#!/bin/sh # drop.pew.sk sender: sends files, directories or stdin to whoever runs the # receiver with the same code. POSIX sh + curl, nothing to install. # # curl -fsSL https://drop.pew.sk/s.sh -o /tmp/drop # sh /tmp/drop
 ... [-n NAME] [--keep]
#
#   dir     sent as .tgz
#   -       stdin, named NAME (-n) or stdin-.txt
#   -n      name for stdin, or for the single file given
#   --keep  do not end the transfer afterwards (more sends can follow)
#
# Exit 0 = everything delivered and verified on the receiving side.
set -u

BASE=${DROP_BASE:-https://drop.pew.sk}
PART=94371840   # 90 MiB; Cloudflare refuses request bodies over 100 MB
CODE= NAME= KEEP=0 N=0

die() { printf 'drop: %s\n' "$*" >&2; exit "${RC:-1}"; }

TMP=$(mktemp -d "${TMPDIR:-/tmp}/drop.XXXXXX") || die "mktemp failed"
trap 'rm -rf "$TMP"' EXIT
trap 'exit 130' INT TERM
: > "$TMP/inputs"

while [ $# -gt 0 ]; do
  case $1 in
    -n) [ $# -ge 2 ] || die "-n needs a name"; NAME=$2; shift 2 ;;
    --keep) KEEP=1; shift ;;
    -h|--help) sed -n '2,14p' "$0"; exit 0 ;;
    -) printf '%s\n' "-" >> "$TMP/inputs"; N=$((N + 1)); shift ;;
    -*) die "unknown option $1" ;;
    *)
      if [ -z "$CODE" ]; then CODE=$1
      else
        case $1 in *'
'*) die "file names with newlines are not supported" ;; esac
        printf '%s\n' "$1" >> "$TMP/inputs"; N=$((N + 1))
      fi
      shift ;;
  esac
done
[ -n "$CODE" ] || die "usage: sh s.sh  ... [-n NAME] [--keep]"
printf '%s' "$CODE" | grep -Eq '^[a-hjkmnp-z2-9]{4}(-[a-hjkmnp-z2-9]{4}){3}$' || RC=2 die "not a transfer code: $CODE"
[ "$N" -gt 0 ] || [ "$KEEP" -eq 0 ] || die "nothing to send"
command -v curl >/dev/null 2>&1 || die "curl is required"

if command -v sha256sum >/dev/null 2>&1; then sha() { sha256sum "$1" | cut -d' ' -f1; }
elif command -v shasum >/dev/null 2>&1; then sha() { shasum -a 256 "$1" | cut -d' ' -f1; }
elif command -v openssl >/dev/null 2>&1; then sha() { openssl dgst -sha256 -r "$1" | cut -d' ' -f1; }
else die "need sha256sum, shasum or openssl"; fi

# Everything but unreserved characters becomes %XX, byte by byte.
urlencode() {
  printf '%s' "$1" | od -An -tx1 -v | LC_ALL=C awk '
    BEGIN { hex = "0123456789abcdef" }
    { for (i = 1; i <= NF; i++) {
        n = (index(hex, substr($i, 1, 1)) - 1) * 16 + index(hex, substr($i, 2, 1)) - 1
        if ((n >= 48 && n <= 57) || (n >= 65 && n <= 90) || (n >= 97 && n <= 122) || n == 45 || n == 46 || n == 95 || n == 126)
          printf "%c", n
        else printf "%%%s", toupper($i)
    } }'
}

human() {
  awk -v b="$1" 'BEGIN { split("B KB MB GB TB", u, " "); i = 1
    while (b >= 1000 && i < 5) { b /= 1000; i++ }
    printf (i == 1 ? "%d %s" : "%.1f %s"), b, u[i] }'
}

hint="On the receiving Mac run:  curl -fsSL $BASE/r.sh | sh -s -- $CODE"
WAITED=0   # seconds spent waiting for a receiver, across the whole run

