X-Git-Url: http://git.plutz.net/?p=clickslide;a=blobdiff_plain;f=cgilite%2Fstorage.sh;fp=cgilite%2Fstorage.sh;h=0d09b262b4d700dac399dbc165ff5250570d16fa;hp=0000000000000000000000000000000000000000;hb=b771768491f577d83596762d179cc71868bdd9af;hpb=2aa5b9d9d70520a6fb62c9b11e335a49b2856d8d

diff --git a/cgilite/storage.sh b/cgilite/storage.sh
new file mode 100755
index 0000000..0d09b26
--- /dev/null
+++ b/cgilite/storage.sh
@@ -0,0 +1,93 @@
+#!/bin/sh
+
+# Copyright 2018 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="$0"
+
+LOCK(){
+  local lock timeout block
+  lock="${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(){
+  { [ $# -eq 0 ] && cat || printf %s "$*"; } \
+  | sed -r ':X; $!{N;bX;}'"$STRING"
+}
+
+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(){
+  { [ $# -eq 0 ] && cat || printf %s "$*"; } \
+  | sed -r "$UNSTRING"
+}