implement remote fetching per user-defined frequency

Author: bill-auger

config.ini.example

@@ -0,0 +1,8 @@
+######################################################################
+#  optional user-defined config for the 'git-branch-status' program  #
+#  copy this file to: ./config.ini to customize                      #
+######################################################################
+
+
+# number of minutes between automatic `git fetch --all` calls (0 => always, -1 => never)
+FETCH_PERIOD=-1

git-branch-status

@@ -112,6 +112,18 @@ EXAMPLES:
 USAGE_MSG
 
 
+## user-defined constants (see ./config.ini.example) ##
+
+readonly THIS_DIR="$(dirname "$(readlink -f "${BASH_SOURCE[0]}" 2>/dev/null || echo $0)")"
+readonly CFG_FILE=${THIS_DIR}/config.ini.example
+readonly LAST_FETCH_FILE=${THIS_DIR}/LAST_FETCH
+readonly CFG_FETCH_REGEX='/^\s*FETCH_PERIOD\s*=\s*-?[0-9]+/'
+readonly CFG_AWK_CMD='{ print ($2 + 0) }'
+
+declare -a cfg_fetch_period=($(awk -F '=' "${CFG_FETCH_REGEX}${CFG_AWK_CMD}" ${CFG_FILE} 2>/dev/null))
+readonly FETCH_PERIOD=$([ "${cfg_fetch_period[0]}" ] && echo ${cfg_fetch_period[0]} || echo '-1')
+
+
 ## constants ##
 
 readonly INNER_PADDING_W=13 # '| ' + ' | ' + ' | ' + ' | ' + ' |'
@@ -354,6 +366,19 @@ function Init # (cli_args)
   readonly COMPARE_BRANCH=$branch_b
 }
 
+function FetchRemotes
+{
+  if   (( ${FETCH_PERIOD} >= 0 ))
+  then local now_ts=$(date +%s)
+       local last_fetch_ts=$(awk 'NR==1 { print ($1 + 0) }' ${LAST_FETCH_FILE} 2> /dev/null)
+
+       if   (( ${now_ts} - (${last_fetch_ts} + 0) >= ${FETCH_PERIOD} * 60 ))
+       then git fetch --all
+            echo ${now_ts} > ${LAST_FETCH_FILE}
+       fi
+  fi
+}
+
 function GenerateReports
 {
   if   [ "$COMPARE_BRANCH" ]
@@ -600,4 +625,5 @@ function Reset
 ## main entry ##
 
 Init $*
+FetchRemotes
 GenerateReports