# put_part FILE ID NAME SIZE PART PARTS -- returns once the receiver has it.
put_part() {
  psha=$(sha "$1")
  tries=0
  while :; do
    status=$(curl -sS -X PUT -T "$1" -H 'Expect:' -H 'Content-Type: application/octet-stream' \
      -H "X-Drop-Id: $2" -H "X-Drop-Name: $3" -H "X-Drop-Size: $4" \
      -H "X-Drop-Part: $5" -H "X-Drop-Parts: $6" -H "X-Drop-Sha256: $psha" \
      -D "$TMP/rh" -o "$TMP/resp" -w '%{http_code}' --connect-timeout 20 \
      "$BASE/api/$CODE/file" 2>"$TMP/err")
    case ${status:-000} in
      201) return 0 ;;
      503|409)
        wait=$(grep -i '^retry-after:' "$TMP/rh" | tr -dc '0-9'); [ -n "$wait" ] || wait=5
        [ $WAITED -eq 0 ] && [ "$status" = 503 ] && printf 'drop: receiver not connected yet, waiting (up to 10 min)\n      %s\n' "$hint" >&2
        WAITED=$((WAITED + wait))
        [ $WAITED -le 600 ] || RC=3 die "receiver never connected. $hint"
        sleep "$wait" ;;
      502|504|000)
        tries=$((tries + 1))
        [ $tries -le 3 ] || die "part $(($5 + 1))/$6 of $3 failed 3 times: $(cat "$TMP/resp" "$TMP/err" 2>/dev/null)"
        printf 'drop: part %s/%s interrupted, retrying (%s/3)\n' "$(($5 + 1))" "$6" "$tries" >&2
        sleep 2 ;;
      410) RC=4 die "this transfer has ended; get a new code at $BASE" ;;
      404) RC=2 die "unknown or expired code: $CODE" ;;
      413) RC=5 die "too large: $(cat "$TMP/resp")" ;;
      *) die "HTTP $status: $(cat "$TMP/resp" 2>/dev/null)" ;;
    esac
  done
}

send_file() { # PATH NAME
  size=$(wc -c < "$1" | tr -d ' ')
  id=$(od -An -N12 -tx1 /dev/urandom | tr -d ' \n')
  enc=$(urlencode "$2")
  printf '→ %s  %s\n' "$2" "$(human "$size")"
  if [ "$size" -le $PART ]; then
    put_part "$1" "$id" "$enc" "$size" 0 1
  else
    # One part on disk at a time, cut with dd, rather than split's full copy.
    parts=$(( (size + PART - 1) / PART ))
    i=0
    while [ $i -lt "$parts" ]; do
      dd if="$1" of="$TMP/part" bs=1048576 skip=$((i * 90)) count=90 2>/dev/null || die "cannot read $1"
      put_part "$TMP/part" "$id" "$enc" "$size" "$i" "$parts"
      i=$((i + 1))
      printf '  part %s/%s\n' "$i" "$parts"
    done
    rm -f "$TMP/part"
  fi
  printf '✔ %s\n' "$2"
}

SENT=0
while IFS= read -r arg <&3; do
  if [ "$arg" = - ]; then
    cat > "$TMP/stdin" || die "cannot read stdin"
    send_file "$TMP/stdin" "${NAME:-stdin-$(date +%Y%m%d-%H%M%S).txt}"
  elif [ -d "$arg" ]; then
    dir=$(cd "$arg" && pwd) || die "cannot enter $arg"
    base=$(basename "$dir"); [ "$base" = / ] && base=root
    tar czf "$TMP/dir.tgz" -C "$(dirname "$dir")" "$base" || die "tar failed for $arg"
    send_file "$TMP/dir.tgz" "$base.tgz"
    rm -f "$TMP/dir.tgz"
  elif [ -f "$arg" ]; then
    [ -r "$arg" ] || die "cannot read $arg"
    if [ "$N" -eq 1 ] && [ -n "$NAME" ]; then send_file "$arg" "$NAME"
    else send_file "$arg" "$(basename "$arg")"; fi
  else
    die "no such file or directory: $arg"
  fi
  SENT=$((SENT + 1))
done 3< "$TMP/inputs"

if [ $KEEP -eq 0 ]; then
  curl -sS -X POST -o /dev/null "$BASE/api/$CODE/done" || echo "drop: could not end the transfer (it expires on its own)" >&2
  printf 'drop: %s item(s) delivered, transfer closed\n' "$SENT"
else
  printf 'drop: %s item(s) delivered, code still open (--keep)\n' "$SENT"
fi