List Files with Epoch Names

In many applications and solutions we create files with timestamp, and a very common method is to use epoch seconds in the name of the files. This is very useful to automated analysis of the files. But, from time to time, we might need to manually analyze the files, and then locating the file with the epoch we want is is tough task. Consider the following files list:

create_time.txt
graphs1702167500-1702171090.json
graphs1702171100-1702174690.json
graphs1702171100-a.json
graphs1702174700-1702178290.json
graphs1702178300-1702181890.json
graphs1702181900-1702185490.json
graphs1702185500-1702189090.json
graphs1702189100-1702192690.json
graphs1702192700-1702196290.json
graphs1702196300-1702199890.json
graphs1702199900-1702203490.json
graphs1702203500-1702205010.json
signatures_1702167500-1702167500.json
signatures_1702167510-1702167510.json
signatures_1702167520-1702167520.json
signatures_1702167530-1702167530.json
signatures_1702167540-1702167540.json
signatures_1702167550-1702167550.json
signatures_1702167560-1702167560.json
signatures_1702167570-1702167570.json
signatures_1702167580-1702167580.json

we can copy the epoch from the file name, and use bash's `date` command to find the actual time of the file, for example:

$ date -u -d @1702171100
Sun 10 Dec 2023 01:18:20 UTC

But doing this for each file is not fun. Instead, we can use a script to automate listing of the files. The following script does the job:

#!/usr/bin/env bash
set -e

folder=$1

ProcessLine() {
  file=$1
  timeDescription="missing epoch"
  epoch1=$(echo "$file" | sed 's/[a-zA-Z_-]*\([0-9]\{10\}\).*/\1/p' | head -1)
  epoch1Length=${#epoch1}
  if [[ "${epoch1Length}" == "10" ]]; then
    date1=$(date +%Y-%m-%dT%H:%M:%S -u -d @${epoch1})
    epoch2=$(echo "$file" | sed 's/.*\([0-9]\{10\}\).*\([0-9]\{10\}\).*/\2/p' | head -1)
    epoch2Length=${#epoch2}
    if [[ "${epoch2Length}" == "10" ]]; then
      date2=$(date +%Y-%m-%dT%H:%M:%S -u -d @${epoch2})
      timeDescription="${date1} to ${date2}"
    else
      timeDescription="${date1}"
    fi
  fi

  sizeDescription=$(ls -lh ${file} | awk '{print $5}')
  sizeDescription=$(printf "%8s %s" ${sizeDescription})
  fileDescription=$(printf "%-50s %s" ${file})

  echo "${fileDescription} ${sizeDescription} ${timeDescription}"
}

ls $1  | while read line; do ProcessLine "$line"; done

The output from the script lists all files in the current working directory, including the file name, size, and user friendly times. It supports files without epoch in the name, files with a single epoch in the name, and files with epoch range in their names. An example output is:

create_time.txt                                           51  missing epoch
graphs1702167500-1702171090.json                        193K  2023-12-10T00:18:20 to 2023-12-10T01:18:10
graphs1702171100-1702174690.json                        193K  2023-12-10T01:18:20 to 2023-12-10T02:18:10
graphs1702171100-a.json                                    0  2023-12-10T01:18:20
graphs1702174700-1702178290.json                        193K  2023-12-10T02:18:20 to 2023-12-10T03:18:10
graphs1702178300-1702181890.json                        181K  2023-12-10T03:18:20 to 2023-12-10T04:18:10
graphs1702181900-1702185490.json                        184K  2023-12-10T04:18:20 to 2023-12-10T05:18:10
graphs1702185500-1702189090.json                        194K  2023-12-10T05:18:20 to 2023-12-10T06:18:10
graphs1702189100-1702192690.json                        195K  2023-12-10T06:18:20 to 2023-12-10T07:18:10
graphs1702192700-1702196290.json                        195K  2023-12-10T07:18:20 to 2023-12-10T08:18:10
graphs1702196300-1702199890.json                        178K  2023-12-10T08:18:20 to 2023-12-10T09:18:10
graphs1702199900-1702203490.json                        190K  2023-12-10T09:18:20 to 2023-12-10T10:18:10
graphs1702203500-1702205010.json                         76K  2023-12-10T10:18:20 to 2023-12-10T10:43:30
signatures_1702167500-1702167500.json                     29  2023-12-10T00:18:20 to 2023-12-10T00:18:20
signatures_1702167510-1702167510.json                     29  2023-12-10T00:18:30 to 2023-12-10T00:18:30
signatures_1702167520-1702167520.json                     29  2023-12-10T00:18:40 to 2023-12-10T00:18:40
signatures_1702167530-1702167530.json                     29  2023-12-10T00:18:50 to 2023-12-10T00:18:50
signatures_1702167540-1702167540.json                     29  2023-12-10T00:19:00 to 2023-12-10T00:19:00
signatures_1702167550-1702167550.json                     29  2023-12-10T00:19:10 to 2023-12-10T00:19:10