From 3b62f18221c92ef75cfb80b506ea1ce6d02e3abb Mon Sep 17 00:00:00 2001
From: CyberLeo <cyberleo@cyberleo.net>
Date: Tue, 6 Jan 2009 07:42:51 -0600
Subject: [PATCH] Initial import

---
 flag | 176 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 176 insertions(+)
 create mode 100755 flag

diff --git a/flag b/flag
new file mode 100755
index 0000000..63f44dd
--- /dev/null
+++ b/flag
@@ -0,0 +1,176 @@
+#!/bin/sh
+
+#set -x
+
+# Places for flags:
+# $HOME/.flag-cache <- Autogenerated flag (refreshed when hostname changes)
+# /etc/flag <- Site admin's flag
+# $HOME/.flag <- Local user's flag
+# Check them in that order.
+
+hash_string() {
+  # Hash the passed string into 8 hex characters
+  [ -z "${crc32_bin}" ] && find_crc32_bin
+  if [ -z "${crc32_bin}" ]
+  then
+    echo "No crc32 algo found!" >&2
+    echo "deadbeef"
+  else
+    echo -n "${*}" | eval "${crc32_bin}" | awk '{print $1}'
+  fi
+}
+
+find_crc32_bin() {
+  crc32=""
+  for bin in crc32sum crc32sum-linux crc32sum-freebsd
+  do
+    bin="$(which "${bin}" 2>/dev/null)"
+    if [ -x "${bin}" ]
+    then
+      export crc32_bin="${bin}"
+      if [ "$(hash_string "meow" 2>/dev/null)" = "8a106afe" ]
+      then
+        crc32="${bin}"
+        break
+      fi
+    fi
+  done
+  
+  if [ -z "${crc32}" ]
+  then
+    for bin in ruby php perl
+    do
+      bin="$(which "${bin}" 2>/dev/null)"
+      if [ -x "${bin}" ]
+      then
+        case "${bin}" in
+        */ruby) bin="${bin} -e 'require \"zlib\"; printf(\"%08x\n\", Zlib.crc32(STDIN.readlines.join))'" ;;
+        */php)  bin="${bin} -r 'printf(\"%08x\n\", crc32(file_get_contents(\"/dev/stdin\")));'" ;;
+        */perl)        bin="${bin} -e 'use String::CRC32; printf(\"%08x\n\", crc32(*STDIN));'" ;;
+        esac
+	export crc32_bin="${bin}"
+	if [ "$(hash_string "meow" 2>/dev/null)" = "8a106afe" ]
+	then
+	  crc32="${bin}"
+	  break
+	fi
+      fi
+    done
+  fi
+  if [ -n "${crc32}" ]
+  then
+    export crc32_bin="${crc32}"
+  else
+    echo "Failed to locate usable crc32 algo"
+    unset crc32_bin
+    return 1
+  fi
+}
+
+find_crc32_bin
+
+flagcache(){
+  myhost="$(/bin/hostname -f)"
+  cache="${HOME}/.flag-cache"
+  if [ -f "${cache}" ]
+  then
+    flag_hex="$(awk '/^'${myhost}'/{print $2}' "${cache}")"
+  fi
+  if [ -z "${flag_hex}" ]
+  then
+    flag_hex="$(hash_string "${myhost}")"
+    echo -e "${myhost}\t${flag_hex}" >> "${cache}"
+  fi
+}
+
+if [ -f "${HOME}/.flag" ]
+then
+  flag_hex="$(cat "${HOME}/.flag")"
+fi
+
+if [ -z "${flag_hex}" -a -f "/etc/flag" ]
+then
+  flag_hex="$(cat "/etc/flag")"
+fi
+
+if [ -z "${flag_hex}" ]
+then
+  flagcache
+fi
+
+# Now we definitely have flag_hex
+firstchar() {
+  eval $(echo -en "${data}" | sed -e 's/^\(.\)\(.*\)$/char="\1" data="\2"/g')
+}
+
+hexdec() {
+  if [ -z "${1}" ]
+  then
+    echo "0"
+    return
+  fi
+  echo $(( 0x${1} + 0 ))
+}
+
+flag() {
+  if [ -z "${1}" ]
+  then
+    echo "Usage: flag 'hexcode' [symbol] [shellmode]"
+    echo "Generates an ANSI color flag using the specified hex codes"
+    echo "Uses the optional symbol (or ' ') to draw the flag"
+    echo "shellmode encapsulates all nonprintable codes in \[\] to"
+    echo " give the shell hints on how long the string is, for proper"
+    echo " wrapping of command prompts."
+    return
+  fi
+  data="${1}"
+  sym="${2}"
+  shm="${3}"
+  [ -z "${sym}" ] && sym=" "
+  [ -n "${shm}" ] && open="\[" shut="\]"
+  while [ -n "${data}" ]
+  do
+    firstchar
+    ord=$(hexdec "${char}")
+    bright="0"
+    [ "$(( ${ord} & 8 ))" -gt 0 ] && bright="1"
+    fore="3$(( ${ord} & 7 ))"
+    back="4$(( ${ord} & 7 ))"
+    printf "${open}\033[%s;%s;%s;7m${shut}%s" "${bright}" "${fore}" "${back}" "${sym}"
+  done
+  printf "${open}\033[0m${shut}"
+}
+
+pebkac() {
+   echo "Usage: $(basename "${0}") [-s #] [-e]"
+   echo "Produces a neat little ansi colour 'flag' based off"
+   echo " a hash of the machine's hostname (or settable via"
+   echo " ~/.flag or /etc/flag) which can uniquely visually"
+   echo " identify a machine, at a glance. Useful for placing"
+   echo " into /etc/issue or your bash prompt, so that you"
+   echo " don't send stupid commands to the wrong machine."
+   echo " "
+   echo " -s #   Specify which character should be used to"
+   echo "         render the flag"
+   echo " -e     Turn on bash encapsulation mode, to provide"
+   echo "         hints to Bash on what is or is not printable"
+   echo "         so it can wrap your commands appropriately"
+   echo " "
+   echo "This machine's flag is as such: ($(flag "${flag_hex}"))"
+   exit 1
+}
+
+symbol=" "
+shellmode=""
+
+while [ -n "${1}" ]
+do
+  case "${1}" in
+  -s)	shift; symbol="${1}" ;;
+  -e)	shellmode="yes" ;;
+  *)	pebkac ;;
+  esac
+  shift
+done
+flag "${flag_hex}" "${symbol}" "${shellmode}"
+
-- 
2.42.0