upload of csv ledgers

[confetti] / multipart.sh

diff --git a/multipart.sh b/multipart.sh
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+++ b/multipart.sh
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+#!/bin/sh
+
+[ "$include_multipart" ] && return 0
+inlude_multipart="$0"
+
+# Copyright 2022 - 2023 Paul Hänsch
+# 
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+# 
+# THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+# SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+# IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+if [ "${CONTENT_TYPE}" -a ! "${CONTENT_TYPE##multipart/form-data;*}" ]; then
+  multipart_boundary="${CONTENT_TYPE#*; boundary=}"
+  multipart_boundary="${multipart_boundary%%;*}"
+  multipart_boundary="${multipart_boundary%${CR}}"
+fi
+multipart_cachefile="/tmp/multipart.$$"
+
+readbytes(){
+  # read n bytes, like `head -c` but do not consume input
+  local size="$1" block
+
+  for block in 65536 32768 16384 8192 4096 2048 1024 512 256 128 64 32 16 8 4 2 1; do
+    if [ $size -ge $block ]; then
+      dd status=none bs="$block" count="$((size / block))"
+      size="$((size % block))"
+    fi
+  done
+}
+
+multipart_cache() {
+  multipart_cachefile="${1:-${multipart_cachefile}}"  # global
+
+  if [ "${multipart_boundary}" ]; then
+    # readbytes "$(( CONTENT_LENGTH ))" >"${multipart_cachefile}"
+    head -c "$(( CONTENT_LENGTH ))" >"${multipart_cachefile}"
+  else
+    return 1
+  fi
+}
+
+multipart(){
+  local name="$1" count="${2:-1}"
+  local formdata state=begin
+
+  while IFS='' read -r formdata; do case "$formdata" in
+    "--${multipart_boundary}--${CR}")
+      [ $state = data ] && return 0 \
+                        || return 1
+      ;;
+    "--${multipart_boundary}${CR}")
+      [ $state = data ] && return 0 \
+                        || state=header
+      ;;
+    "Content-Disposition: form-data; name=\"${name}\""*"${CR}")
+      [ $state = header -a $count -eq 1 ] && state=dheader
+      [ $state = header -a $count -gt 1 ] && count=$((count - 1))
+      [ $state = data ] && printf "%s\n" "$formdata"
+      ;;
+    "${CR}")
+      if [ $state = dheader ]; then
+        # Do not use `sed -n` (or busybox sed will "convert" NULL to LF)
+        sed "/--${multipart_boundary}\(--\)\?${CR}/{x;q;}" \
+        | head -c-3
+        return 0;
+      fi
+      [ $state = header ] && state=junk
+      ;;
+  esac; done <"${multipart_cachefile}"
+}
+
+multipart_filename(){
+  local name="$1" count="${2:-1}"
+  local formdata state=begin
+
+  while read -r formdata; do case "$formdata" in
+    "--${multipart_boundary}--${CR}")
+      return 1
+      ;;
+    "--${multipart_boundary}${CR}")
+      state=header
+      ;;
+    "Content-Disposition: form-data; name=\"${name}\"; filename=\""*"\""*"${CR}")
+      [ $state = header -a $count -eq 1 ] && break
+      [ $state = header -a $count -gt 1 ] && count=$((count - 1))
+      ;;
+    "${CR}")
+      [ $state = header ] && state=junk
+      ;;
+  esac; done <"${multipart_cachefile}"
+
+  filename="${formdata#*; filename=\"}"
+  filename="${filename%%\"${CR}}"
+  filename="${filename%%\";*}"
+
+  HEX_DECODE % "$filename"
+}