some fun iterm2 drawing (#449)

imaging/README.md

@@ -0,0 +1,4 @@
+These nushell scripts are semi-clones of the shell scripts in the same folder. They work with iterm2 on MacOS and maybe other shells.
+
+- divider.nu will print a thick divider line for us with a nushell hook
+- imgcat.nu will print a png image to the terminal screen

imaging/divider.nu

@@ -0,0 +1,8 @@
+def divider [] {
+    let a = "\e]1337;File=inline=1;width=100%%;height=1;preserveAspectRatio=0"
+    let b =  ":"
+    # this is just a 1x1 white png image
+    let c = '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'
+    let d = "\a"
+    [ $a $b $c $d ] | str join
+}

imaging/divider.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+if [ $# -eq 0 ]; then
+  echo "Usage: divider file"
+  exit 1
+fi
+printf '\033]1337;File=inline=1;width=100%%;height=1;preserveAspectRatio=0'
+printf ":"
+base64 < "$1"
+printf '\a\n'

imaging/imgcat.nu

@@ -0,0 +1,91 @@
+# https://iterm2.com/documentation-images.html
+
+def print_osc [] {
+    if $env.TERM == screen* {
+        "\ePtmux;\e\e]"
+    } else {
+        "\e]"
+    }
+}
+
+def print_st [] {
+    if $env.TERM == screen* {
+        "\a\e\\"
+    } else {
+        "\a"
+    }
+}
+
+def-env b64_encode [fn] {
+    open $fn | encode base64
+}
+
+def-env b64_decode [fn] {
+    $fn | decode base64 -b
+}
+
+def print_image [
+    filename # Filename to convey to client
+    inline # 0 or 1
+    base64contents # Base64-encoded contents
+    print_filename # If non-empty, print the filename before outputting the image
+] {
+    let a = (print_osc)
+    let b = "1337;File="
+    let c = (if ($filename | length) > 0 {
+        let b64_enc_data = (b64_encode $filename)
+        $"name=($b64_enc_data);"
+    })
+    let b64_dec_data = (b64_decode $base64contents)
+    let d = $"size=($b64_dec_data | bytes length)"
+    let e = $";inline=($inline)"
+    let f = ":"
+    let g = $base64contents
+    let h = print_st
+    let i = "\n"
+    let j = (if ($print_filename | length) > 0 {
+        print -n $filename
+    })
+
+    [ $a $b $c $d $e $f $g $h $i $j ] | str join
+}
+
+def error [] {
+    print "Error: ($env.LAST_EXIT_CODE)"
+}
+
+def show_help [] {
+    print "Usage: imgcat [-p] filename ..."
+    print "   or: cat filename | imgcat"
+}
+
+# imgcat.nu shows images in your terminal if your terminal supports it
+def imgcat [
+    --help(-h) # Help/Usage message
+    --print(-p) # Print filename
+    --url(-u) # Use a URL
+    filename # The filename to show
+] {
+    if $help {
+        show_help
+    }
+
+    let print_filename = (
+        if $print {
+            1
+        }
+    )
+
+    let url_img = (
+        if $url {
+            let encoded_image = (b64_encode (http get $url))
+            print_image $url 1 $encoded_image $print_filename
+        }
+    )
+
+    if ($filename | path exists) {
+        print_image $filename 1 (b64_encode $filename) $print_filename
+    } else {
+        print $"imgcat: ($filename): No such file or directory"
+    }
+}

imaging/imgcat.sh

@@ -0,0 +1,157 @@
+#!/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
+}
+
+function load_version() {
+    if [ -z ${IMGCAT_BASE64_VERSION+x} ]; then
+        IMGCAT_BASE64_VERSION=$(base64 --version 2>&1)
+        export IMGCAT_BASE64_VERSION
+    fi
+}
+
+function b64_encode() {
+    load_version
+    if [[ $IMGCAT_BASE64_VERSION =~ GNU ]]; then
+        # Disable line wrap
+        base64 -w0
+    else
+        base64
+    fi
+}
+
+function b64_decode() {
+    load_version
+    if [[ $IMGCAT_BASE64_VERSION =~ fourmilab ]]; then
+        BASE64ARG=-d
+    elif [[ $IMGCAT_BASE64_VERSION =~ GNU ]]; then
+        BASE64ARG=-di
+    else
+        BASE64ARG=-D
+    fi
+    base64 $BASE64ARG
+}
+
+# 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 $1 ]]; then
+        printf "name=%s;" "$(printf "%s" "$1" | b64_encode)"
+    fi
+
+    printf "%s" "$3" | b64_decode | wc -c | awk '{printf "size=%d",$1}'
+    printf ";inline=%s" "$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 ] && [ $# -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" | b64_encode) || (
+            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 "$1" 1 "$(b64_encode <"$1")" "$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 | b64_encode)" ""
+fi
+
+exit 0