WIP2

bin/uxt

@@ -45,14 +45,18 @@ is_integer() {
   [[ "$1" =~ ^-?[[:digit:]]+$ ]]
 }
 
+die() {
+  red_print "Error: $*" >&2
+  exit 1
+}
+
 usage() {
   local -r exit_code=${1:-0}
   (($# > 0)) && shift
   local -r out=$(((exit_code != 0) + 1))
 
   # NOTE: $'foo' is the escape sequence syntax of bash
-  local nl=$'\n' # new line
-  (($# > 0)) && red_print "$*$nl" >&"$out"
+  (($# > 0)) && red_print "$*"$'\n' >&"$out"
 
   cat >&"$out" <<EOF
 Usage: $PROG [OPTION] unix-time [unix-time...]
@@ -139,46 +143,51 @@ done
 
 readonly args unit trim_decimal_tailing_0 no_tz
 
+if [ ${#args[@]} = 0 ]; then
+  usage 1 'No argument provided!' >&2
+fi
+
 ################################################################################
 # biz logic
 ################################################################################
 
-if [ ${#args[@]} = 0 ]; then
-  usage 1 'No argument provided!' >&2
-fi
 for a in "${args[@]}"; do
-  is_integer "$a" || {
-    usage 1 "argument $a is not integer!" >&2
-  }
+  is_integer "$a" || die "argument $a is not integer!"
 done
 
 print_date() {
-  local epoch=$1
+  local input=$1
+  local negative_sign=
+  if [[ $input == -* ]]; then
+    negative_sign=-
+    input=${input#-}
+  fi
 
   # case 1: is unix time in second?
   if [[ $unit = s ]]; then
-    local input_value=$epoch
+    local date_input=$input seconds=$input
     local format_n=
   else
-    local len=${#epoch}
+    local len=${#input}
 
     # case 2: is unix time in millisecond?
     if [[ $unit = ms ]]; then
       if ((len > 3)); then
-        local seconds=${1:0:len-3} decimal=${epoch:len-3:3}
+        local seconds=${1:0:len-3} decimal=${input:len-3:3}
       else
         local seconds=0 decimal
-        printf -v decimal '%03d' "$epoch"
+        printf -v decimal '%03d' "$input"
       fi
     # case 3: auto detect by length
     else
       # for short integer(<= 10 digits), treat as second
       if ((len <= 10)); then
-        local seconds=$epoch decimal=
+        local seconds=$input decimal=
       # for long integer(> 10 digits), treat first 10 digits as second,
       #   and the rest as decimal(use almost 9 digits, aka nano second)
       else
-        local seconds=${epoch:0:10} decimal=${epoch:10:9}
+        ((len <= 19)) || die "too much digits treat(more than 19 digits) as a recent date(treat first 10-digits as seconds, reset at most 9 digits as decimal)"
+        local seconds=${input:0:10} decimal=${input:10:9}
       fi
     fi
 
@@ -191,13 +200,17 @@ print_date() {
       done
     fi
 
-    local input_value=$seconds${decimal:+.$decimal}
+    local date_input=$seconds${decimal:+.$decimal}
     local format_n=${decimal:+.%${#decimal}N}
   fi
 
+  local seconds_value=$negative_sign$seconds
+  ((${#seconds} > 17 || (seconds_value >= -67768040609769944 && seconds_value <= 67768036191647999))) ||
+    die "argument $input(seconds: $seconds_value${decimal:+, decimal: .$decimal}) is out of range! seconds should be in range [-67768040609769944, 67768036191647999]."
+
   local format_tz=' %z'
   $no_tz && format_tz=
-  date -d "@$input_value" +"%Y-%m-%d %H:%M:%S$format_n$format_tz"
+  date -d "@$negative_sign$date_input" +"%Y-%m-%d %H:%M:%S$format_n$format_tz"
 }
 
 for a in "${args[@]}"; do