file age

files/file-age

@@ -0,0 +1,48 @@
+#!/bin/bash
+
+_help() {
+  echo '
+Usage: file-age {file} [units]
+
+  Checks file modification date, and the current time. Prints the age of
+  the file in [units].
+  
+  [units] is one of S,M,H,d,w,m,y
+          seconds is the default. All values floored.
+          month = 30 days
+          year = 365 days
+'
+exit
+}
+for (( i=1; i<=$#; i++ ))
+do  [[ "${!i}" = "-h" ]] && _help
+done
+
+STATFILE="$1"
+[[ -z "$STATFILE" ]] && _help
+test -e "$STATFILE" || { echo File "$STATFILE" does not exist >&2; exit 1; }
+
+UNITS=${2:-S}
+created=$( stat -c %Y "$STATFILE" )
+now=$( date +%s )
+age=$(( $now - $created ))
+
+case $UNITS in
+  S)
+    echo $age;;
+  M)
+    echo $(( $age / 60 ));;
+  H)
+    echo $(( $age / 3600 ));;
+  d)
+    echo $(( $age / 86400 ));;
+  w)
+    echo $(( $age / 604800 ));;
+  m)
+    echo $(( $age / 2592000 ));;
+  y)
+    echo $(( $age / 31536000 ));;
+  *)
+    echo Unit $UNITS not recognized.
+    _help;;
+esac