add imgcat

diff --git a/imgcat.sh b/imgcat.sh
new file mode 100644 (file)
index 0000000..b62f670
--- /dev/null
+++ b/imgcat.sh
@@ -0,0 +1,134 @@
+#!/bin/bash
+
+# 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* ]] ; then
+        printf "\033Ptmux;\033\033]"
+    else
+        printf "\033]"
+    fi
+}
+
+# More of the tmux workaround described above.
+function print_st() {
+    if [[ $TERM == screen* ]] ; then
+        printf "\a\033\\"
+    else
+        printf "\a"
+    fi
+}
+
+# print_image filename inline base64contents print_filename
+#   filename: Filename to convey to client
+#   inline: 0 or 1
+#   base64contents: Base64-encoded contents
+#   print_filename: If non-empty, print the filename 
+#                   before outputting the image
+function print_image() {
+    print_osc
+    printf '1337;File='
+    if [[ -n "$1" ]]; then
+      printf 'name='`printf "%s" "$1" | base64`";"
+    fi
+
+    VERSION=$(base64 --version 2>&1)
+    if [[ "$VERSION" =~ fourmilab ]]; then
+      BASE64ARG=-d
+    elif [[ "$VERSION" =~ GNU ]]; then
+      BASE64ARG=-di
+    else
+      BASE64ARG=-D
+    fi
+
+    printf "%s" "$3" | base64 $BASE64ARG | wc -c | awk '{printf "size=%d",$1}'
+    printf ";inline=$2"
+    printf ":"
+    printf "%s" "$3"
+    print_st
+    printf '\n'
+    if [[ -n "$4" ]]; then
+      echo $1
+    fi
+}
+
+function error() {
+    echo "ERROR: $*" 1>&2
+}
+
+function show_help() {
+    echo "Usage: imgcat [-p] filename ..." 1>& 2
+    echo "   or: cat filename | imgcat" 1>& 2
+}
+
+function check_dependency() {
+  if ! (builtin command -V "$1" > /dev/null 2>& 1); then
+    echo "imgcat: missing dependency: can't find $1" 1>& 2
+    exit 1
+  fi
+}
+
+## Main
+
+if [ -t 0 ]; then
+    has_stdin=f
+else
+    has_stdin=t
+fi
+
+# Show help if no arguments and no stdin.
+if [ $has_stdin = f -a $# -eq 0 ]; then
+    show_help
+    exit
+fi
+
+check_dependency awk
+check_dependency base64
+check_dependency wc
+
+# Look for command line flags.
+while [ $# -gt 0 ]; do
+    case "$1" in
+    -h|--h|--help)
+        show_help
+        exit
+        ;;
+    -p|--p|--print)
+        print_filename=1
+        ;;
+    -u|--u|--url)
+        check_dependency curl
+        encoded_image=$(curl -s "$2" | base64) || (error "No such file or url $2"; exit 2)
+        has_stdin=f
+        print_image "$2" 1 "$encoded_image" "$print_filename"
+        set -- ${@:1:1} "-u" ${@:3}
+        if [ "$#" -eq 2 ]; then
+            exit
+        fi
+        ;;
+    -*)
+        error "Unknown option flag: $1"
+        show_help
+        exit 1
+      ;;
+    *)
+        if [ -r "$1" ] ; then
+            has_stdin=f
+            print_image "$1" 1 "$(base64 < "$1")" "$print_filename"
+        else
+            error "imgcat: $1: No such file or directory"
+            exit 2
+        fi
+        ;;
+    esac
+    shift
+done
+
+# Read and print stdin
+if [ $has_stdin = t ]; then
+    print_image "" 1 "$(cat | base64)" ""
+fi
+
+exit 0