright 2016 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is licensed under the terms of the MIT License.
+# See LICENSE.txt for details.
+
+# Utility functions and aliases for "prettifying" PGN files (mostly those
+# downloaded from Chess.com).
+
+# You can use the functions and aliases from this file by "sourcing" it in
+# `bash` (other shells might work as well):
+#
+#     > source setenv.sh
+#
+# `bash` 4.3.42, distributed by the Cygwin project, has been verified to work
+# properly.
+# The dependencies, along with their respective versions that were verified to
+# work properly (also provided by the Cygwin project), are
+#
+# * `coreutils` 8.25,
+# * `sed` 4.2.2.
+#
+# Any Cygwin installation must already have the corresponding packages
+# installed.
+
+# I consider a PGN file to be "pretty" if it
+#
+# 1. has Windows-style newlines (\r\n),
+# 2. places the main line moves on separates lines,
+# 3. doesn't have [%clk] tags after the moves, as those are redundant for
+# storage and analysis (at least that's my opinion currently).
+#
+# The list above is highly subjective of course.
+
+# A word of warning: be very careful when trying to apply the routines from
+# this file to your PGNs, as the result might be disastrous if a PGN is
+# formatted in an unexpected way.
+# You definitely should backup the files prior to trying to "prettify" them.
+#
+# Those precautions aside, if you do want to format PGNs downloaded from
+# Chess.com in a manner I described above, call the `normalize_pgn` function
+# by passing the paths to the PGN files you want to "prettify".
+# For example,
+#
+#     > normalize_pgns Kasparov_vs_Karpov.pgn MyCrushingWin.pgn
+#
+# You can also compress a bunch of PGNs into a single PGN file:
+#
+#     > join_pgns Kasparov_vs_Karpov.pgn MyCrushingWin.pgn > MemorableGames.pgn
+#
+# Or you might want to add a game from a PGN file to a database of games:
+#
+#     > append_pgn MemorableGames.pgn MyCrushingDefeat.pgn
+
+# "Lints" PGN files.
+# Each PGN
+#
+# * has its Unix-style newlines (\n) replaced by Windows-style newlines (\r\n),
+# * gets whitespace characters trimmed from the end of each line,
+# * gets trailing newlines trimmed from the end of the file,
+# * gets a single newline (\r\n) appended at the end of the file.
+lint_pgn() {
+
+    sed --binary --in-place 's/\r\?$/\r/' "$@" \
+        && sed --binary --in-place 's/[[:blank:]]*\(\r\?\)$/\1/' "$@" \
+        && sed --binary --in-place -e :a -e '/^\(\r\n\)*\r$/{$d;N;ba}' "$@" \
+        && sed --binary --in-place '$s/\r\?$/\r/;a\' "$@"
+}
+
+# Strips [%clk] tags from PGN files.
+alias strip_pgn_clk='sed --binary --in-place '"'"'s/ {\[%clk [[:digit:]]\+:[[:digit:]]\+\(:[[:digit:]]\+\)*\]}//g'"'"
+
+# Places main line moves at separate lines.
+alias slice_pgn_moves='sed --binary --in-place '"'"'s/ \([[:digit:]]\+\.\)/\r\n\1/g'"'"
+
+# "Prettifies" PGN files by (see above)
+#
+# * "linting" them,
+# * stripping [%clk] tags,
+# * placing main line moves at separate lines.
+normalize_pgn() {
+    lint_pgn "$@" \
+        && strip_pgn_clk "$@" \
+        && slice_pgn_moves "$@"
+}
+
+append_pgn() {
+    if [ "$#" -ne 2 ]; then
+        echo "usage: $FUNCNAME DEST_PGN SRC_PGN" >&2
+        return 1
+    fi
+
+    printf '\r\n' >> "$1" \
+        && cat "$2" >> "$1"
+}
+
+join_pgns() (
+    if [ "$#" -eq 0 ]; then
+        echo "usage: $FUNCNAME [PGN_FILE]"
+        return 0
+    fi
+
+    set -o errexit
+
+    cat "$1"
+
+    local i
+    for i in "${@:2}"; do
+        printf '\r\n'
+        cat "$i"
+    done
+)