increase portability by getting rid of declare

lib/main.sh

@@ -15,13 +15,7 @@ main_load () {
     local filename=$(basename $file)
     local reporter=${filename%.*}
 
-    # source reporter and copy functions
-    . $file
-    copy_function init      __r_${reporter}_init
-    copy_function report    __r_${reporter}_report
-    copy_function terminate __r_${reporter}_terminate
-    copy_function docs      __r_${reporter}_docs
-    unset -f init report terminate docs
+    load_reporter_with_prefix __r_${reporter}_ $file
 
     __AVAILABLE_REPORTERS=$(trim "$__AVAILABLE_REPORTERS $reporter")
   done
@@ -31,13 +25,7 @@ main_load () {
     local filename=$(basename $file)
     local metric=${filename%.*}
 
-    # soruce metric and copy functions
-    . $file
-    copy_function init      __m_${metric}_init
-    copy_function collect   __m_${metric}_collect
-    copy_function terminate __m_${metric}_terminate
-    copy_function docs      __m_${metric}_docs
-    unset -f init collect terminate docs
+    load_metric_with_prefix __m_${metric}_ $file
 
     # register metric
     __AVAILABLE_METRICS=$(trim "$__AVAILABLE_METRICS $metric")
@@ -109,14 +97,11 @@ main_collect () {
       continue
     fi
 
-    fork () {
-      while true; do
+    # fork
+    (while true; do
         __m_${metric}_collect
         sleep $INTERVAL
-      done
-    }
-    fork &
-    unset -f fork
+    done) &
   done
 
   # run forever

lib/utils/functions.sh

@@ -1,34 +1,6 @@
 #!/bin/sh
 
+# this is bad, but `declare -f -F` is not portable
 is_function () {
-  declare -f -F $1 > /dev/null; return $?
-}
-
-# http://stackoverflow.com/a/1369211/183097
-copy_function () {
-  is_function $1 || return 1
-  eval "$(echo "${2}()"; declare -f ${1} | tail -n +2)"
-}
-
-# if `type declare | grep -q 'shell builtin$'`; then
-#   is_function () {
-#     declare -f -F $1 > /dev/null; return $?
-#   }
-
-#   # http://stackoverflow.com/a/1369211/183097
-#   copy_function () {
-#     is_function $1 || return 1
-#     eval "$(echo "${2}()"; declare -f ${1} | tail -n +2)"
-#   }
-
-# # `declare` is non-posix, provide alternative
-# else
-#   is_function () {
-#     type $1 | grep -q 'shell function$'
-#   }
-
-#   copy_function () {
-#     is_function $1 || return 1
-#     echo "${2}() { ${1} }"
-#   }
-# fi
+  type $1 2> /dev/null | grep -q 'function$'
+}

lib/utils/loader.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+load_metric_with_prefix () {
+  local prefix=$1
+  local file=$2
+
+  local content=$(sed \
+          -e "s/^\s*\(init[ ]*()[ ]*{\)/${prefix}\1/" \
+          -e "s/^\s*\(collect[ ]*()[ ]*{\)/${prefix}\1/" \
+          -e "s/^\s*\(terminate[ ]*()[ ]*{\)/${prefix}\1/" \
+          -e "s/^\s*\(docs[ ]*()[ ]*{\)/${prefix}\1/" $file)
+
+  eval "$content"
+}
+
+load_reporter_with_prefix () {
+  local prefix=$1
+  local file=$2
+  local content=$(sed \
+          -e "s/^\s*\(init[ ]*()[ ]*{\)/${prefix}\1/" \
+          -e "s/^\s*\(report[ ]*()[ ]*{\)/${prefix}\1/" \
+          -e "s/^\s*\(terminate[ ]*()[ ]*{\)/${prefix}\1/" \
+          -e "s/^\s*\(docs[ ]*()[ ]*{\)/${prefix}\1/" $file)
+
+  eval "$content"
+}

metrics/network_io.sh

@@ -13,8 +13,7 @@ init () {
 
 if is_osx; then
   __network_io_collect () {
-    netstat -bI $NETWORK_IO_INTERFACE |
-                    awk "/$NETWORK_IO_INTERFACE/"'{ print $7" "$10 }'
+    netstat -b -I $NETWORK_IO_INTERFACE | awk '{ print $7" "$10 }' | tail -n 1
   }
 else
   __network_io_collect () {
@@ -29,12 +28,14 @@ __network_io_calc_kBps() {
 }
 
 collect () {
-  local sample=( $(__network_io_collect) )
-  if [ ! -z $__network_io_sample ]; then
-    report "in" $(__network_io_calc_kBps ${sample[0]} ${__network_io_sample[0]})
-    report "out" $(__network_io_calc_kBps ${sample[1]} ${__network_io_sample[1]})
+  local sample=$(__network_io_collect)
+  if [ ! -z "$__network_io_sample" ]; then
+    report "in" $(__network_io_calc_kBps $(echo $sample | awk '{print $1}') \
+                                $(echo $__network_io_sample | awk '{print $1}'))
+    report "out" $(__network_io_calc_kBps $(echo $sample | awk '{print $2}') \
+                                $(echo $__network_io_sample | awk '{print $2}'))
   fi
-  __network_io_sample=( "${sample[@]}" )
+  __network_io_sample="$sample"
 }
 
 docs () {