move installed dependency check. update doc

Author: kadwanev

README.md

@@ -35,6 +35,10 @@ Help:
         -x, --max=secs                   Exponential Backoff: maximum sleep amount (seconds): Default 60
         -f, --fail="script +cmds"        Fail Script: run in case of final failure
 
+#### State
+
+Environment variable `RETRY_ATTEMPT` is set with the current attempt number.
+
 ### Examples
 
 No problem:

retry

@@ -7,10 +7,6 @@ __sleep_amount() {
   if [ -n "$constant_sleep" ]; then 
     sleep_time=$constant_sleep
   else
-    if ! command -v awk &> /dev/null; then
-      __log_out "Error: awk not found, please install awk."
-      exit 1
-    fi
     #TODO: check if user would rather use one of the other possible dependencies: python, ruby, bc, dc
     sleep_time=`awk "BEGIN {t = $min_sleep * $(( (1<<($attempts -1)) )); print (t > $max_sleep ? $max_sleep : t)}"`
   fi
@@ -104,6 +100,10 @@ EOF
       echo "I’m sorry, 'getopt --test' failed in this environment. Please load GNU getopt."
       exit 1
   fi
+  if ! command -v awk &> /dev/null; then
+    __log_out "Error: awk not found, please install awk."
+    exit 1
+  fi
 
   OPTIONS=vt:s:m:x:f:
   LONGOPTIONS=verbose,tries:,sleep:,min:,max:,fail: