Add tmux support to it2dl. Issue 9550

Author: gnachman

utilities/it2dl

@@ -4,6 +4,27 @@ if [ $# -lt 1 ]; then
   exit 1
 fi
 
+# tmux requires unrecognized OSC sequences to be wrapped with DCS tmux;
+# <sequence> ST, and for all ESCs in <sequence> to be replaced with ESC ESC. It
+# only accepts ESC backslash for ST. We use TERM instead of TMUX because TERM
+# gets passed through ssh.
+function print_osc() {
+    if [[ $TERM == screen* || $TERM == tmux* ]]; then
+        printf "\033Ptmux;\033\033]"
+    else
+        printf "\033]"
+    fi
+}
+
+# More of the tmux workaround described above.
+function print_st() {
+    if [[ $TERM == screen* || $TERM == tmux* ]]; then
+        printf "\a\033\\"
+    else
+        printf "\a"
+    fi
+}
+
 function load_version() {
     if [ -z ${IT2DL_BASE64_VERSION+x} ]; then
         export IT2DL_BASE64_VERSION=$(base64 --version 2>&1)
@@ -25,11 +46,28 @@ for fn in "$@"
 do
   if [ -r "$fn" ] ; then
     [ -d "$fn" ] && { echo "$fn is a directory"; continue; }
-    printf '\033]1337;File=name=%s;' $(echo -n "$fn" | b64_encode)
-    wc -c "$fn" | awk '{printf "size=%d",$1}'
-    printf ":"
-    base64 < "$fn"
-    printf '\a'
+    if [[ $TERM == screen* || $TERM == tmux* ]]; then
+      print_osc
+      printf '1337;MultipartFile=name=%s;' $(echo -n "$fn" | b64_encode)
+      wc -c "$fn" | awk '{printf "size=%d",$1}'
+      print_st
+
+      parts=$(b64_encode < "$fn" | fold -w 256)
+      for part in $parts; do
+          print_osc
+          printf '1337;FilePart=%s' "$part"
+          print_st
+      done
+      print_osc
+      printf '1337;FileEnd'
+      print_st
+    else
+      printf '\033]1337;File=name=%s;' $(echo -n "$fn" | b64_encode)
+      wc -c "$fn" | awk '{printf "size=%d",$1}'
+      printf ":"
+      base64 < "$fn"
+      printf '\a'
+    fi
   else
     echo File $fn does not exist or is not readable.
   fi