Complete Communications Engineering

How Can I Find the Latest Version of a File Using a Linux Shell Script? This depends on exactly what “Latest Version” means.  One possibility is that a directory contains multiple versions of the same file, and the goal is to find one of them.  It could be the one with the most recent timestamp, or if the file names have version numbers it could be the one with the highest version number.  Both of these are possible as the following example demonstrates:

recent.sh

#!/bin/sh

 

RECENT_BY_NAME=$(ls file*.txt | tail -n 1)

RECENT_BY_TIME=$(ls -t file*.txt | head -n 1)

 

echo “Recent by name: $RECENT_BY_NAME”

echo “Recent by time: $RECENT_BY_TIME”

The first command lists files in alphabetical order, which is the default settings for the ‘ls’ command.  The ‘tail’ command prints only the last of these files, so this will find the latest version when version numbers that follow alphabetical order are used.  The second command uses the ‘-t’ option for ‘ls’ which will sort the results based on the modification time of each file.  With this option, the most recently modified file will appear first on the list, so the ‘head’ command will print only the most recently modified file.