Merge commit '36d5feed172cb12ccd469abddebf04eaf9a7c9ae' as 'cgilite'

[confetti] / cgilite / storage.sh

diff --git a/cgilite/storage.sh b/cgilite/storage.sh
new file mode 100755 (executable)
index 0000000..7f70e64
--- /dev/null
+++ b/cgilite/storage.sh
@@ -0,0 +1,129 @@
+#!/bin/sh
+
+# Copyright 2018, 2019 Paul Hänsch
+#
+# This is a file format helper, part of CGIlite.
+# 
+# CGIlite is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# CGIlite is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+# 
+# You should have received a copy of the GNU Affero General Public License
+# along with CGIlite.  If not, see <http://www.gnu.org/licenses/>. 
+
+[ -n "$include_storage" ] && return 0
+include_storage="$0"
+
+CR="\r"
+BR='
+'
+
+LOCK(){
+  local lock timeout block
+  lock="${1}.lock"
+  timeout="${2-20}"
+  if [ \! -w "${lock%/*}" ] || [ -e "$lock" -a \! -d "$lock" ]; then
+    printf 'Impossible to get lock: %s\n' "$lock" >&2
+    return 1
+  fi
+
+  while ! mkdir "$lock" 2>&-; do
+    block="$(cat "$lock/pid" || printf 1)"
+    if ! { ps -eo pid |grep -qwF "$block"; }; then
+      printf 'Overriding stale lock: %s\n' "$lock" >&2
+      break
+    fi
+    if [ $timeout -le 0 ]; then
+      printf 'Timeout while trying to get lock: %s\n' "$lock" >&2
+      return 1
+    fi
+    timeout=$((timeout - 1))
+    sleep 1
+  done
+  printf '%i\n' $$ >"${lock}/pid"
+  return 0
+}
+
+RELEASE(){
+  local lock
+  lock="${1}.lock"
+  if [ "$(cat "$lock/pid")" = "$$" ]; then
+    rm "$lock/pid"
+    if ! rmdir "$lock"; then
+      printf 'Cannot remove tainted lock: %s\n' "$lock" >&2
+      printf '%i\n' $$ >"${lock}/pid"
+      return 1
+    fi
+    return 0
+  else
+    printf 'Refusing to release foreign lock: %s\n' "$lock" >&2
+    return 1
+  fi
+}
+
+STRING='
+  s;\\;\\\\;g;
+  s;\n;\\n;g;
+  s;\t;\\t;g;
+  s;\r;\\r;g;
+  s;\+;\\+;g;
+  s; ;+;g;
+'
+
+STRING_OLD(){
+  { [ $# -eq 0 ] && cat || printf %s "$*"; } \
+  | sed -E ':X; $!{N;bX;}'"$STRING"
+}
+
+STRING(){
+  local in out=''
+  [ $# -gt 0 ] && in="$*" || in="$(cat)"
+  while [ "$in" ]; do case $in in
+    \\*) out="${out}\\\\"; in="${in#\\}" ;;
+    "$BR"*) out="${out}\\n"; in="${in#${BR}}" ;;
+    "$CR"*) out="${out}\\r"; in="${in#${CR}}" ;;
+    "  "*) out="${out}\\t"; in="${in#  }" ;;
+    +*) out="${out}\\+"; in="${in#+}" ;;
+    " "*) out="${out}+"; in="${in# }" ;;
+    *) out="${out}${in%%[\\${CR}${BR}  + ]*}"; in="${in#"${in%%[\\${BR}${CR}   + ]*}"}" ;;
+  esac; done
+  printf '%s' "$out"
+}
+
+
+UNSTRING='
+  :UNSTRING_X
+  s;((^|[^\\])(\\\\)*)\\n;\1\n;g;
+  s;((^|[^\\])(\\\\)*)\\t;\1\t;g;
+  s;((^|[^\\])(\\\\)*)\\r;\1\r;g;
+  s;((^|[^\\])(\\\\)*)\+;\1 ;g;
+  tUNSTRING_X;
+  s;((^|[^\\])(\\\\)*)\\\+;\1+;g;
+  s;\\\\;\\;g;
+'
+UNSTRING_OLD(){
+  { [ $# -eq 0 ] && cat || printf %s "$*"; } \
+  | sed -E "$UNSTRING"
+}
+UNSTRING(){
+  local in out=''
+  [ $# -gt 0 ] && in="$*" || in="$(cat)"
+  while [ "$in" ]; do case $in in
+    \\\\*) out="${out}\\"; in="${in#\\\\}" ;;
+    \\n*) out="${out}${BR}"; in="${in#\\n}" ;;
+    \\r*) out="${out}${CR}"; in="${in#\\r}" ;;
+    \\t*) out="${out}  "; in="${in#\\t}" ;;
+    \\+) out="${out}+"; in="${in#\\+}" ;;
+    +*) out="${out} "; in="${in#+}" ;;
+    \\*) in="${in#\\}" ;;
+    *) out="${out}${in%%[\\+]*}"; in="${in#"${in%%[\\+]*}"}" ;;
+  esac; done
+  printf '%s' "$out"
+}
+